Keystone weather by month

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

Temperature
Rainfall
Sunshine & UV index

Temperature in Keystone (°F)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Max temperature (daytime)	34	37	45	57	66	77	84	82	73	61	45	36
Min temperature (night-time)	10	14	19	30	41	50	55	54	43	34	21	12
Heat & Humidity	0	0	0	0	0	0	M	L	0	0	0	0

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

Sunshine & UV index in Keystone

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

Rainfall in Keystone

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Number of days with some rain	7	8	9	10	12	12	10	8	8	6	6	7
Average monthly rainfall (inches)	0.4	0.5	0.9	1.8	3.0	3.0	2.4	1.7	1.3	1.0	0.5	0.4

More about Keystone

Keystone by month

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

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The climate guide for South Dakota (Keystone) 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 Keystone?

Keystone has a cold climate with warm summers and some rainfall in all months.

Keystone weather in January

Expect daytime maximum temperatures of 34°F in Keystone, South Dakota in January based on long-term weather averages. There are 5 hours of sunshine per day on average, which might fall as snow.

34
34°F max day temperature
5
5 hours of sunshine per day
7
7 days with some rainfall
10
10°F min night temperature
9
9 hours of daylight per day
0
No heat & humidity
0.4
0.4 inches of monthly rainfall
1
1 (Low) UV index

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Keystone weather in February

Expect daytime maximum temperatures of 37°F in Keystone, South Dakota in February based on long-term weather averages. There are 6 hours of sunshine per day on average, which might fall as snow.

37
37°F max day temperature
6
6 hours of sunshine per day
8
8 days with some rainfall
14
14°F min night temperature
11
11 hours of daylight per day
0
No heat & humidity
0.5
0.5 inches of monthly rainfall
2
2 (Low) UV index

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Keystone weather in March

Expect daytime maximum temperatures of 45°F in Keystone, South Dakota in March based on long-term weather averages. There are 8 hours of sunshine per day on average, which might fall as snow.

45
45°F max day temperature
8
8 hours of sunshine per day
9
9 days with some rainfall
19
19°F min night temperature
12
12 hours of daylight per day
0
No heat & humidity
0.9
0.9 inches of monthly rainfall
4
4 (Moderate) UV index

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Keystone weather in April

Expect daytime maximum temperatures of 57°F in Keystone, South Dakota in April based on long-term weather averages. There are 8 hours of sunshine per day on average with 10 days with some rainfall and typically 1.8 inches of rainfall in the month.

57
57°F max day temperature
8
8 hours of sunshine per day
10
10 days with some rainfall
30
30°F min night temperature
13
13 hours of daylight per day
0
No heat & humidity
1.8
1.8 inches of monthly rainfall
6
6 (High) UV index

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Keystone weather in May

Expect daytime maximum temperatures of 66°F in Keystone, South Dakota 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 3.0 inches of rainfall in the month.

66
66°F max day temperature
9
9 hours of sunshine per day
12
12 days with some rainfall
41
41°F min night temperature
15
15 hours of daylight per day
0
No heat & humidity
3.0
3.0 inches of monthly rainfall
7
7 (High) UV index

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Keystone weather in June

Expect daytime maximum temperatures of 77°F in Keystone, South Dakota in June based on long-term weather averages. There are 10 hours of sunshine per day on average with 12 days with some rainfall and typically 3.0 inches of rainfall in the month.

77
77°F max day temperature
10
10 hours of sunshine per day
12
12 days with some rainfall
50
50°F min night temperature
15
15 hours of daylight per day
0
No heat & humidity
3.0
3.0 inches of monthly rainfall
9
9 (Very High) UV index

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Keystone weather in July

Expect daytime maximum temperatures of 84°F in Keystone, South Dakota in July based on long-term weather averages. There are 11 hours of sunshine per day on average with 10 days with some rainfall and typically 2.4 inches of rainfall in the month.

84
84°F max day temperature
11
11 hours of sunshine per day
10
10 days with some rainfall
55
55°F min night temperature
15
15 hours of daylight per day
M
Moderate heat & humidity
2.4
2.4 inches of monthly rainfall
9
9 (Very High) UV index

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Keystone weather in August

Expect daytime maximum temperatures of 82°F in Keystone, South Dakota in August based on long-term weather averages. There are 10 hours of sunshine per day on average with typically 1.7 inches of rainfall in the month.

82
82°F max day temperature
10
10 hours of sunshine per day
8
8 days with some rainfall
54
54°F min night temperature
14
14 hours of daylight per day
L
Low heat & humidity
1.7
1.7 inches of monthly rainfall
8
8 (Very High) UV index

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Keystone weather in September

Expect daytime maximum temperatures of 73°F in Keystone, South Dakota in September based on long-term weather averages. There are 9 hours of sunshine per day on average.

73
73°F max day temperature
9
9 hours of sunshine per day
8
8 days with some rainfall
43
43°F min night temperature
12
12 hours of daylight per day
0
No heat & humidity
1.3
1.3 inches of monthly rainfall
6
6 (High) UV index

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Keystone weather in October

Expect daytime maximum temperatures of 61°F in Keystone, South Dakota in October based on long-term weather averages. There are 7 hours of sunshine per day on average.

61
61°F max day temperature
7
7 hours of sunshine per day
6
6 days with some rainfall
34
34°F min night temperature
11
11 hours of daylight per day
0
No heat & humidity
1.0
1.0 inches of monthly rainfall
3
3 (Moderate) UV index

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Keystone weather in November

Expect daytime maximum temperatures of 45°F in Keystone, South Dakota in November based on long-term weather averages. There are 5 hours of sunshine per day on average, which might fall as snow.

45
45°F max day temperature
5
5 hours of sunshine per day
6
6 days with some rainfall
21
21°F min night temperature
10
10 hours of daylight per day
0
No heat & humidity
0.5
0.5 inches of monthly rainfall
2
2 (Low) UV index

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Keystone weather in December

Expect daytime maximum temperatures of 36°F in Keystone, South Dakota in December based on long-term weather averages. There are 5 hours of sunshine per day on average, which might fall as snow.