Malheur Experiment Station
Oregon State University
Information for Sustainable Agriculture


1995 Weather Report

J. Mike Barnum, Erik Feibert, and Clint Shock

Malheur Experiment Station

Oregon State University

Ontario, Oregon

Introduction

Daily observations of air temperature and precipitation have been recorded at the Malheur Experiment Station since July 20, 1942. Installation of additional equipment in 1948 allowed for evaporation and wind measurements. A recording soil thermometer was added in 1967. A biophenometer, to monitor growing degree days, and pyranometers, to monitor solar and photosynthetic active radiation, were added in 1985.

Since 1962, daily readings from the station have been reported to the U.S. Department of Commerce, Environmental Science Service Administration, National Weather Service. Each day the 8:00 a.m. air temperature, preceding 24-hour air and soil temperature extremes, and 24-hour accumulated precipitation are recorded and transmitted to radio station KSRV in Ontario. KSRV then conveys this information, along with their own daily readings, to the U.S. Weather Station in Boise, Idaho. During the irrigation season (April -October), evaporation, wind, and water temperature are also monitored and reported.

On June 1, 1992, in cooperation with the U.S. Bureau of Reclamation, a fully automated weather station, connected by satellite to the Northwest Cooperative Agricultural Weather Network (AgriMet) computer in Boise, Idaho, began transmitting data from Malheur Experiment Station. The automated station monitors air temperature, relative humidity, dew point temperature, precipitation, wind run, wind speed, wind direction, solar radiation, and soil temperature at 8-inch and 20-inch depths. Stored data is dumped and transmitted to the Boise computer every 4 hours. The database may be accessed via computer modem. During the irrigation season, daily Malheur County crop water-use estimates, which are based on data from this automated weather station, are also available by modem.

1995 Weather

Total precipitation for the year exceeded the 10-year and 53-year station averages by 43.5 percent and 32.8 percent , respectively (Table 1). With the exception of February, monthly precipitation totals from January through July were above both the 10-year and 53-year means (Table 2). Compared to the long term averages, January and December were abnormally wet (Figure 1). Precipitation accumulation for the fall/winter period October 1, 1994, through March 31, 1995, was 150 percent of the 53-year mean (Table 3).

Snowfall totals for January, February, March, October, and November were below the long-term means. Total snowfall accumulation for December was 149 percent of the 53-year average (Table 4). Annual snowfall for 1995 totaled 75 percent and 78 percent of the 10-year and 53-year averages, respectively (Table 5).

Mean monthly maximum air temperatures from April through August were consistently below the long term station means (Table 6). Mean monthly minimum air temperatures for the same period ranged from 1°F above to 4°F below the 53-year monthly means.

From March through August, monthly mean 4-inch soil temperatures tended to be slightly above the long term means (Table 7). From May through August mean monthly 4-inch soil temperature ranged from 1°F to 4°F above the 29-year monthly mean.

Monthly pan-evaporation totals for April through August ranged from 0.67 inches to 1.42 inches below the monthly mean totals for the past 10 years (Table 8). Mean 1995 daily pan-evaporation from March 1 through August 31 was approximately 0.27 inches per day. Monthly wind-run totals for April 1 through October 31 ranged from 2,449 miles for April to 1,532 miles for September (Table 9). The average daily wind-run over the irrigation season (April through October) was 63 miles per day. The average daily wind-run for the calendar year was 61 miles per day. Total pan-evaporation for the season was 9 percent under the 10-year mean and 5 percent over the 48-year mean (Table 10). Total wind-run for the season exceeded the 10-year mean by 4 percent and 48-year mean by 27 percent. The below-average evaporation figure for 1995 resulted from the occurrence of above-average precipitation amounts and below-average air temperatures throughout most of the irrigation season.

Seasonal estimates of crop water-use for those crops commonly grown in northeastern Malheur County, measured by the Bureau of Reclamation - AgriMet weather station at MES, estimated that crop water requirements for 1995 were below the average requirement for the past 4 years (Table 11).

The last spring frost (<32°F) occurred 10 days earlier than the 20-year mean date of April 26; the first fall frost occurred on September 22, 12 days earlier than normal. Table 12 shows the dates of the last spring and first fall occurrences of minimum air temperatures equal to or below threshold levels of 24, 28, 32, and 36 degrees Fahrenheit for the past 20 years. Table 13 shows the number of days between the last spring occurrence and the first fall occurrence of those threshold temperatures.

