Great Falls weather by month

Check out Great Falls weather averages by month. Compare detailed monthly climate statistics including temperature, rainfall and sunshine figures.

Temperature
Rainfall
Sunshine & daylight
UV levels & humidity

Temperature in Great Falls (°C)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Max temperature (daytime)	-2	3	6	13	18	23	28	28	21	15	7	0
Min temperature (night-time)	-12	-8	-6	0	5	9	12	11	6	2	-5	-10
Heat & Humidity	0	0	0	0	0	0	L	L	0	0	0	0

Note: 0 = None, L = Low, M = Moderate, H = High, VH = Very high, E = Extreme

Sunshine & Daylight in Great Falls

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Daily hours of sunshine	4	5	8	8	9	11	12	11	8	6	4	3
Daily hours of daylight	9	10	12	14	15	16	15	14	13	11	9	9
UV Index (Maximum)	1	2	3	5	6	8	8	7	5	3	1	1

Rainfall in Great Falls

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Number of days with some rain	9	7	9	9	12	11	7	8	7	5	6	9
Average monthly rainfall (mm)	20	14	23	31	63	71	34	36	26	19	16	18

More about Great Falls

Great Falls by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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The climate guide for Montana (Great Falls) shows long term monthly weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

What's the climate like in Great Falls?

Great Falls has a cold semi arid climate with warm summers.

Great Falls weather in January

Expect daytime maximum temperatures of -2°C in Great Falls, Montana in January based on long-term weather averages. There are 4 hours of sunshine per day on average, which might fall as snow.

-2
-2°C max day temperature
4
4 hours of sunshine per day
9
9 days with some rainfall
-12
-12°C min night temperature
9
9 hours of daylight per day
0
No heat & humidity
20
20 mm of monthly rainfall
1
1 (Low) UV index

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Great Falls weather in February

Expect daytime maximum temperatures of 3°C in Great Falls, Montana in February based on long-term weather averages. There are 5 hours of sunshine per day on average, which might fall as snow.

3
3°C max day temperature
5
5 hours of sunshine per day
7
7 days with some rainfall
-8
-8°C min night temperature
10
10 hours of daylight per day
0
No heat & humidity
14
14 mm of monthly rainfall
2
2 (Low) UV index

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Great Falls weather in March

Expect daytime maximum temperatures of 6°C in Great Falls, Montana in March based on long-term weather averages. There are 8 hours of sunshine per day on average, which might fall as snow.

6
6°C max day temperature
8
8 hours of sunshine per day
9
9 days with some rainfall
-6
-6°C min night temperature
12
12 hours of daylight per day
0
No heat & humidity
23
23 mm of monthly rainfall
3
3 (Moderate) UV index

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Great Falls weather in April

Expect daytime maximum temperatures of 13°C in Great Falls, Montana in April based on long-term weather averages. There are 8 hours of sunshine per day on average.

13
13°C max day temperature
8
8 hours of sunshine per day
9
9 days with some rainfall
0
0°C min night temperature
14
14 hours of daylight per day
0
No heat & humidity
31
31 mm of monthly rainfall
5
5 (Moderate) UV index

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Great Falls weather in May

Expect daytime maximum temperatures of 18°C in Great Falls, Montana in May based on long-term weather averages. There are 9 hours of sunshine per day on average with 12 days with some rainfall and typically 63 mm of rainfall in the month.

18
18°C max day temperature
9
9 hours of sunshine per day
12
12 days with some rainfall
5
5°C min night temperature
15
15 hours of daylight per day
0
No heat & humidity
63
63 mm of monthly rainfall
6
6 (High) UV index

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Great Falls weather in June

Expect daytime maximum temperatures of 23°C in Great Falls, Montana in June based on long-term weather averages. There are 11 hours of sunshine per day on average with 11 days with some rainfall and typically 71 mm of rainfall in the month.

23
23°C max day temperature
11
11 hours of sunshine per day
11
11 days with some rainfall
9
9°C min night temperature
16
16 hours of daylight per day
0
No heat & humidity
71
71 mm of monthly rainfall
8
8 (Very High) UV index

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Great Falls weather in July

Expect daytime maximum temperatures of 28°C in Great Falls, Montana in July based on long-term weather averages. There are 12 hours of sunshine per day on average.

28
28°C max day temperature
12
12 hours of sunshine per day
7
7 days with some rainfall
12
12°C min night temperature
15
15 hours of daylight per day
L
Low heat & humidity
34
34 mm of monthly rainfall
8
8 (Very High) UV index

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Great Falls weather in August

Expect daytime maximum temperatures of 28°C in Great Falls, Montana in August based on long-term weather averages. There are 11 hours of sunshine per day on average.

28
28°C max day temperature
11
11 hours of sunshine per day
8
8 days with some rainfall
11
11°C min night temperature
14
14 hours of daylight per day
L
Low heat & humidity
36
36 mm of monthly rainfall
7
7 (High) UV index

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Great Falls weather in September

Expect daytime maximum temperatures of 21°C in Great Falls, Montana in September based on long-term weather averages. There are 8 hours of sunshine per day on average.

21
21°C max day temperature
8
8 hours of sunshine per day
7
7 days with some rainfall
6
6°C min night temperature
13
13 hours of daylight per day
0
No heat & humidity
26
26 mm of monthly rainfall
5
5 (Moderate) UV index

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Great Falls weather in October

Expect daytime maximum temperatures of 15°C in Great Falls, Montana in October based on long-term weather averages. There are 6 hours of sunshine per day on average.

15
15°C max day temperature
6
6 hours of sunshine per day
5
5 days with some rainfall
2
2°C min night temperature
11
11 hours of daylight per day
0
No heat & humidity
19
19 mm of monthly rainfall
3
3 (Moderate) UV index

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Great Falls weather in November

Expect daytime maximum temperatures of 7°C in Great Falls, Montana in November based on long-term weather averages. There are 4 hours of sunshine per day on average, which might fall as snow.

7
7°C max day temperature
4
4 hours of sunshine per day
6
6 days with some rainfall
-5
-5°C min night temperature
9
9 hours of daylight per day
0
No heat & humidity
16
16 mm of monthly rainfall
1
1 (Low) UV index

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Great Falls weather in December

Expect daytime maximum temperatures of 0°C in Great Falls, Montana in December based on long-term weather averages. There are 3 hours of sunshine per day on average, which might fall as snow.

0
0°C max day temperature
3
3 hours of sunshine per day
9
9 days with some rainfall
-10
-10°C min night temperature
9
9 hours of daylight per day
0
No heat & humidity
18
18 mm of monthly rainfall
1
1 (Low) UV index

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