Annual mean 8°C · wettest around May · prevailing wind NW
Warmest
29.3 °C
Coldest
-4.0 °C
Wettest
19%
Windiest
5.5 m/s
Prevailing
NW
4.2 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Helena over the whole year is 8°C. July is the hottest month, with highs of about 28°C; February is the coldest, with lows of about -8°C. Helena has no sharply defined rainy season: the chance of rain on a given day runs from 8% in January, the driest month, to 18% in May, the wettest. Winds in Helena are highest in April, averaging 3.9 m/s (14 km/h), and lightest in January, at 2.9 m/s (10 km/h). The prevailing wind is from the NW. The clearest skies in Helena come in July, when the sky is typically 13% covered; February is the cloudiest month, at 50%.
Month by month Helena climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
-3°C
-7°C
-8°C
8%
45%
2.9 m/s
0
0
0
February
-3°C
-8°C
-8°C
11%
50%
3.6 m/s
0
0
4
March
5°C
-3°C
-1°C
10%
43%
3.4 m/s
2
0
16
April
11°C
2°C
5°C
14%
41%
3.9 m/s
9
0
41
May
17°C
8°C
12°C
18%
42%
3.6 m/s
37
3
68
June
22°C
13°C
18°C
16%
29%
3.6 m/s
64
16
68
July
28°C
17°C
24°C
12%
13%
3.2 m/s
66
54
36
August
26°C
15°C
23°C
11%
16%
3.0 m/s
73
45
45
September
20°C
10°C
16°C
16%
26%
3.0 m/s
60
14
69
October
12°C
3°C
7°C
13%
36%
3.2 m/s
20
0
53
November
4°C
-2°C
-1°C
8%
38%
3.3 m/s
1
0
16
December
-1°C
-5°C
-6°C
8%
46%
3.1 m/s
0
0
4
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Helena weather by season
Year round, Helena has days of about -3°C at their warmest in January, its coolest month, and 28°C in July, its warmest; the coolest hours of the day run from -8°C to 17°C through the year, and the average temperature over the year is 8°C around the clock. Rain is most likely around May and least likely around January. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Helena weather in winterDecember to February
High -2°CLow -7°CRain 9%
Winter in Helena has typical daily highs of about -2°C and lows of about -7°C, with a 9% chance of rain on a given day.
Helena weather in springMarch to May
High 11°CLow 3°CRain 14%
Spring in Helena has typical daily highs of about 11°C and lows of about 3°C, with a 14% chance of rain on a given day.
Helena weather in summerJune to August
High 25°CLow 15°CRain 13%
Summer in Helena has typical daily highs of about 25°C and lows of about 15°C, with a 13% chance of rain on a given day.
Helena weather in autumnSeptember to November
High 12°CLow 4°CRain 12%
Autumn in Helena has typical daily highs of about 12°C and lows of about 4°C, with a 12% chance of rain on a given day.
When is the rainy season in Helena?
Helena has no sharply defined rainy season: the chance of rain on a given day runs from 8% in January, the driest month, to 18% in May, the wettest.
What time of year is Helena windiest?
Winds in Helena are highest in April, averaging 3.9 m/s (14 km/h), and lightest in January, at 2.9 m/s (10 km/h). The prevailing wind is from the NW.
What is the average temperature in Helena year round?
The average temperature in Helena over the whole year is 8°C. July is the hottest month, with highs of about 28°C; February is the coldest, with lows of about -8°C.