Total cumulative growing-degree-days (>50°F and <86°F) for the year were 11 percent below the 10-year mean (Table 14). Although cumulative growing degree days at the end of March were near to the 10-year mean (Figure 2), below-average temperatures from April through September reduced the overall growing-degree-day accumulation.

Record weather events recorded over the 53-year history for the Malheur Experiment Station are listed in Table 15.

Table 1. Annual precipitation totals for 1986 through 1995 and 10-year and 53-year mean annual precipitation totals at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
  1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 10 yr mean 53 yr mean
   inches 
Total 8.64 9.81 7.58 9.15 7.21 9.25 8.64 13.3 10.05 14.01 9.76 10.55

Table 2. Daily and monthly precipitation totals for 1995 and 10-year and 53-year mean monthly precipitation totals at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Day Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
   inches 
1    0.02      0.04             0.01
2   0.08      0.48              
3     0.14   0.02 0.08 0.03          
4     0.20           0.03 0.18   0.06
5     T   0.10       0.04      
6 0.06   T 0.03 0.48 0.08           0.32
7 0.29     0.27 0.02 0.01   T     0.02 0.10
8 0.09     0.13       0.02     0.01  
9 0.20   0.12       0.17       0.07 T
10 0.03   0.03   T   0.09       T 0.11
11 0.10 0.06 0.03 0.06 0.21         0.06 T 0.05
12 0.19 0.07 0.05 0.02 T   0.03     0.11   0.45
13 0.57 0.01 0.20 0.03     0.46       0.11 T
14 0.19 T 0.13 T             0.02 0.10
15 0.06   0.09               0.03 0.22
16 0.02       0.06 0.06   0.02     T 0.23
17   0.03       0.46   0.09     0.02  
18 T 0.01 0.11     0.44       0.09 0.02  
19 0.19   0.32     0.38 0.02          
20 0.01   T 0.25   0.09            
21     T 0.12                
22     0.02             0.01    
23     0.14               T  
24                     0.01  
25                     0.02 T
26 0.12                 0.12 0.03 0.03
27                     T 0.01
28 T     0.06             0.48 0.02
29 0.03     0.01     0.05   T     0.15
30       0.18     0.25       0.04 0.41
31 0.52                     0.29
1995

total

 2.67 0.28 1.58 1.16 1.41 1.60 1.10 0.13 0.07 0.57 0.88 2.56
10 year mean 1.22 0.85 1.09 0.97 1.04 0.94 0.28 0.29 0.30 0.60 1.18 1.01
53 year mean 1.32 0.94 0.97 0.80 1.00 0.82 0.22 0.43 0.50 0.71 1.20 1.33

Table 3. Monthly fall and winter (October through March) precipitation totals from January 1986 through December 1995, and 10-year and 53-year mean monthly and mean seasonal precipitation totals for that six month period at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
    1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 10-year 53-year
Month 1986 / 87 / 88 / 89 / 90 / 91 / 92 / 93 / 94 / 95   mean mean
   inches 
Oct - 0.12 0 0 0.86 0.49 1.01 0.95 0.80 1.23 0.57 1.22 1.32
Nov - 0.22 1.40 2.45 0.24 0.69 1.71 1.15 0.64 2.46 0.88 0.85 0.94
Dec - 0.22 1.46 1.48 0.01 0.29 0.43 1.51 0.60 1.49 2.56 1.09 0.97
Jan 0.96 1.24 1.25 0.88 0.44 0.59 0.58 2.35 1.20 2.67 - 0.60 0.71
Feb 2.29 0.77 0.14 1.27 0.35 0.44 1.36 1.02 0.57 0.28 - 1.18 1.20
Mar 1.24 1.37 0.26 2.17 0.72 0.88 0.25 2.41 0.05 1.58 - 1.01 1.33
Fall1   0.56 2.86 3.93 1.11 1.47 3.15 3.61 2.04 5.18 4.01 3.16 3.23
Spring2 4.49 3.38 1.65 4.32 1.51 1.91 2.19 5.78 1.82 4.53   2.79 3.24
Total   3.94 4.51 8.25 2.62 3.38 5.34 9.39 3.86 9.71   5.95 6.47

