Great Falls Weather in September

September in Great Falls averages 23°C (73°F) during the day and 7°C (45°F) at night. The perfect conditions and moderate rainfall make it a solid month to visit.

Rainfall in Great Falls in September

Typically, about 7 days will experience rainfall, with an average of 35 mm (1.4 in) for the month. Neither particularly heavy nor particularly frequent, the rain this month is about average. A light jacket should be enough on most wet days.

Temperature in Great Falls in September

The temperature in Great Falls in September is perfect. Daytime highs reach 23°C (73°F), with nights dropping to 7°C (45°F). Overall, the month follows a fairly predictable daily temperature pattern. At 7°C (45°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.

Sunshine in Great Falls in September

With approximately 255 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.

Wind Speed in Great Falls in September

In September, average wind speeds reach 4 m/s (8 knots), leading to light to moderate breezes. Conditions vary from day to day, with both calm and windier periods.

If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit.

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Great Falls's climate page.

Great Falls Temperature in September

Min Temperature 7°C (45°F)  

Max Temperature 23°C (73°F)  

Chance of Rain 23%  

Precipitation 35 mm (1.4 in)  

Rainy days 7 days  

Humidity 43%  

Windspeed 4 m/s (8 knots)  

Sunshine 255 hours  

Percentage Sunshine  

What to Wear in Great Falls in September

Comfortable temperatures call for an easy wardrobe in September. Pack summer basics like t-shirts and shorts, but include a light jacket for cooler moments. A pair of comfortable walking shoes is essential. Light rain is possible, so consider bringing a small umbrella or rain jacket. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Great Falls in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Cycling

10/10

Walking

10/10

Barbeque

9/10

Camping

5/10

Outdoor sports

10/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Great Falls's climate page.

More climate data for Great Falls

Temperature Rainfall Sunshine Humidity Wind Speed

See the full Great Falls climate overview or explore weather in the United States of America.