Climate Insights for Great Falls

The climate in Great Falls is cool. The average annual temperature is 8°C and approximately 412mm of precipitation falls per year. May is the wettest month, receiving around 66mm of rainfall. Great Falls is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are February, January, December, when temperatures can drop to -8°C. Snowfall occurs from January to December, with around 103cm accumulating over the season.

Great Falls has a wide annual temperature range, spanning 39°C from the coldest to warmest months. The warmest month is July, when average highs reach 31°C and the mean temperature sits around 22°C. The coldest month is February, when overnight lows fall to -8°C and the daily average is -4°C. On average, daily temperatures fluctuate by about 12°C between overnight lows and afternoon highs. The sharpest temperature change occurs between September and October, with a 7°C shift in average temperatures.

Great Falls is a relatively dry area, receiving approximately 412mm of precipitation annually, which averages out to around 34mm per month. The wettest month is May, averaging 66mm of rainfall. June and April also tend to see above-average precipitation. The driest month is July, with just 19mm. That's 47mm less than May, the wettest month. Precipitation varies noticeably between seasons, with the first half (January to June) of the year generally seeing more rainfall. Snowfall is a regular feature from January to December, with around 103cm accumulating over the season. February typically sees the most snow at around 19cm.

Great Falls is moderately windy, with an average annual wind speed of 21km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is November, averaging 24km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in July, with average winds dropping to 19km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 5km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 23km/h in winter, 21km/h in spring, 20km/h in summer, 22km/h in autumn.

It is currently spring in Great Falls, which began on March 20, 2026. Great Falls is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 31°C, while the coldest stretch bottoms out in February near -8°C. Summer is next, beginning on June 21, 2026 — 83 days from now.

The best time to visit Great Falls is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 35mm per month. By contrast, February can be quite cold with temperatures dropping to -8°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Great Falls based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.