Summary of Climatic Data by Month September 2020 - August 31-2021 and Averages for the Years 1949-2021 at the
Eastern Agricultural Research Center, Sidney, MT
Month Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Year
Year 2020 2020 2020 2021 2021 2021 2021 2021 2021 2021 2021 2021  
Precipitation (inches)   Total
   Current Year-Irrigated 0.62 0.19 0.05 0.08 0.11 0.04 0.17 1.64 2.07 0.02 1.07 0.41 6.47
   Average (1981- 2021) 0.91 0.48 0.44 0.40 0.36 0.53 1.12 2.14 2.70 2.05 1.45 1.37 13.95
   Current Year-Dryland 0.62 0.19 0.05 0.08 0.11 0.04 0.30 2.25 2.12 0.52 0.83 0.34 7.45
Temperature (°F)   Average
   Avg. Maximum 49.9 45.0 39.7 34.6 21.9 53.4 57.8 65.8 83.3 90.3 82.8 78.8 58.6
   Avg. Minimum 26.0 20.8 16.0 15.8 22.2 20.4 27.3 40.1 53.4 60.4 53.4 44.7 31.3
   Current Year Avg. Temp 38.0 32.9 27.9 25.2 9.9 36.9 42.6 53.0 68.4 75.4 68.1 61.8 45.0
   Avg. 1949 to 2021 45.7 30.2 18.3 13.5 19.2 30.6 44.4 55.9 64.6 70.2 68.7 58.0 43.3
Last killing frost in springa
2021: May 11, 2021 (31.8 °F)
Average (1949-2021): May 15
Last killing frost in falla
2021: October 19,2021 (27.2 °F)
Average (1949-2021): Septembper 22
Frost-free period
2021: 161 days
Average (1949-2021): 130 days
Growing degree days (base 50)b
May 1 - First killing frost: 2657.5 GDD
Average (1949-2021): 2249.8 GDD

a32 °F is considered a killing frost.
bIn calculating growing degree days, 29 °F is considered a killing frost.
NOTE: Precipitation derived from: NDAWN April - October & National Weather Service November – March. Temperature: NDAWN