Table 4. Daily and monthly snowfall totals for 1995 and 10-year and 53-year mean monthly snowfall totals at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Day  Jan Feb Mar Oct Nov Dec
   inches 
1            
2            
3            
4            
5            
6 0.5         2.5
7 4.0         0.5
8 T          
9            
10            
11   T        
12   1.0        
13   1.0        
14   T        
15            
16            
17            
18 T          
19            
20            
21            
22            
23            
24            
25            
26           T
27           T
28         T T
29           1.5
30           4.0
31            
1995

total

 4.5 2.0 0 0 0 8.5
10 year

mean

 7.8 3.1 0.6 0.1 2.2 6.3
53 year

mean

 7.8 2.8 0.7 0.1 2.1 5.7

Table 5. Annual snowfall totals for 1986 through 1995 and 10-year and 53-year mean annual snowfall totals at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
  1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 10 yr mean 53 yr 
mean
   inches
Total 13.0 15.5 34.8 25.1 5.7 7.5 15.5 36.0 32.0 15.0 20.0 19.2

Table 6. Daily maximum and minimum and monthly mean maximum and minimum air temperatures for 1995 and the 10-year and 53-year mean monthly maximum and minimum air temperatures at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Day max min max min max min max min max min max min max min max min max min max min max min max min
   inches
1 24 1 48 38 52 24 69 43 65 33 86 52 89 57 85 47 91 48 68 40 51 24 59 47
2 21 2 57 34 49 26 57 36 58 45 85 52 92 59 94 56 95 50 68 36 48 13 60 30
3 20 0 58 31 47 31 62 33 63 42 83 53 83 52 95 60 93 54 69 36 46 13 51 25
4 11 0 50 31 50 36 70 37 66 45 83 51 79 52 95 63 93 58 59 41 47 14 50 24
5 23 9 51 32 50 31 74 39 65 48 85 53 82 52 96 60 91 53 61 29 45 16 49 23
6 29 19 52 29 47 24 68 37 57 47 62 39 89 58 100 62 84 50 61 30 54 32 30 17
7 33 23 44 28 45 23 55 41 56 48 58 36 90 56 96 60 86 53 63 35 54 38 29 17
8 35 26 48 34 54 25 63 36 66 49 70 39 92 57 74 43 77 46 67 30 46 34 37 16
9 42 31 53 31 52 34 52 34 64 43 75 51 94 60 77 43 77 47 65 30 51 36 30 16
10 46 38 54 29 60 44 55 30 72 48 71 42 88 62 85 47 80 47 68 34 49 27 33 28
11 54 35 53 27 60 44 59 33 70 49 82 48 89 58 90 51 84 47 63 37 47 27 38 30
12 46 32 32 15 60 41 59 37 63 40 83 49 88 60 82 46 88 47 65 36 49 35 52 32
13 46 32 33 26 57 40 65 38 62 43 87 56 67 48 88 45 90 49 59 27 50 37 65 37
14 44 32 34 20 56 42 53 32 64 40 83 54 76 51 76 42 92 47 60 29 52 42 47 28
15 50 32 33 23 60 43 54 25 70 43 79 51 85 58 86 46 90 47 66 29 51 45 47 29
16 48 31 38 24 56 32 55 30 75 50 70 54 89 57 93 53 92 52 69 28 53 37 43 32
17 45 26 39 24 56 30 61 35 74 52 80 54 93 58 66 50 91 53 72 33 49 39 44 24
18 39 26 45 31 63 34 61 42 77 44 73 48 93 62 74 44 87 51 68 33 52 34 39 24
19 38 31 51 35 55 38 60 34 74 44 69 46 96 66 77 43 89 52 62 29 60 33 41 22
20 41 31 65 32 56 40 56 37 75 43 63 40 94 59 85 45 84 55 62 28 48 30 38 22
21 40 35 62 35 62 34 51 36 81 47 69 43 94 59 91 54 79 42 57 29 53 30 35 23
22 39 22 61 33 52 31 62 39 82 53 73 50 95 60 96 58 67 30 57 34 47 30 35 20
23 40 23 61 34 52 36 66 38 78 52 78 53 90 61 96 63 73 32 59 24 53 29 39 16
24 37 26 63 33 49 29 70 39 78 45 85 53 93 61 95 55 80 37 60 23 50 27 28 17
25 43 32 64 34 48 28 75 46 79 47 89 57 93 57 87 51 77 46 64 32 51 35 23 20
26 41 33 65 42 50 29 70 37 80 48 92 60 95 60 89 50 77 43 60 36 50 36 25 21
27 48 31 62 36 54 29 M M 75 44 95 62 91 58 89 51 75 50 65 35 53 28 26 22
28 46 29 54 27 57 28 74 40 77 47 85 55 95 62 88 46 74 45 59 29 45 30 26 21
29 41 32     56 27 66 42 83 48 84 49 100 63 89 52 71 43 60 28 41 34 33 23
30 45 35     56 26 57 42 87 52 84 49 79 48 81 47 69 38 62 32 56 37 32 26
31 45 37     63 29     90 55     79 47 86 46     53 23     34 27
1995
mean		 39 26 51 30 54 33 62 37 72 46 79 50 89 57 87 51 83 47 63 31 50 31 39 24
10 yr
mean		 33 16 42 22 55 32 66 38 74 46 83 53 90 57 89 54 80 46 67 35 46 26 36 18
53 yr
mean		 34 19 43 25 54 31 64 37 74 45 82 52 91 57 89 55 80 46 65 36 47 28 37 22

