Weather & Climate in Rio Vista, CA

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

Rio Vista enjoys a temperate climate with an average annual temperature of 62°F (17°C). Winters average 48°F in January while summers reach 77°F in July. The area gets 326 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 24.8 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 38 feet.

Temperature

48°F Jan (9°C) 77°F Jul (25°C)

Annual Average	62.1°F
	15% above US avg
January Average	48°F (9°C)
July Average	77°F (25°C)
Sunny Days	326 days/yr

Geography

Elevation	38 ft (12 m)
Area	7.0 sq mi (18.2 km²)
Population Density	1,515/sq mi
Coordinates	38.1767°N, 121.7034°W
Timezone	America/Los_Angeles
County	Solano County County
Nearest Airport	Sacramento International (SMF) 36 miles away

Precipitation & Snow

Annual Rainfall 24.8"

35% below US avg

Wettest Month (Jan) 3.94"

Driest Month (Jul) 0.04"

Air Quality

AQI Median	48.0
Rating	Good

Natural Hazard Risk

Overall Risk	Relatively High
Risk Score	97.0 / 100
Social Vulnerability	25.2 / 100
Community Resilience	71.8 / 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 Low
Winter Weather	Very Low
Lightning	Relatively Moderate
Drought	Relatively High
Cold Wave	No Rating
Landslide	Relatively High
Coastal Flood	Relatively High
Tsunami	Very Low
Volcano	Very Low
Avalanche	Very Low

Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

4,647 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	53 km	11 km
Apr 18, 1990	5 km NNW of Aromas, California	M5.4	138 km	5 km
Apr 18, 1990	4 km E of Interlaken, California	M5.1	135 km	7 km
Jan 16, 1993	9 km E of Gilroy, California	M4.9	131 km	7 km
Apr 18, 1990	4 km NNW of Aromas, California	M4.9	139 km	6 km
Sep 3, 2000	5 km WSW of Yountville, California	M4.9	66 km	9 km
Apr 19, 1996	2 km E of Aromas, California	M4.9	144 km	5 km
May 14, 2002	5 km SSW of Gilroy, California	M4.9	135 km	7 km
Sep 4, 1995	13 km SW of Middletown, California	M4.8	107 km	7 km
May 12, 2006	7 km W of Cobb, California	M4.7	120 km	4 km
May 21, 1996	8 km ESE of East Foothills, California	M4.7	91 km	8 km
Apr 18, 1990	4 km N of Aromas, California	M4.7	139 km	4 km
Aug 11, 1993	14 km ESE of Alum Rock, California	M4.7	96 km	9 km
Jan 2, 2025	4 km NW of Cobb, CA	M4.7	118 km	1 km
Mar 24, 1991	1 km NNE of Interlaken, California	M4.6	135 km	15 km
Aug 18, 1999	0 km S of Bolinas, California	M4.6	91 km	8 km
Jan 11, 2000	6 km N of Geyserville, California	M4.6	124 km	6 km
Feb 18, 2004	4 km WNW of Cobb, California	M4.6	118 km	3 km
Sep 19, 2023	15 km SW of Westley, CA	M4.5	90 km	4 km
Jan 12, 2014	8 km W of Cobb, California	M4.5	120 km	2 km

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

Tornado History

84 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2. Total: 4 injuries.

Date	Rating	Distance	Path	Fatalities
May 5, 1998	EF2	94 km	0.6 mi	0
Feb 7, 1978	EF2	62 km	1.9 mi	0
Apr 27, 1953	EF2	85 km	0.1 mi	0
Jan 11, 1951	EF2	97 km	5.7 mi	0
Jan 10, 2023	EF1	83 km	0.4 mi	0
Dec 24, 2015	EF1	78 km	6.2 mi	0
Oct 22, 2012	EF1	99 km	2.0 mi	0
Mar 18, 2011	EF1	93 km	0.1 mi	0
Jan 23, 2010	EF1	30 km	1.6 mi	0
Apr 14, 2006	EF1	85 km	0.5 mi	0
Mar 20, 2005	EF1	86 km	3.0 mi	0
Dec 5, 1998	EF1	92 km	1.5 mi	0
May 5, 1998	EF1	96 km	0.3 mi	0
Dec 12, 1996	EF1	87 km	0.6 mi	0
Feb 22, 1996	EF1	99 km	1.0 mi	0
Apr 19, 1988	EF1	73 km	1.0 mi	0
Apr 19, 1988	EF1	48 km	0.2 mi	0
Mar 22, 1983	EF1	68 km	2.0 mi	0
Feb 27, 1983	EF1	92 km	0.8 mi	0
Jan 14, 1980	EF1	79 km	0.3 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	63 km
1989	N. CALIFORNIA	Earthquake	1.0 m	62	128 km
1856	N. CALIFORNIA	Eruption + Earthquake	0.6 m	-	92 km
1906	N. CALIFORNIA	Eruption + Earthquake	0.1 m	-	88 km
1865	N. CALIFORNIA	Eruption + Earthquake	-	-	110 km

Source: NOAA/NCEI Historical Tsunami Database.

Nearby Volcanoes

1 volcano within 200 km. Closest: Clear Lake (128 km).

Name	Type	Elevation	Last Eruption	Distance
Clear Lake	Volcanic field	1,439 m (4,721 ft)	Unknown	128 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	78 km
2020	HENNESSEY	314,241	71 km
2018	COUNTY	92,450	69 km
2015	BUTTE	72,894	98 km
2020	GLASS	68,020	85 km
2017	NUNS	56,883	72 km
2017	ATLAS	51,664	51 km
2004	RUMSEY	39,335	81 km
1999	SIXTEEN	37,162	88 km
2017	TUBBS	36,981	96 km
2006	CANYON	36,851	96 km
1988	MILLER	35,750	44 km
2024	CORRAL	16,138	64 km
2006	ZAM ASSIST	14,404	67 km
2018	WAVERLY	12,238	78 km
2009	CORRAL	12,006	68 km
1996	SCOTT	8,828	72 km
2015	WRAGG	8,455	47 km
2003	BIRD	7,727	77 km
2014	MONTICELLO	6,984	51 km

Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month	Avg Temperature	Precipitation	Summary
January	48°F (9°C)	3.9 in	Wettest
February	51°F (10°C)	3.3 in
March	54°F (12°C)	2.5 in
April	59°F (15°C)	0.9 in
May	65°F (18°C)	0.4 in
June	70°F (21°C)	0.1 in
July	77°F (25°C)	0.0 in	Warmest, Driest
August	72°F (22°C)	0.1 in
September	70°F (21°C)	0.3 in
October	64°F (18°C)	0.9 in
November	53°F (12°C)	2.4 in
December	46°F (8°C)	2.6 in	Coldest

Rio Vista has a seasonal temperature swing of 32°F / from 46°F in December to 77°F in July. Total annual precipitation is 17.6 inches, with January being the wettest month (3.9") and July the driest (0.0").

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