Great Falls, Montana Climate by Month
Great Falls, Montana, United States
Hot summers and freezing winters, with rain spread through the year.
The climate in Great Falls is one of hot summers and freezing winters, with rain spread through the year. Afternoon highs range from 35°F (2°C) in January to 86°F (30°C) in July, and January nights average 16°F (-9°C). About 14 in (352 mm) of rain falls in a typical year, with no clear rainy season.
- Warmest month
- 86°F(30°C)
- Average high, July
- Coldest nights
- 16°F(-9°C)
- Average low, January
- Rain per year
- 14 in(352 mm)
- No clear rainy season
- Humidity
- 53%
- Sunniest: July
Best and worst months in Great Falls
Best for weatherJune and September are the best time for weather in Great Falls: highs near 74°F (23°C) and about 2.0 in (50 mm) of rain a month.
Least pleasantDecember and January are the least pleasant; January is the coldest, with highs of only 35°F (2°C).
Comfort combines how close the afternoon high is to 75°F (24°C) with how much rain falls and how humid it is. See where the weather is best in September.
Temperature and rain through the year
Highs and lows (°F)
Average highAverage low
Rain (in per month)
Great Falls weather by month
| Month | High | Low | Rain | Humidity | Sun |
|---|---|---|---|---|---|
| JanJanuary | 35°F(2°C) | 16°F(-9°C) | 0.6 in(14 mm) | 64% | 1.4 |
| FebFebruary | 38°F(3°C) | 16°F(-9°C) | 0.6 in(14 mm) | 61% | 2.4 |
| MarMarch | 47°F(8°C) | 24°F(-4°C) | 0.8 in(20 mm) | 57% | 3.7 |
| AprApril | 57°F(14°C) | 32°F(0°C) | 1.5 in(39 mm) | 50% | 4.6 |
| MayMay | 67°F(19°C) | 41°F(5°C) | 2.3 in(59 mm) | 50% | 5.8 |
| JunJuneBest | 75°F(24°C) | 48°F(9°C) | 2.8 in(72 mm) | 54% | 6.1 |
| JulJuly | 86°F(30°C) | 54°F(12°C) | 1.0 in(26 mm) | 44% | 6.9 |
| AugAugust | 85°F(30°C) | 52°F(11°C) | 1.2 in(30 mm) | 38% | 5.9 |
| SepSeptemberBest | 74°F(23°C) | 44°F(7°C) | 1.1 in(28 mm) | 47% | 4.2 |
| OctOctober | 59°F(15°C) | 34°F(1°C) | 0.9 in(23 mm) | 56% | 2.6 |
| NovNovember | 45°F(7°C) | 25°F(-4°C) | 0.5 in(13 mm) | 58% | 1.6 |
| DecDecember | 36°F(2°C) | 17°F(-8°C) | 0.6 in(14 mm) | 62% | 1.2 |
1991–2020 averages. Sun is solar radiation in kWh/m² per day. Highlighted: the most comfortable months.
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