Weather & Climate in San Carlos, CA

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

San Carlos 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 100 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	100 ft (30 m)
Area	5.5 sq mi (14.3 km²)
Population Density	5,508/sq mi
Coordinates	37.4990°N, 122.2676°W
Timezone	America/Los_Angeles
County	San Mateo County County
Nearest Airport	San Francisco International (SFO) 10 miles away

Precipitation & Snow

Annual Rainfall 19.0"

50% below US avg

Snowfall 0.0"

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

4,504 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	80 km	11 km
Apr 18, 1990	5 km NNW of Aromas, California	M5.4	83 km	5 km
Apr 18, 1990	4 km E of Interlaken, California	M5.1	79 km	7 km
Aug 12, 1998	10 km SW of Ridgemark, California	M5.1	109 km	9 km
Jan 16, 1993	9 km E of Gilroy, California	M4.9	89 km	7 km
May 14, 2002	5 km SSW of Gilroy, California	M4.9	84 km	7 km
Apr 18, 1990	4 km NNW of Aromas, California	M4.9	83 km	6 km
Apr 23, 1995	22 km NNE of Soledad, California	M4.9	138 km	7 km
Apr 19, 1996	2 km E of Aromas, California	M4.9	90 km	5 km
Sep 3, 2000	5 km WSW of Yountville, California	M4.9	99 km	9 km
Sep 4, 1995	13 km SW of Middletown, California	M4.8	138 km	7 km
Apr 18, 1990	4 km N of Aromas, California	M4.7	84 km	4 km
May 21, 1996	8 km ESE of East Foothills, California	M4.7	51 km	8 km
Aug 11, 1993	14 km ESE of Alum Rock, California	M4.7	56 km	9 km
Aug 27, 2011	21 km NE of Soledad, California	M4.6	140 km	8 km
Mar 24, 1991	1 km NNE of Interlaken, California	M4.6	76 km	15 km
Aug 18, 1999	0 km S of Bolinas, California	M4.6	59 km	8 km
Sep 19, 2023	15 km SW of Westley, CA	M4.5	86 km	4 km
Aug 3, 2006	5 km W of Glen Ellen, California	M4.5	100 km	9 km
Jan 12, 2011	9 km SSE of San Juan Bautista, California	M4.5	106 km	8 km

Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.

Tornado History

42 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2. Total: 9 injuries.

Date	Rating	Distance	Path	Fatalities
May 5, 1998	EF2	25 km	0.6 mi	0
Jan 11, 1951	EF2	19 km	5.7 mi	0
Dec 14, 2024	EF1	54 km	0.3 mi	0
Jan 23, 2010	EF1	64 km	1.6 mi	0
Mar 20, 2005	EF1	22 km	3.0 mi	0
Dec 20, 2001	EF1	73 km	0.5 mi	0
May 5, 1998	EF1	19 km	0.3 mi	0
Jan 14, 1980	EF1	34 km	0.3 mi	0
May 31, 1967	EF1	100 km	0.1 mi	0
Apr 1, 1965	EF1	71 km	0.1 mi	0
Apr 1, 1958	EF1	15 km	0.2 mi	0
Jan 6, 2019	EF0	64 km	0.5 mi	0
Jan 6, 2019	EF0	63 km	0.1 mi	0
Dec 22, 2012	EF0	79 km	1.1 mi	0
Apr 11, 2012	EF0	92 km	0.3 mi	0
Apr 7, 2011	EF0	84 km	0.1 mi	0
Apr 14, 2007	EF0	81 km	0.2 mi	0
Dec 26, 2005	EF0	79 km	0.3 mi	0
Apr 8, 2005	EF0	92 km	1.5 mi	0
Dec 5, 1998	EF0	62 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	27 km
1989	N. CALIFORNIA	Earthquake	1.0 m	62	62 km
1856	N. CALIFORNIA	Eruption + Earthquake	0.6 m	—	3 km
1906	N. CALIFORNIA	Eruption + Earthquake	0.1 m	—	30 km
1865	N. CALIFORNIA	Eruption + Earthquake	—	—	47 km

Source: NOAA/NCEI Historical Tsunami Database.

Nearby Volcanoes

1 volcano within 200 km. Closest: Clear Lake (169 km).

Name	Type	Elevation	Last Eruption	Distance
Clear Lake	Volcanic field	1,439 m (4,721 ft)	Unknown	169 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	68 km
2020	CZU AUG LIGHTNING	85,894	40 km
2017	NUNS	56,883	97 km
2017	ATLAS	51,664	96 km
2007	LICK	47,424	80 km
2006	CANYON	36,851	83 km
2003	ANNIE	17,383	95 km
2024	CORRAL	16,138	73 km
2009	CORRAL	12,006	70 km
1995	VISION	11,931	80 km
1985	LEXINGTON	11,550	50 km
2009	LOCKHEED	8,287	47 km
2003	BIRD	7,727	82 km
1984	SITE 300 3	6,911	72 km
2005	TESLA	6,638	65 km
2003	DEL PUERTO	6,441	77 km
2006	MIDWAY	6,243	68 km
2020	CREWS	5,802	90 km
2003	DEVIL	4,975	61 km
2020	WOODWARD	4,952	76 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

San Carlos 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").

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