Great Falls, MT

Climate overview — based on NOAA 1991-2020 normals from GREAT FALLS 16ST, MT US.

BSk Semi-arid (cold) climate 7a USDA hardiness Zone 7a

Year-round temperatures (°F)

10° 30° 50° 70° 90° J F M A M J J A S O N D
Avg high Avg low

Climate summary

Great Falls has an annual average temperature of 47°F with about 15.4 inches of precipitation per year. The warmest month is July (average high 85.8°F), and the coldest is January (average low 17.5°F). June is typically the wettest month (2.74 in) and December the driest (0.56 in).

Annual swing
43.2°F
warmest to coldest month
Heating need
6,741
Cooling need
273

Best time to visit Great Falls

Full guide →

Climate change signal

All-time records →

48 of 366 (13.1%) of Great Falls's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.

1890s
53
1900s
17
1910s
66
1920s
34
1930s
71
1950s
36
2000s
22
2010s
53
2020s
14

Bars: number of all-time daily heat records still standing that were set in each decade.

Monthly averages

Month Avg High Avg Low Avg Temp Precipitation Snow Rainy days
January 36.8°F 17.5°F 27.2°F 0.61 in 6
February 38.6°F 18.7°F 28.7°F 0.58 in 9
March 48.2°F 25.2°F 36.7°F 0.63 in 6
April 58.3°F 33.2°F 45.7°F 1.79 in 9
May 67.0°F 41.9°F 54.4°F 2.66 in 11
June 75.4°F 49.6°F 62.5°F 2.74 in 9
July 85.8°F 55.0°F 70.4°F 1.34 in 6
August 83.9°F 53.4°F 68.7°F 1.30 in 6
September 72.6°F 44.7°F 58.6°F 1.39 in 7
October 59.1°F 35.9°F 47.5°F 1.13 in 7
November 45.3°F 26.0°F 35.7°F 0.70 in 6
December 36.7°F 19.8°F 28.3°F 0.56 in 7

Climate twins of Great Falls

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

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