Table 7. Daily maximum and minimum and monthly mean maximum and minimum 4-inch soil temperatures for 1995 and the 10-year and 29-year mean monthly maximum and minimum 4-inch soil temperatures at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Day max min max min max min max min max min max min max min max min max min max min max min max min
  inches 
1 34 34 41 39 53 39 64 45 70 50 86 69 89 69 90 69 87 68 68 58 52 41 49 46
2 32 32 43 40 51 39 54 44 57 52 85 68 92 72 91 70 88 69 71 57 51 37 49 40
3 30 30 50 39 48 39 62 40 61 49 85 55 81 70 93 75 86 71 70 56 49 36 44 37
4 32 31 47 38 51 42 67 46 68 49 81 67 82 69 94 76 83 71 61 53 48 35 40 37
5 29 29 48 38 47 40 66 50 67 54 84 67 87 67 94 76 86 70 63 50 45 35 42 36
6 30 30 48 39 45 37 66 54 55 51 67 55 91 70 95 77 85 69 64 49 47 42 36 36
7 31 31 43 39 47 36 58 52 52 50 64 54 89 73 93 78 84 69 62 51 48 42 35 35
8 31 31 45 39 51 37 58 48 61 50 74 54 92 74 83 70 81 67 67 52 46 44 35 35
9 31 31 46 38 42 40 54 44 64 53 76 64 91 74 87 69 83 67 62 51 46 44 35 35
10 32 31 48 38 46 43 55 42 74 53 87 62 85 72 87 68 83 67 65 53 45 41 35 35
11 32 32 44 38 46 44 63 41 72 58 79 61 93 72 87 71 84 67 59 53 47 40 35 35
12 32 32 38 37 55 46 62 48 65 51 85 65 91 74 86 69 85 68 58 51 46 44 44 35
13 33 31 36 36 53 45 60 48 65 50 85 67 74 64 86 69 85 68 58 47 47 44 46 42
14 34 34 35 35 49 46 52 42 62 51 82 69 83 63 81 66 86 68 61 46 50 47 42 38
15 42 33 34 34 52 47 59 42 75 51 79 66 89 64 86 65 84 67 62 47 50 49 40 37
16 40 35 34 34 55 43 63 41 76 55 71 63 92 70 87 69 84 67 62 48 51 46 42 38
17 39 35 34 34 57 42 65 44 80 61 80 63 93 72 74 66 82 68 62 51 50 46 43 37
18 35 35 38 34 55 41 63 48 78 60 71 60 95 74 80 64 83 68 60 50 50 46 37 36
19 35 34 44 36 52 45 62 47 79 59 71 58 92 76 82 64 84 69 60 48 51 43 37 36
20 39 36 51 40 52 45 61 47 82 62 68 54 95 76 84 65 82 69 59 46 45 40 35 35
21 41 36 52 41 51 43 54 44 83 61 72 53 94 76 86 66 80 64 55 46 48 40 35 35
22 38 35 53 42 50 41 59 43 82 64 75 57 94 77 87 70 76 60 55 48 43 40 35 35
23 35 35 55 42 43 40 64 45 87 64 85 62 93 76 89 73 74 59 57 45 48 42 35 34
24 35 35 55 43 47 39 71 48 80 63 89 64 93 76 88 74 76 58 56 44 47 41 34 34
25 38 35 54 42 47 38 74 54 80 62 92 68 93 76 87 72 74 60 59 47 48 44 34 33
26 37 35 57 44 47 38 69 53 80 62 93 72 94 75 88 71 74 62 55 47 45 43 33 33
27 43 36 55 44 46 39 M M 78 61 96 74 92 76 86 70 75 65 61 48 46 38 31 31
28 43 36 54 40 54 40 72 54 82 61 89 72 94 79 88 70 73 63 60 46 40 38 31 31
29 38 36     58 41 68 54 85 63 87 70 95 76 87 69 72 62 58 46 43 39 32 31
30 41 38     60 41 59 51 87 65 88 70 79 66 84 69 72 59 57 46 46 42 32 32
31 40 37     62 41     88 69     87 66 86 69     54 43     32 32
1995

