Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Vallejo enjoys a temperate climate with an average annual temperature of 57°F (14°C). Winters average 49°F in January while summers reach 66°F in July / relatively mild seasonal variation. The area gets 317 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 35.5 inches. Air quality is rated Good with a median AQI of 48. The city sits at an elevation of 102 feet.
Temperature
49°F Jan (9°C)66°F Jul (19°C)
Annual Average
57.1°F
6% above US avg
January Average
49°F (9°C)
July Average
66°F (19°C)
Sunny Days
317 days/yr
Geography
Elevation
102 ft (31 m)
Area
49.5 sq mi (128.3 km²)
Population Density
4,095/sq mi
Coordinates
38.1069°N, 122.2623°W
Timezone
America/Los_Angeles
County
Marin County County
Nearest Airport
Metro Oakland International (OAK) 27 miles away
Precipitation & Snow
Annual Rainfall35.5"
7% below US avg
Snowfall1.0"
Wettest Month (Jan)5.75"
Driest Month (Jul)0.04"
Air Quality
AQI Median
48.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively High
Risk Score
96.4 / 100
Social Vulnerability
24.7 / 100
Community Resilience
99.2 / 100
Hazard Breakdown
Tornado
Very Low
Earthquake
Relatively High
Wildfire
Relatively Moderate
Flood
Relatively High
Hail
Very Low
Strong Wind
Very Low
Heat Wave
Relatively Low
Winter Weather
Very Low
Lightning
Relatively Low
Drought
Relatively Low
Cold Wave
No Rating
Landslide
Relatively High
Coastal Flood
Very High
Tsunami
Relatively Moderate
Volcano
Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
4,551 earthquakes (M2.5+) recorded within 150 km since 1990.
Strongest on record: M6.0.
Aug 24, 2014
The 2014 South Napa, California Earthquake
M6.0
13 km
11 km
Apr 18, 1990
5 km NNW of Aromas, California
M5.4
141 km
5 km
Apr 18, 1990
4 km E of Interlaken, California
M5.1
138 km
7 km
Aug 10, 2016
20 km NNE of Upper Lake, California
M5.1
144 km
14 km
Jan 16, 1993
9 km E of Gilroy, California
M4.9
140 km
7 km
Apr 19, 1996
2 km E of Aromas, California
M4.9
147 km
5 km
Apr 18, 1990
4 km NNW of Aromas, California
M4.9
141 km
6 km
Sep 3, 2000
5 km WSW of Yountville, California
M4.9
33 km
9 km
May 14, 2002
5 km SSW of Gilroy, California
M4.9
140 km
7 km
Sep 4, 1995
13 km SW of Middletown, California
M4.8
77 km
7 km
May 12, 2006
7 km W of Cobb, California
M4.7
92 km
4 km
May 21, 1996
8 km ESE of East Foothills, California
M4.7
96 km
8 km
Apr 18, 1990
4 km N of Aromas, California
M4.7
142 km
4 km
Aug 11, 1993
14 km ESE of Alum Rock, California
M4.7
102 km
9 km
Jan 2, 2025
4 km NW of Cobb, CA
M4.7
93 km
1 km
Aug 18, 1999
0 km S of Bolinas, California
M4.6
43 km
8 km
Mar 24, 1991
1 km NNE of Interlaken, California
M4.6
136 km
15 km
Jan 11, 2000
6 km N of Geyserville, California
M4.6
93 km
6 km
Feb 18, 2004
4 km WNW of Cobb, California
M4.6
92 km
3 km
Jan 12, 2014
8 km W of Cobb, California
M4.5
92 km
2 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
69 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF2. Total: 4 injuries.
Date
Rating
Distance
Path
Fatalities
May 5, 1998
EF2
84 km
0.6 mi
0
Feb 7, 1978
EF2
97 km
1.9 mi
0
Jun 1, 1958
EF2
66 km
15.0 mi
0
Jan 11, 1951
EF2
83 km
5.7 mi
0
Mar 18, 2011
EF1
55 km
0.1 mi
0
Jan 23, 2010
EF1
49 km
1.6 mi
0
Mar 20, 2005
EF1
53 km
3.0 mi
0
Jan 27, 2005
EF1
94 km
0.5 mi
0
Dec 5, 1998
EF1
54 km
1.5 mi
0
May 5, 1998
EF1
82 km
0.3 mi
0
Dec 23, 1996
EF1
61 km
6.0 mi
0
Feb 22, 1996
EF1
64 km
1.0 mi
0
Dec 2, 1992
EF1
69 km
3.0 mi
0
Dec 2, 1992
EF1
65 km
7.5 mi
0
Dec 2, 1992
EF1
59 km
1.0 mi
0
Apr 19, 1988
EF1
98 km
0.2 mi
0
Feb 27, 1983
EF1
54 km
0.8 mi
0
Jan 14, 1980
EF1
77 km
0.3 mi
0
May 31, 1967
EF1
86 km
0.1 mi
0
Nov 10, 1964
EF1
66 km
1.0 mi
0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
5 tsunamis recorded within 500 km.
Highest wave on record: 4.5 m (15 ft).
Year
Location
Cause
Max Wave
Deaths
Distance
1868
N. CALIFORNIA
Eruption + Earthquake
4.5 m
30
47 km
1989
N. CALIFORNIA
Earthquake
1.0 m
62
124 km
1856
N. CALIFORNIA
Eruption + Earthquake
0.6 m
—
68 km
1906
N. CALIFORNIA
Eruption + Earthquake
0.1 m
—
50 km
1865
N. CALIFORNIA
Eruption + Earthquake
—
—
106 km
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
1 volcano within 200 km.
Closest: Clear Lake (106 km).
Name
Type
Elevation
Last Eruption
Distance
Clear Lake
Volcanic field
1,439 m (4,721 ft)
Unknown
106 km
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km.
Largest: SCU LIGHTNING COMPLEX (405,787 acres, 2020).
Year
Name
Acres Burned
Distance
2020
SCU LIGHTNING COMPLEX
405,787
96 km
2020
HENNESSEY
314,241
57 km
2015
ROCKY
96,125
91 km
2018
COUNTY
92,450
65 km
2019
KINCADE
77,780
77 km
2015
VALLEY
77,507
82 km
2020
GLASS
68,020
55 km
2017
NUNS
56,883
34 km
2020
WALLBRIDGE
55,194
86 km
2017
ATLAS
51,664
29 km
2004
RUMSEY
39,335
72 km
1999
SIXTEEN
37,162
78 km
2017
TUBBS
36,981
63 km
1988
MILLER
35,750
39 km
2017
POCKET
18,691
91 km
2024
CORRAL
16,138
88 km
2006
ZAM ASSIST
14,404
78 km
2004
GEYSERS
12,075
81 km
2009
CORRAL
12,006
89 km
1995
VISION
11,931
53 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
49°F (9°C)
5.8 in
Wettest
February
52°F (11°C)
4.9 in
March
54°F (12°C)
3.9 in
April
58°F (14°C)
1.4 in
May
63°F (17°C)
0.6 in
June
68°F (20°C)
0.2 in
July
66°F (19°C)
0.0 in
Driest
August
71°F (21°C)
0.1 in
Warmest
September
69°F (20°C)
0.3 in
October
63°F (17°C)
1.5 in
November
54°F (12°C)
3.9 in
December
47°F (8°C)
4.2 in
Coldest
Vallejo has a seasonal temperature swing of 23°F / from 47°F in December to 71°F in August. Total annual precipitation is 26.7 inches, with January being the wettest month (5.8") and July the driest (0.0").