Annual mean 11°C · wettest around December · prevailing wind W
Warmest
32.0 °C
Coldest
1.2 °C
Wettest
43%
Windiest
4.7 m/s
Prevailing
W
3.6 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 Boise over the whole year is 11°C. July is the hottest month, with highs of about 32°C; January is the coldest, with lows of about -3°C. Boise has no sharply defined rainy season: the chance of rain on a given day runs from 21% in July, the driest month, to 42% in December, the wettest. Winds in Boise are highest in April, averaging 3.5 m/s (13 km/h), and lightest in September, at 2.4 m/s (9 km/h). The prevailing wind is from the W. The clearest skies in Boise come in July, when the sky is typically 4% covered; December is the cloudiest month, at 59%.
Month by month Boise 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
2°C
-3°C
-2°C
41%
54%
2.6 m/s
0
0
5
February
5°C
-2°C
-0°C
42%
47%
3.0 m/s
0
0
13
March
10°C
2°C
5°C
42%
44%
3.4 m/s
5
0
40
April
15°C
5°C
10°C
41%
31%
3.5 m/s
22
1
63
May
20°C
11°C
16°C
39%
26%
3.4 m/s
55
10
69
June
26°C
15°C
22°C
40%
14%
3.2 m/s
66
36
51
July
32°C
19°C
28°C
21%
4%
2.8 m/s
41
70
15
August
30°C
17°C
27°C
24%
8%
2.6 m/s
53
64
23
September
24°C
11°C
21°C
36%
13%
2.4 m/s
70
27
60
October
16°C
5°C
12°C
37%
23%
2.5 m/s
37
2
71
November
8°C
1°C
4°C
41%
33%
2.5 m/s
3
0
31
December
2°C
-2°C
-3°C
42%
59%
2.5 m/s
0
0
5
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 Boise weather by season
Year round, Boise has days of about 2°C at their warmest in December, its coolest month, and 32°C in July, its warmest; the coolest hours of the day run from -3°C to 19°C through the year, and the average temperature over the year is 11°C around the clock. Rain is most likely around December and least likely around July. 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.
Boise weather in winterDecember to February
High 3°CLow -2°CRain 42%
Winter in Boise has typical daily highs of about 3°C and lows of about -2°C, with a 42% chance of rain on a given day.
Boise weather in springMarch to May
High 15°CLow 6°CRain 40%
Spring in Boise has typical daily highs of about 15°C and lows of about 6°C, with a 40% chance of rain on a given day.
Boise weather in summerJune to August
High 29°CLow 17°CRain 28%
Summer in Boise has typical daily highs of about 29°C and lows of about 17°C, with a 28% chance of rain on a given day.
Boise weather in autumnSeptember to November
High 16°CLow 6°CRain 38%
Autumn in Boise has typical daily highs of about 16°C and lows of about 6°C, with a 38% chance of rain on a given day.
When is the rainy season in Boise?
Boise has no sharply defined rainy season: the chance of rain on a given day runs from 21% in July, the driest month, to 42% in December, the wettest.
What time of year is Boise windiest?
Winds in Boise are highest in April, averaging 3.5 m/s (13 km/h), and lightest in September, at 2.4 m/s (9 km/h). The prevailing wind is from the W.
What is the average temperature in Boise year round?
The average temperature in Boise over the whole year is 11°C. July is the hottest month, with highs of about 32°C; January is the coldest, with lows of about -3°C.