mean

 36 34 46 39 51 41 62 47 73 57 81 63 90 72 87 70 81 66 61 49 47 42 38 36
10 yr

mean

 32 31 38 34 51 41 63 50 73 59 82 67 89 75 87 74 77 65 63 52 44 39 34 32
29 yr

mean

 33 31 38 34 51 41 62 48 74 58 82 67 90 75 88 74 77 64 61 51 44 39 34 33

Table 8. Daily and monthly pan-evaporation1 totals for April through October 1995 and 10-year and 48-year mean monthly pan-evaporation totals for the same period at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Day  Apr May Jun Jul Aug Sep Oct
   inches
1 0.17 0.21 0.21 0.29 0.29 0.26 0.14
2 0.17 0.13 0.34 0.40 0.36 0.32 0.23
3 0.17 0.24 0.29 0.20 0.42 0.23 0.14
4 0.17 0.21 0.29 0.36 0.37 0.22 0.06
5 0.23 0.16 0.32 0.26 0.36 0.29 0.16
6 0.15 0.07 0.24 0.32 0.42 0.30 0.12
7 0.02 0.15 0.16 0.37 0.44 0.28 0.15
8 0.16 0.16 0.41 0.32 0.28 0.30 0.12
9 0.22 0.12 0.27 0.28 0.29 0.22 0.15
10 0.20 0.12 0.18 0.25 0.27 0.22 0.10
11 0.15 0.24 0.37 0.42 0.34 0.26 0.06
12 0.10 0.25 0.35 0.48 0.30 0.25 0.09
13 0.10 0.26 0.36 0.07 0.48 0.26 0.10
14 0.09 0.18 0.33 0.17 0.20 0.26 0.11
15 0.17 0.17 0.18 0.30 0.28 0.24 0.11
16 0.17 0.31 0.16 0.42 0.32 0.26 0.08
17 0.20 0.27 0.34 0.37 0.16 0.22 0.15
18 0.27 0.40 0.20 0.36 0.31 0.24 0.08
19 0.34 0.38 0.14 0.30 0.24 0.40 0.20
20 0.25 0.34 0.25 0.38 0.26 0.34 0.11
21 0.14 0.31 0.25 0.38 0.27 0.39 0.14
22 0.31 0.47 0.08 0.36 0.30 0.20 0.17
23 0.27 0.47 0.26 0.37 0.25 0.22 0.12
22 0.19 0.28 0.30 0.43 0.28 0.20 0.14
25 0.28 0.26 0.29 0.41 0.34 0.20 0.11
26 0.31 0.38 0.31 0.32 0.35 0.26 0.06
27 M 0.49 0.45 0.45 0.33 0.22 0.14
28 0.38 0.33 0.52 0.37 0.29 0.22 0.09
29 0.18 0.34 0.45 0.46 0.23 0.22 0.08
30 0.04 0.29 0.28 0.37 0.32 0.22 0.12
31   0.38   0.25 0.27   0.11
1995
total		 5.60 8.37 8.58 10.49 9.62 7.72 3.74
10 year
mean		 6.27 9.11 9.84 11.91 10.54 7.49 4.30
48 year
mean		 5.54 7.59 8.79 11.09 9.47 6.18 3.07

