Annual mean 14°C · wettest around December · prevailing wind SW
Warmest
23.3 °C
Coldest
11.5 °C
Wettest
68%
Windiest
4.4 m/s
Prevailing
SW
3.3 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 Petaluma over the whole year is 14°C. September is the hottest month, with highs of about 22°C; December is the coldest, with lows of about 8°C. The rainy (wet) season in Petaluma runs from October to May, peaking in December with a 65% chance of rain on a given day. The dry season is June to September; July is the driest month, at 21%. Winds in Petaluma are highest in June, averaging 3.6 m/s (13 km/h), and lightest in November, at 2.0 m/s (7 km/h). The prevailing wind is from the SW. The clearest skies in Petaluma come in June, when the sky is typically 21% covered; January is the cloudiest month, at 51%.
Month by month Petaluma 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
65%
51%
2.3 m/s
11
0
76
February
13°C
8°C
11°C
64%
35%
2.6 m/s
20
0
75
March
14°C
9°C
12°C
65%
45%
2.6 m/s
25
1
78
April
16°C
10°C
15°C
61%
32%
2.9 m/s
49
5
80
May
18°C
12°C
18°C
58%
30%
3.3 m/s
60
13
74
June
21°C
13°C
20°C
34%
21%
3.6 m/s
62
25
61
July
21°C
14°C
22°C
21%
24%
3.3 m/s
66
35
51
August
22°C
14°C
23°C
24%
27%
3.0 m/s
70
37
48
September
22°C
14°C
22°C
41%
27%
2.6 m/s
71
31
55
October
20°C
12°C
20°C
54%
28%
2.2 m/s
72
18
68
November
16°C
9°C
14°C
62%
35%
2.0 m/s
38
1
84
December
12°C
8°C
10°C
65%
47%
2.1 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 Petaluma weather by season
Year round, Petaluma has days of about 12°C at their warmest in January, its coolest month, and 22°C in September, its warmest; the coolest hours of the day run from 8°C to 14°C through the year, and the average temperature over the year is 14°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.
Petaluma weather in winterDecember to February
High 13°CLow 8°CRain 65%
Winter in Petaluma has typical daily highs of about 13°C and lows of about 8°C, with a 65% chance of rain on a given day.
Petaluma weather in springMarch to May
High 16°CLow 10°CRain 61%
Spring in Petaluma has typical daily highs of about 16°C and lows of about 10°C, with a 61% chance of rain on a given day.
Petaluma weather in summerJune to August
High 21°CLow 14°CRain 27%
Summer in Petaluma has typical daily highs of about 21°C and lows of about 14°C, with a 27% chance of rain on a given day.
Petaluma weather in autumnSeptember to November
High 19°CLow 12°CRain 52%
Autumn in Petaluma has typical daily highs of about 19°C and lows of about 12°C, with a 52% chance of rain on a given day.
When is the rainy season in Petaluma?
The rainy (wet) season in Petaluma runs from October to May, peaking in December with a 65% chance of rain on a given day. The dry season is June to September; July is the driest month, at 21%.
What time of year is Petaluma windiest?
Winds in Petaluma are highest in June, averaging 3.6 m/s (13 km/h), and lightest in November, at 2.0 m/s (7 km/h). The prevailing wind is from the SW.
What is the average temperature in Petaluma year round?
The average temperature in Petaluma over the whole year is 14°C. September is the hottest month, with highs of about 22°C; December is the coldest, with lows of about 8°C.