Hartley, CA
Full City Profile · California · Solano County County
3.5
/5.0
B+
Good
1,966
Population
304/sq mi density
$120,354
Median Income
$60,227 per capita
$864,100
Home Value
$603,548 Zillow
$1,115
Median Rent
31.5% income on rent
62°F
Avg Temperature
B+
Overall
3.5 / 5.0
Good overall score based on economy, affordability, safety and education
A+
Economy
5.0 / 5.0
$120,354 median income, 0.1% unemployment
C+
Affordability
2.6 / 5.0
$864,100 home value, $1,115/mo rent
C+
Education
2.9 / 5.0
24.0% bachelor's degree or higher
Hartley 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. Annual precipitation totals 24.8 inches. The area receives 0.0 inches of snow annually. Air quality is rated Good with a median AQI of 39.
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) |
Geography
| Elevation | 130 ft (40 m) |
| Area | 6.5 sq mi (16.8 km²) |
| Population Density | 304/sq mi |
| Coordinates | 38.4204°N, 121.9508°W |
| Timezone | America/Los_Angeles |
| County | Solano County County |
| Nearest Airport | Sacramento International (SMF) 27 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 39.0 |
| Rating | Good |
| Good Days % | 76.2% |
| Unhealthy Days | 1 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0361 ppm |
| NO₂ (Nitrogen Dioxide) | 9.0 ppb |
| SO₂ (Sulfur Dioxide) | 0.34 ppb |
| CO (Carbon Monoxide) | 0.39 ppm |
| PM2.5 (Fine Particles) | 6.2 μg/m³ |
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)
Tsunami History
4 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 | 81 km |
| 1856 | N. CALIFORNIA | Eruption + Earthquake | 0.6 m | - | 107 km |
| 1906 | N. CALIFORNIA | Eruption + Earthquake | 0.1 m | - | 93 km |
| 1865 | N. CALIFORNIA | Eruption + Earthquake | - | - | 136 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Nearby Volcanoes
1 volcano within 200 km. Closest: Clear Lake (94 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Clear Lake | Volcanic field | 1,439 m (4,721 ft) | Unknown | 94 km |
Source: Smithsonian Institution Global Volcanism Program (GVP). Sorted by distance.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 48°F (9°C) | 5.3 in | Wettest |
| February | 52°F (11°C) | 5.1 in | |
| March | 55°F (13°C) | 3.7 in | |
| April | 59°F (15°C) | 1.3 in | |
| May | 66°F (19°C) | 0.8 in | |
| June | 73°F (23°C) | 0.2 in | |
| July | 77°F (25°C) | 0.0 in | Warmest, Driest |
| August | 76°F (24°C) | 0.0 in | |
| September | 73°F (23°C) | 0.1 in | |
| October | 65°F (18°C) | 1.1 in | |
| November | 54°F (12°C) | 2.3 in | |
| December | 48°F (9°C) | 5.1 in | Coldest |
Hartley has a seasonal temperature swing of 30°F / from 48°F in December to 77°F in July. Total annual precipitation is 24.8 inches, with January being the wettest month (5.3") and July the driest (0.0").