Table 9. Daily and monthly wind-run1 totals for 1995 and 10-year and 48-year mean monthly April through October wind-run totals at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Day Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
   miles 
1 45 26 58 32 49 44 27 23 31 65 127 124
2 44 49 35 145 64 80 36 49 27 67 48 79
3 46 26 40 59 92 96 56 55 23 31 26 50
4 57 27 73 23 33 66 91 64 42 113 26 62
5 51 15 80 79 50 90 45 37 66 65 37 95
6 9 20 80 65 184 127 41 42 51 33 33 21
7 15 14 27 41 151 79 63 51 50 72 41 57
8 56 57 30 98 79 141 40 110 94 67 30 33
9 184 130 67 108 34 59 48 39 33 38 44 12
10 199 45 157 135 44 24 71 31 26 24 120 37
11 108 93 129 38 47 107 84 81 40 38 61 57
12 32 77 43 20 119 51 108 47 31 60 32 223
13 36 196 85 53 106 65 109 137 28 53 21 220
14 92 70 87 116 70 58 37 44 23 35 18 33
15 42 77 154 100 32 37 37 32 32 30 13 63
16 41 94 69 39 49 65 45 78 29 26 38 99
17 84 35 35 77 68 61 49 58 38 50 30 95
18 24 27 37 91 133 65 42 78 47 51 57 20
19 20 23 66 214 109 51 55 33 77 110 52 35
20 29 31 106 53 31 48 43 26 121 41 25 14
21 38 43 172 183 48 81 41 34 104 67 37 20
22 32 27 57 150 120 36 56 30 52 146 23 13
23 24 30 156 94 125 32 61 26 38 67 31 31
24 32 24 78 40 45 27 71 88 30 40 34 38
25 41 38 143 60 39 27 56 79 45 24 27 14
26 39 33 112 110 113 26 39 43 81 60 63 29
27 28 59 59 M 132 65 78 52 45 71 88 59
28 14 94 96 111 57 124 43 35 43 36 78 32
29 20   66 62 43 81 53 41 113 29 29 27
30 83   33 53 28 36 102 58 72 89 37 45
31 43   33   63   47 27   64   34
1995
total		 1608 1480 2463 2449 2357 1949 1774 1628 1532 1762 1326 1771
10 year mean * * * 2168 2367 1926 1861 1617 1504 1480 * *
48 year mean * * * 2083 1870 1507 1438 1272 1204 1207 * *
1 Total wind movement in miles over 24-hour period measured at approximately 24 inches above ground level.

* Prior to 1990, wind-run data for period between November 1 and March 31 were not recorded at this station.

Table 10. Monthly and seasonal (April through October) pan-evaportation1 and wind-run2 totals for April 1986 through October 1995 and 10-year and 48-year mean monthly and mean seasonal totals for the 7-month irrigation season (April 1 through October 31) at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Year Apr May Jun Jul Aug Sep Oct Total
 
Pan evaporation
   inches
1986 5.80 8.31 10.91 12.00 11.61 5.05 3.95 57.63
1987 8.13 9.55 9.51 11.46 11.08 8.30 4.92 62.95
1988 5.69 8.76 11.17 13.35 11.25 7.01 4.80 62.03
1989 5.79 8.74 10.78 12.84 9.73 6.65 3.76 58.29
1990 7.03 10.07 10.05 12.12 7.88 8.54 3.70 59.39
1991 6.44 8.42 10.12 12.88 11.15 8.36 5.23 62.60
1992 6.40 11.44 9.80 10.49 11.46 6.70 4.15 60.44
1993 4.92 9.28 7.60 10.03 9.51 7.86 4.38 53.58
1994 6.90 8.14 9.90 13.41 12.09 8.69 4.34 63.47
1995 5.60 8.37 8.58 10.49 9.62 7.72 3.74 54.12
10 yr mean 6.27 9.11 9.84 11.91 10.54 7.49 4.30 59.45
48 yr mean 5.54 7.59 8.79 11.09 9.47 6.18 3.07 51.72
  Wind Run
miles 
1986 2308 2321 1792 2130 1740 1413 1544 13248
1987 2354 2432 1898 2161 1938 1620 1311 13714
1988 1889 2599 2357 2014 1879 1604 1294 13636
1989 1929 2620 1872 1707 1481 1465 1311 12385
1990 1832 2506 1824 1556 1276 1357 1427 11778
1991 2693 2677 2184 1680 1358 1316 1786 13694
1992 1797 2237 1711 1671 1580 1583 1158 11737
1993 1943 2060 2008 2138 1604 1505 1273 12531
1994 2490 1865 1669 1780 1686 1648 1929 13067
1995 2449 2357 1949 1774 1628 1532 1762 13451
10 yr mean 2168 2367 1926 1861 1617 1504 1480 12924
48 yr mean 2083 1870 1507 1438 1272 1204 1207 10581

