Annual mean 15°C · wettest around March · prevailing wind NW
Warmest
23.5 °C
Coldest
12.9 °C
Wettest
27%
Windiest
5.0 m/s
Prevailing
NW
3.8 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 Sunnyvale over the whole year is 15°C. September is the hottest month, with highs of about 23°C; February is the coldest, with lows of about 8°C. The rainy (wet) season in Sunnyvale runs from November to April, peaking in March with a 28% chance of rain on a given day. The dry season is May to October; June is the driest month, at 3%. Winds in Sunnyvale are highest in June, averaging 3.6 m/s (13 km/h), and lightest in November, at 1.9 m/s (7 km/h). The prevailing wind is from the NW. The clearest skies in Sunnyvale come in October, when the sky is typically 28% covered; January is the cloudiest month, at 49%.
Month by month Sunnyvale 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
14°C
8°C
11°C
27%
49%
2.3 m/s
16
0
80
February
14°C
8°C
11°C
26%
38%
2.6 m/s
25
0
77
March
15°C
9°C
12°C
28%
47%
2.9 m/s
28
0
81
April
18°C
10°C
14°C
17%
38%
3.2 m/s
48
3
84
May
19°C
12°C
16°C
11%
40%
3.5 m/s
62
6
82
June
22°C
14°C
19°C
3%
29%
3.6 m/s
74
16
72
July
22°C
15°C
20°C
4%
32%
3.4 m/s
80
20
69
August
23°C
16°C
21°C
5%
35%
3.2 m/s
83
24
63
September
23°C
15°C
21°C
5%
31%
2.8 m/s
80
22
65
October
21°C
13°C
19°C
12%
28%
2.3 m/s
78
13
75
November
17°C
9°C
14°C
18%
33%
1.9 m/s
49
1
88
December
14°C
8°C
11°C
25%
41%
2.0 m/s
16
0
81
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 Sunnyvale weather by season
Year round, Sunnyvale has days of about 14°C at their warmest in January, its coolest month, and 23°C in September, its warmest; the coolest hours of the day run from 8°C to 16°C through the year, and the average temperature over the year is 15°C around the clock. Rain is most likely around March and least likely around June. 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.
Sunnyvale weather in winterDecember to February
High 14°CLow 8°CRain 26%
Winter in Sunnyvale has typical daily highs of about 14°C and lows of about 8°C, with a 26% chance of rain on a given day.
Sunnyvale weather in springMarch to May
High 17°CLow 10°CRain 19%
Spring in Sunnyvale has typical daily highs of about 17°C and lows of about 10°C, with a 19% chance of rain on a given day.
Sunnyvale weather in summerJune to August
High 22°CLow 15°CRain 4%
Summer in Sunnyvale has typical daily highs of about 22°C and lows of about 15°C, with a 4% chance of rain on a given day.
Sunnyvale weather in autumnSeptember to November
High 20°CLow 12°CRain 12%
Autumn in Sunnyvale has typical daily highs of about 20°C and lows of about 12°C, with a 12% chance of rain on a given day.
When is the rainy season in Sunnyvale?
The rainy (wet) season in Sunnyvale runs from November to April, peaking in March with a 28% chance of rain on a given day. The dry season is May to October; June is the driest month, at 3%.
What time of year is Sunnyvale windiest?
Winds in Sunnyvale are highest in June, averaging 3.6 m/s (13 km/h), and lightest in November, at 1.9 m/s (7 km/h). The prevailing wind is from the NW.
What is the average temperature in Sunnyvale year round?
The average temperature in Sunnyvale over the whole year is 15°C. September is the hottest month, with highs of about 23°C; February is the coldest, with lows of about 8°C.