Annual mean 11°C · wettest around January · prevailing wind SW
Warmest
22.1 °C
Coldest
6.0 °C
Wettest
24%
Windiest
3.7 m/s
Prevailing
SW
3.1 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 Vashon over the whole year is 11°C. July is the hottest month, with highs of about 23°C; February is the coldest, with lows of about 4°C. The rainy (wet) season in Vashon runs from October to April, peaking in January with a 28% chance of rain on a given day. The dry season is May to September; July is the driest month, at 4%. Winds in Vashon are highest in February, averaging 2.9 m/s (10 km/h), and lightest in August, at 2.3 m/s (8 km/h). The prevailing wind is from the SW. The clearest skies in Vashon come in July, when the sky is typically 38% covered; December is the cloudiest month, at 75%.
Month by month Vashon 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
7°C
4°C
3°C
28%
74%
2.5 m/s
0
0
25
February
7°C
4°C
3°C
23%
74%
2.9 m/s
0
0
23
March
10°C
5°C
6°C
22%
66%
2.8 m/s
3
0
42
April
13°C
7°C
9°C
19%
60%
2.9 m/s
12
0
65
May
17°C
10°C
13°C
12%
58%
2.6 m/s
39
3
84
June
20°C
13°C
17°C
11%
55%
2.7 m/s
63
7
83
July
23°C
15°C
20°C
4%
38%
2.4 m/s
88
19
72
August
23°C
15°C
21°C
6%
41%
2.3 m/s
85
23
68
September
19°C
13°C
17°C
13%
53%
2.3 m/s
73
6
84
October
14°C
9°C
11°C
21%
60%
2.4 m/s
23
0
79
November
9°C
6°C
6°C
27%
71%
2.7 m/s
3
0
44
December
7°C
5°C
3°C
26%
75%
2.6 m/s
0
0
21
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 Vashon weather by season
Year round, Vashon has days of about 7°C at their warmest in December, its coolest month, and 23°C in July, its warmest; the coolest hours of the day run from 4°C to 15°C through the year, and the average temperature over the year is 11°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.
Vashon weather in winterDecember to February
High 7°CLow 4°CRain 26%
Winter in Vashon has typical daily highs of about 7°C and lows of about 4°C, with a 26% chance of rain on a given day.
Vashon weather in springMarch to May
High 13°CLow 8°CRain 18%
Spring in Vashon has typical daily highs of about 13°C and lows of about 8°C, with a 18% chance of rain on a given day.
Vashon weather in summerJune to August
High 22°CLow 14°CRain 7%
Summer in Vashon has typical daily highs of about 22°C and lows of about 14°C, with a 7% chance of rain on a given day.
Vashon weather in autumnSeptember to November
High 14°CLow 9°CRain 21%
Autumn in Vashon has typical daily highs of about 14°C and lows of about 9°C, with a 21% chance of rain on a given day.
When is the rainy season in Vashon?
The rainy (wet) season in Vashon runs from October to April, peaking in January with a 28% chance of rain on a given day. The dry season is May to September; July is the driest month, at 4%.
What time of year is Vashon windiest?
Winds in Vashon are highest in February, averaging 2.9 m/s (10 km/h), and lightest in August, at 2.3 m/s (8 km/h). The prevailing wind is from the SW.
What is the average temperature in Vashon year round?
The average temperature in Vashon over the whole year is 11°C. July is the hottest month, with highs of about 23°C; February is the coldest, with lows of about 4°C.