Weather

Sonoma County's weather is world-renowned for its microclimates and its ability to produce great grapes for wines. The western border of Sonoma County is comprised of the Pacific Ocean coastline, which brings a welcome cooling during summer nights and some early morning fog in some areas. The inner valley areas of Sonoma County are usually warmer than the areas along the coast.

The graph below outlines the average annual weather pattern in Santa Rosa, which is located in the middle of Sonoma County.


Averages

Jan

Feb

Mar

Apr

May

June

Jul

Aug

Sept

Oct

Nov

Dec

Daily Maximum

57

63

66

70

75

81

84

84

84

78

66

58

Daily Minimum

36

39

39

41

45

49

51

51

50

45

40

37

Monthly Precipitation

7.2

4.7

3.4

2.3

0.5

0.3

0.1

0.2

0.4

1.9

3.7

5.5

Days w/> .01 Precipitation

11

10

10

6

3

1

1

1

1

3

7

10

Days w/Snow, Ice Pellets > .01

0

0

0

0

0

0

0

0

0

0

0

0

Days with Thunderstorms

0

1

0

0

0

0

0

0

1

0

0

0

Days with Fog 1/4 mile or less

10

5

2

1

0

0

0

0

0

1

6

10

Clear Days

6

8

10

12

18

22

27

26

23

19

10

8

Partially Cloudy Days

6

7

8

10

8

6

3

4

4

6

7

6

Cloudy Days

19

13

12

8

5

2

1

1

2

6

13

17