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San Miguel CDP (Contra Costa County), CA
Full City Profile · California · San Mateo County County
3.4
/5.0
B
Good
3,991
Population
3,801/sq mi density
$224,219
Median Income
$106,023 per capita
$1,627,300
Home Value
$1,024,673 Zillow
$2,458
Median Rent
36.7% income on rent
62°F
Avg Temperature
330 sunny days/yr
110
Violent Crime/100K
3,610 property/100K
B
Overall
3.4 / 5.0
Good overall score based on economy, affordability, safety and education
A+
Economy
5.0 / 5.0
$224,219 median income, 1.9% unemployment
C+
Affordability
2.6 / 5.0
$1,627,300 home value, $2,458/mo rent
F
Safety
1.0 / 5.0
110 violent crimes/100K
A+
Education
5.0 / 5.0
67.5% bachelor's degree or higher
San Miguel CDP (Contra Costa County) enjoys a temperate climate with an average annual temperature of 62°F (17°C). Winters average 50°F in January while summers reach 73°F in July. The area gets 330 sunny days per year. Annual precipitation totals 17.7 inches. The area receives 0.0 inches of snow annually. Air quality is rated Good with a median AQI of 48.
Temperature
50°F Jan (10°C)
73°F Jul (23°C)
| Annual Average | 62.4°F |
| 16% above US avg | |
| January Average | 50°F (10°C) |
| July Average | 73°F (23°C) |
| Sunny Days | 330 days/yr |
Geography
| Elevation | 262 ft (80 m) |
| Area | 1.1 sq mi (2.7 km²) |
| Population Density | 3,801/sq mi |
| Coordinates | 37.8867°N, 122.0368°W |
| Timezone | America/Los_Angeles |
| County | San Mateo County County |
| Nearest Airport | Metro Oakland International (OAK) 15 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 48.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0332 ppm |
| NO₂ (Nitrogen Dioxide) | 12.1 ppb |
| CO (Carbon Monoxide) | 0.34 ppm |
| PM2.5 (Fine Particles) | 4.5 μg/m³ |
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)
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 | 22 km |
| 1989 | N. CALIFORNIA | Earthquake | 1.0 m | 62 | 96 km |
| 1856 | N. CALIFORNIA | Eruption + Earthquake | 0.6 m | — | 49 km |
| 1906 | N. CALIFORNIA | Eruption + Earthquake | 0.1 m | — | 46 km |
| 1865 | N. CALIFORNIA | Eruption + Earthquake | — | — | 77 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Nearby Volcanoes
1 volcano within 200 km. Closest: Clear Lake (136 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Clear Lake | Volcanic field | 1,439 m (4,721 ft) | Unknown | 136 km |
Source: Smithsonian Institution Global Volcanism Program (GVP). Sorted by distance.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 50°F (10°C) | 4.7 in | Wettest |
| February | 51°F (11°C) | 3.9 in | |
| March | 54°F (12°C) | 3.2 in | |
| April | 57°F (14°C) | 1.3 in | |
| May | 62°F (17°C) | 0.5 in | |
| June | 67°F (19°C) | 0.1 in | |
| July | 73°F (23°C) | 0.0 in | Warmest, Driest |
| August | 70°F (21°C) | 0.1 in | |
| September | 68°F (20°C) | 0.3 in | |
| October | 63°F (17°C) | 1.2 in | |
| November | 54°F (12°C) | 3.2 in | |
| December | 48°F (9°C) | 3.3 in | Coldest |
San Miguel CDP (Contra Costa County) has a seasonal temperature swing of 26°F / from 48°F in December to 73°F in July. Total annual precipitation is 21.8 inches, with January being the wettest month (4.7") and July the driest (0.0").