Annual mean 14°C · wettest around January · prevailing wind W
Warmest
20.3 °C
Coldest
11.7 °C
Wettest
97%
Windiest
4.6 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
never good
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 Mill Valley over the whole year is 14°C. September is the hottest month, with highs of about 20°C; February is the coldest, with lows of about 9°C. The rainy (wet) season in Mill Valley runs from October to May, peaking in January with a 94% chance of rain on a given day. The dry season is June to September; July is the driest month, at 45%. Winds in Mill Valley are highest in June, averaging 3.6 m/s (13 km/h), and lightest in October, at 2.3 m/s (8 km/h). The prevailing wind is from the W. The clearest skies in Mill Valley come in June, when the sky is typically 27% covered; January is the cloudiest month, at 50%.
Month by month Mill Valley 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
10°C
11°C
94%
50%
2.6 m/s
11
0
76
February
13°C
9°C
10°C
93%
35%
2.9 m/s
13
0
72
March
14°C
10°C
11°C
94%
45%
2.9 m/s
15
0
76
April
15°C
11°C
13°C
93%
34%
3.1 m/s
32
2
78
May
16°C
12°C
15°C
91%
35%
3.4 m/s
42
6
78
June
18°C
13°C
16°C
53%
27%
3.6 m/s
45
11
73
July
18°C
14°C
18°C
45%
33%
3.4 m/s
57
17
68
August
19°C
15°C
20°C
46%
35%
3.1 m/s
70
19
66
September
20°C
15°C
19°C
66%
33%
2.6 m/s
69
16
70
October
19°C
13°C
18°C
86%
31%
2.3 m/s
63
11
73
November
15°C
11°C
13°C
93%
35%
2.4 m/s
28
1
81
December
12°C
9°C
11°C
93%
46%
2.6 m/s
12
0
74
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 Mill Valley weather by season
Year round, Mill Valley has days of about 12°C at their warmest in January, its coolest month, and 20°C in September, its warmest; the coolest hours of the day run from 9°C to 15°C through the year, and the average temperature over the year is 14°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.
Mill Valley weather in winterDecember to February
High 13°CLow 9°CRain 93%
Winter in Mill Valley has typical daily highs of about 13°C and lows of about 9°C, with a 93% chance of rain on a given day.
Mill Valley weather in springMarch to May
High 15°CLow 11°CRain 92%
Spring in Mill Valley has typical daily highs of about 15°C and lows of about 11°C, with a 92% chance of rain on a given day.
Mill Valley weather in summerJune to August
High 18°CLow 14°CRain 48%
Summer in Mill Valley has typical daily highs of about 18°C and lows of about 14°C, with a 48% chance of rain on a given day.
Mill Valley weather in autumnSeptember to November
High 18°CLow 13°CRain 82%
Autumn in Mill Valley has typical daily highs of about 18°C and lows of about 13°C, with a 82% chance of rain on a given day.
When is the rainy season in Mill Valley?
The rainy (wet) season in Mill Valley runs from October to May, peaking in January with a 94% chance of rain on a given day. The dry season is June to September; July is the driest month, at 45%.
What time of year is Mill Valley windiest?
Winds in Mill Valley are highest in June, averaging 3.6 m/s (13 km/h), and lightest in October, at 2.3 m/s (8 km/h). The prevailing wind is from the W.
What is the average temperature in Mill Valley year round?
The average temperature in Mill Valley over the whole year is 14°C. September is the hottest month, with highs of about 20°C; February is the coldest, with lows of about 9°C.