Annual mean 15°C · wettest around January · prevailing wind W
Warmest
25.8 °C
Coldest
11.5 °C
Wettest
52%
Windiest
4.7 m/s
Prevailing
W
3.7 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
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 Napa over the whole year is 15°C. August is the hottest month, with highs of about 25°C; December is the coldest, with lows of about 7°C. The rainy (wet) season in Napa runs from October to May, peaking in January with a 52% chance of rain on a given day. The dry season is June to September; July is the driest month, at 16%. Winds in Napa are highest in June, averaging 4.0 m/s (14 km/h), and lightest in November, at 2.2 m/s (8 km/h). The prevailing wind is from the W. The clearest skies in Napa come in June, when the sky is typically 15% covered; January is the cloudiest month, at 46%.
Month by month Napa 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
12°C
8°C
10°C
52%
46%
2.5 m/s
10
0
76
February
14°C
7°C
11°C
50%
30%
2.8 m/s
22
0
76
March
15°C
8°C
12°C
51%
40%
3.0 m/s
28
1
80
April
18°C
10°C
16°C
45%
27%
3.2 m/s
56
7
81
May
21°C
12°C
19°C
44%
24%
3.8 m/s
65
18
70
June
24°C
15°C
22°C
25%
15%
4.0 m/s
64
34
52
July
25°C
15°C
24°C
16%
16%
4.0 m/s
61
43
42
August
25°C
15°C
25°C
18%
19%
3.6 m/s
63
46
39
September
25°C
14°C
23°C
29%
19%
3.1 m/s
69
38
48
October
22°C
12°C
20°C
41%
21%
2.5 m/s
75
21
67
November
16°C
9°C
14°C
48%
30%
2.2 m/s
40
1
86
December
12°C
7°C
10°C
51%
42%
2.4 m/s
10
0
75
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 Napa weather by season
Year round, Napa has days of about 12°C at their warmest in January, its coolest month, and 25°C in August, its warmest; the coolest hours of the day run from 7°C to 15°C through the year, and the average temperature over the year is 15°C around the clock. Rain is most likely around January 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.
Napa weather in winterDecember to February
High 13°CLow 7°CRain 51%
Winter in Napa has typical daily highs of about 13°C and lows of about 7°C, with a 51% chance of rain on a given day.
Napa weather in springMarch to May
High 18°CLow 10°CRain 47%
Spring in Napa has typical daily highs of about 18°C and lows of about 10°C, with a 47% chance of rain on a given day.
Napa weather in summerJune to August
High 24°CLow 15°CRain 20%
Summer in Napa has typical daily highs of about 24°C and lows of about 15°C, with a 20% chance of rain on a given day.
Napa weather in autumnSeptember to November
High 21°CLow 12°CRain 39%
Autumn in Napa has typical daily highs of about 21°C and lows of about 12°C, with a 39% chance of rain on a given day.
When is the rainy season in Napa?
The rainy (wet) season in Napa runs from October to May, peaking in January with a 52% chance of rain on a given day. The dry season is June to September; July is the driest month, at 16%.
What time of year is Napa windiest?
Winds in Napa are highest in June, averaging 4.0 m/s (14 km/h), and lightest in November, at 2.2 m/s (8 km/h). The prevailing wind is from the W.
What is the average temperature in Napa year round?
The average temperature in Napa over the whole year is 15°C. August is the hottest month, with highs of about 25°C; December is the coldest, with lows of about 7°C.