Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Atherton enjoys a temperate climate with an average annual temperature of 59°F (15°C). Winters average 50°F in January while summers reach 69°F in July / relatively mild seasonal variation. The area gets 330 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 19.0 inches (drier than the 38-inch national average). Air quality is rated Good with a median AQI of 48. The city sits at an elevation of 66 feet.
Temperature
50°F Jan (10°C)69°F Jul (20°C)
Annual Average
59.4°F
10% above US avg
January Average
50°F (10°C)
July Average
69°F (20°C)
Sunny Days
330 days/yr
Geography
Elevation
66 ft (20 m)
Area
5.1 sq mi (13.1 km²)
Population Density
1,399/sq mi
Coordinates
37.4571°N, 122.2011°W
Timezone
America/Los_Angeles
County
San Mateo County County
Nearest Airport
San Francisco International (SFO) 15 miles away
Precipitation & Snow
Annual Rainfall19.0"
50% below US avg
Snowfall0.0"
Wettest Month (Jan)5.43"
Driest Month (Jul)0.08"
Air Quality
AQI Median
48.0
Rating
Good
Natural Hazard Risk
Overall Risk
Relatively High
Risk Score
99.2 / 100
Social Vulnerability
20.5 / 100
Community Resilience
97.6 / 100
Hazard Breakdown
Tornado
Relatively Low
Earthquake
Relatively High
Wildfire
Relatively Moderate
Flood
Relatively High
Hail
Very Low
Strong Wind
Relatively Low
Heat Wave
Relatively Moderate
Winter Weather
Very Low
Lightning
Relatively Moderate
Drought
Relatively High
Cold Wave
No Rating
Landslide
Relatively High
Coastal Flood
Relatively High
Tsunami
Relatively Moderate
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
4,041 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
85 km
11 km
Apr 18, 1990
5 km NNW of Aromas, California
M5.4
76 km
5 km
Aug 12, 1998
10 km SW of Ridgemark, California
M5.1
102 km
9 km
Apr 18, 1990
4 km E of Interlaken, California
M5.1
72 km
7 km
Jan 16, 1993
9 km E of Gilroy, California
M4.9
82 km
7 km
Sep 3, 2000
5 km WSW of Yountville, California
M4.9
104 km
9 km
May 14, 2002
5 km SSW of Gilroy, California
M4.9
76 km
7 km
Apr 18, 1990
4 km NNW of Aromas, California
M4.9
76 km
6 km
Apr 19, 1996
2 km E of Aromas, California
M4.9
82 km
5 km
Apr 23, 1995
22 km NNE of Soledad, California
M4.9
130 km
7 km
Sep 4, 1995
13 km SW of Middletown, California
M4.8
144 km
7 km
Apr 18, 1990
4 km N of Aromas, California
M4.7
77 km
4 km
May 21, 1996
8 km ESE of East Foothills, California
M4.7
44 km
8 km
Aug 11, 1993
14 km ESE of Alum Rock, California
M4.7
49 km
9 km
Aug 27, 2011
21 km NE of Soledad, California
M4.6
133 km
8 km
Aug 18, 1999
0 km S of Bolinas, California
M4.6
66 km
8 km
Mar 24, 1991
1 km NNE of Interlaken, California
M4.6
69 km
15 km
Sep 19, 2023
15 km SW of Westley, CA
M4.5
80 km
4 km
Jan 12, 2011
9 km SSE of San Juan Bautista, California
M4.5
99 km
8 km
Aug 3, 2006
5 km W of Glen Ellen, California
M4.5
106 km
9 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Tornado History
46 tornadoes (EF0+) recorded within 100 km since 1950.
Strongest on record: EF2. Total: 9 injuries.
Date
Rating
Distance
Path
Fatalities
May 5, 1998
EF2
18 km
0.6 mi
0
Mar 11, 1985
EF2
98 km
0.5 mi
0
Jan 11, 1951
EF2
12 km
5.7 mi
0
Dec 14, 2024
EF1
48 km
0.3 mi
0
Jan 23, 2010
EF1
64 km
1.6 mi
0
Mar 20, 2005
EF1
29 km
3.0 mi
0
Dec 20, 2001
EF1
66 km
0.5 mi
0
May 5, 1998
EF1
11 km
0.3 mi
0
Dec 6, 1992
EF1
100 km
1.0 mi
0
Jan 14, 1980
EF1
28 km
0.3 mi
0
May 31, 1967
EF1
98 km
0.1 mi
0
Apr 1, 1965
EF1
64 km
0.1 mi
0
Apr 1, 1958
EF1
22 km
0.2 mi
0
Jan 6, 2019
EF0
57 km
0.1 mi
0
Jan 6, 2019
EF0
58 km
0.5 mi
0
Jan 6, 2016
EF0
93 km
0.6 mi
0
Dec 22, 2012
EF0
72 km
1.1 mi
0
Apr 11, 2012
EF0
90 km
0.3 mi
0
Apr 7, 2011
EF0
88 km
0.1 mi
0
Apr 14, 2007
EF0
74 km
0.2 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
28 km
1989
N. CALIFORNIA
Earthquake
1.0 m
62
55 km
1856
N. CALIFORNIA
Eruption + Earthquake
0.6 m
—
10 km
1906
N. CALIFORNIA
Eruption + Earthquake
0.1 m
—
38 km
1865
N. CALIFORNIA
Eruption + Earthquake
—
—
39 km
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
1 volcano within 200 km.
Closest: Clear Lake (175 km).
Name
Type
Elevation
Last Eruption
Distance
Clear Lake
Volcanic field
1,439 m (4,721 ft)
Unknown
175 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
62 km
2020
CZU AUG LIGHTNING
85,894
35 km
2007
LICK
47,424
73 km
2006
CANYON
36,851
76 km
2003
ANNIE
17,383
88 km
2024
CORRAL
16,138
68 km
2009
CORRAL
12,006
65 km
1995
VISION
11,931
88 km
1985
LEXINGTON
11,550
43 km
2009
LOCKHEED
8,287
42 km
2003
BIRD
7,727
77 km
1984
SITE 300 3
6,911
68 km
2005
TESLA
6,638
61 km
2003
DEL PUERTO
6,441
71 km
2006
MIDWAY
6,243
64 km
2020
CREWS
5,802
82 km
2003
DEVIL
4,975
56 km
2020
WOODWARD
4,952
84 km
2003
JUMP
4,817
61 km
2016
LOMA
4,380
51 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
Month
Avg Temperature
Precipitation
Summary
January
50°F (10°C)
5.4 in
Wettest
February
51°F (11°C)
4.4 in
March
52°F (11°C)
4.3 in
April
55°F (13°C)
1.9 in
May
58°F (15°C)
0.5 in
June
62°F (17°C)
0.2 in
July
69°F (20°C)
0.1 in
Warmest, Driest
August
66°F (19°C)
0.1 in
September
65°F (18°C)
0.4 in
October
61°F (16°C)
1.5 in
November
54°F (12°C)
3.9 in
December
49°F (9°C)
4.3 in
Coldest
Atherton has a seasonal temperature swing of 20°F / from 49°F in December to 69°F in July. Total annual precipitation is 26.9 inches, with January being the wettest month (5.4") and July the driest (0.1").