Table 11. Crop water use at Ontario, Oregon. Average calendar dates defining the water use period for those crops commonly grown in the Ontario area and their calculated water use for 1995 and their average use from 1992 through 1995. (This information was developed by the U.S. Bureau of Reclamation using evapotranspiration data generated via the AgriMet weather station located at the Malheur Experiment Station, Oregon State University, Ontario, Oregon.)
  Mean dates defining crop

water use period

 Mean

length

of water

use

period

 Annual calculated

crop water use
 
  Water

use

starts

 Full

canopy

occurs

 Water

use

ends
    Mean
Crop & parameter1 1995 1992-95
   date  days acre inches 
Alfalfa (4 cuts) Mar 14 May 12 Oct 10 211 37.2 39.7
Pasture Mar 11 May 2 Oct 10 213 29.4 31.4
Lawn or turf Mar 11 Apr 17 Oct 10 213 35.6 38.1
Winter grain Mar 9 May 22 Jul 13 126 18.9 22.1
Spring grain (early) Mar 22 Jun 21 Jul 22 122 19.9 22.8
Spring grain (late) Apr 5 Jun 19 Aug 3 120 23.0 24.5
Sugar beet (early) Apr 7 Jul 3 Oct 10 186 * 33.4
Sugar beet (late) Apr 20 Jul 12 Oct 5 168 29.0 31.9
Onion (early) Mar 26 Jul 6 Aug 18 145 25.5 28.3
Onion (mid) Apr 22 Jul 17 Sep 3 134 28.0 28.1
Onion (late) May 6 Jul 26 Sep 8 125 * 26.6
Potato (Shepody) May 2 Jul 3 Aug 29 119 22.7 25.0
Potato (Russet, early) May 4 Jun 23 Sep 10 129 24.1 27.5
Potato (Russet, late) May 19 Jul 14 Sep 18 122 23.1 25.4
Bean (early) May 25 Jul 5 Aug 28 95 25.1 20.1
Bean (late) Jun 8 Jul 8 Sep 4 88 17.5 18.4
Field corn (early) May 7 Jul 18 Sep 15 132 24.3 26.9
Field corn (late) May 22 Jul 28 Sep 18 119 23.0 25.5
Sweet corn (early) May 7 Jul 18 Aug 25 110 19.8 22.0
Sweet corn (late) May 22 Jul 25 Sep 4 105 19.1 21.1
Mint Apr 6 Jun 14 Aug 18 134 30.8 26.9
Apple Apr 15 May 30 Oct 3 170 32.9 36.4
1 Conditions on which evapotranspiration calculations are based.

Table 12. Annual and 20-year mean dates for last occurrence in spring and for first occurrence in fall when the minimum recorded daily air temperature between January 1, 1976, and December 31, 1995, was equal to or below a threshold temperature at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
  Last spring date and first fall date when minimum temperature was < threshold
  Spring Fall
Year <24°F <28°F <32°F <36°F <24°F <28°F <32°F <36°F
1976 Apr 2 Apr 3 Apr 23 Jun 26 Oct 19 Oct 18 Oct 5 Sep 9
1977 Mar 31 Apr 15 Apr 20 May 5 Nov 3 Oct 11 Sep 22 Sep 22
1978 Mar 15 Mar 16 Apr 23 May 25 Oct 26 Oct 23 Oct 14 Sep 19
1979 Feb 7 Mar 19 Mar 20 Mar 26 Nov 10 Nov 2 Oct 27 Oct 10
1980 Mar 17 Mar 26 Apr 13 Apr 16 Oct 23 Oct 17 Oct 17 Sep 22
1981 Mar 18 Apr 14 Apr 14 May 7 Oct 22 Oct 22 Oct 1 Nov 23
1982 Apr 20 Apr 21 May 5 Jun 8 Oct 19 Oct 19 Oct 5 Oct 2
1983 Feb 6 Apr 11 Apr 27 May 14 Dec 2 Oct 16 Sep 20 Sep 10
1984 Mar 5 Apr 7 May 7 May 16 Oct 16 Sep 25 Sep 25 Sep 23
1985 Mar 26 Apr 20 May 13 May 13 Oct 9 Sep 30 Sep 30 Sep 18
1986 Feb 14 Feb 21 May 23 Jul 5 Nov 10 Oct 12 Oct 12 Sep 21
1987 Mar 30 Apr 20 Apr 21 May 2 Nov 18 Oct 11 Oct 11 Sep 27
1988 Mar 13 Apr 10 May 2 May 7 Nov 26 Oct 31 Oct 30 Sep 23
1989 Mar 5 Mar 30 May 19 May 25 Oct 29 Oct 16 Sep 13 Sep 13
1990 Mar 25 Mar 25 May 8 Jun 2 Oct 1 Oct 8 Oct 7 Oct 4
1991 Mar 16 Apr 8 Apr 30 May 9 Oct 30 Oct 30 Oct 4 Oct 4
1992 Feb 6 Apr 8 Apr 24 Apr 25 Nov 11 Oct 7 Sep 14 Sep 9
1993 Mar 12 Mar 12 Apr 20 Jun 12 Oct 30 Oct 27 Oct 11 Sep 17
1994 Mar 24 Mar 28 Apr 15 Jun 8 Nov 8 Oct 28 Oct 6 Oct 6
1995 Mar 7 Apr 15 Apr 16 Jun 7 Oct 23 Oct 13 Sep 22 Sep 22
Mean Mar 12 Apr 2 Apr 26 May 19 Oct 30 Oct 16 Oct 4 Sep 25

Table 13. Annual and 20-year mean number of consecutive days during the year from January 1, 1976, through December 31, 1995, that the minimum recorded daily air temperature was greater than a threshold temperature at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
  Number of days minimum air temperature was greater than threshold
Year <24°F <28°F <32°F <36°F
1976 200 198 165 75
1977 217 179 155 140
1978 225 221 174 117
1979 276 228 221 198
1980 220 205 187 159
1981 218 191 170 200
1982 182 181 153 116
1983 299 188 146 119
1984 225 171 141 130
1985 197 163 140 128
1986 269 233 142 78
1987 233 174 173 148
1988 258 204 181 139
1989 238 200 117 111
1990 190 197 152 124
1991 228 205 157 148
1992 278 182 143 137
1993 232 229 174 97
1994 229 214 174 120
1995 230 181 159 107
Mean 232 197 161 130

Table 14. Monthly cumulative degree days (lower threshold = 50°F, upper threshold = 86°F) for the past 10 years (1986 - 1995) at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1986 0 16 101 220 558 1197 1847 2643 2939 3097 3111 3111
1987 0 0 43 318 741 1288 1929 2578 3064 3287 3316 3318
1988 0 5 56 236 554 1139 2050 2741 3117 3426 3446 3446
1989 0 0 13 197 469 1018 1751 2332 2721 2838 2852 2852
1990 2 9 88 327 588 1085 1819 2454 3039 3077 3077 3077
1991 0 13 29 153 365 754 1530 2248 2684 2878 2879 2879
1992 0 13 119 321 803 1377 2016 2720 3105 3279 3283 3283
1993 0 0 23 104 527 885 1349 1873 2281 2533 2539 2539
1994 0 2 94 283 652 1175 1969 2743 3252 3396 3398 3398
1995 0 29 61 167 460 893 1573 2161 2633 2734 2737 2747
Mean 0 6 63 240 584 1102 1807 2481 2911 3090 3100 3100
Note: One degree day is accumulated for each one degree of the average daily (24-hour) temperature that is above the lower threshold temperature and below the upper threshold temperature.

Table 15. Record weather extremes recorded at Malheur Experiment Station, Oregon State University, Ontario, Oregon.
Event Measurement Date
Greatest annual precipitation 16.87 inches 1983
Greatest 24 hour precipitation 1.52 inches Sep 14, 1959
Greatest annual snowfall 40 inches 1955
Greatest 24 hour snowfall 10 inches Nov 30, 1975 
Earliest first winter snowfall 1 inch Oct 25, 1970
Highest air temperature 108°F Aug 4, 1961
Total days maximum air temperature >100°F 17 days 1971
Lowest minimum air temperature -26°F Feb 21 & 22, 1962
Total days minimum air temperature <0°F 35 days 1985
Lowest 4-inch soil temperature 12°F Dec 24-26, 1990


 
 

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