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San Diego County Climate

San Diego County, California

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec62.6°AVG °F

Avg Annual Temp

62.6°F

Annual Precip

14.0"

Annual Snowfall

3.8"

Extreme Heat Days

43

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
2.8"
3.3"
2.2"
1.0"
0.4"
0.1"
0.2"
0.1"
0.2"
0.6"
1.1"
2.1"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

10b

Minimum winter temperature range for plant survival

Growing Degree Days

4,851

Excellent for heat-loving crops

Last spring frost (32°F): 04/18
First fall frost (32°F): 12/11

Seasonal Overview

Comfort ZoneSpring56°64°3.6"Summer68°75°0.4"Fall58°72°2.0"Winter53°54°8.1"20°40°60°80°100°

National Comparison

Warmer than 80% of US counties
Wetter than 6% of US counties
More seasonal variation than 1% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: San Diego County

Climate Verdict

San Diego County has a warm, averaging 62.6°F year-round, arid conditions receiving just 14.0 inches of precipitation annually, occasional hot days — 42.51428571428571 per year above 90°F, light snow averaging 3.8 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are mild, with January temperatures averaging 53.5°F. summers are warm — July averages 73.3°F. The climate is remarkably stable year-round, with only a 20°F difference between January and July. December is typically the coldest month and August the warmest.

Outdoor & Gardening Guidance

The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.

Regional Context

San Diego County is 4.0°F warmer than the California statewide average of 58.7°F, it is also noticeably drier, receiving 11.8 inches less precipitation than the state average, the county experiences 16.156639248648162 fewer extreme heat days than the state average.

Climate Profile

About San Diego County Weather

Mild Mediterranean comfort in San Diego

San Diego County averages 62.6°F annually, offering a temperate climate warmer than the national median. It receives 14 inches of rain, characteristic of a semi-arid coastal region.

Consistently warmer than state average

At 62.6°F, the county is warmer than the California average of 58.7°F. Its rainfall is roughly half of the state average, reflecting the dry nature of Southern California.

More moderate than the interior

San Diego is much cooler than neighboring Riverside County, which averages 69.5°F. It also receives nearly double the annual rainfall of its inland neighbors to the north and east.

Stable temperatures year-round

The county only experiences 43 extreme heat days, far fewer than the 140 seen in Riverside. January averages 53.5°F and July averages 73.3°F, showing very little seasonal variation.

Focus on sun and drought

With 43 days of heat over 90°F, moderate cooling is usually sufficient. Water-wise landscaping is critical given the modest 14 inches of annual precipitation.

Frequently Asked Questions

What is the average temperature in San Diego County?
The average annual temperature in San Diego County, CA is 62.6°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does San Diego County get?
San Diego County receives an average of 14.0 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in San Diego County?
Yes, San Diego County receives an average of 3.8 inches of snowfall per year according to NOAA climate normals.
How hot does San Diego County get in summer?
The average summer temperature (June-August) in San Diego County is 72.0°F. The county experiences an average of 43 days per year above 90°F.
How cold are winters in San Diego County?
The average winter temperature (December-February) in San Diego County is 53.4°F. January, typically the coldest month, averages 53.5°F.

Track your own weather in San Diego County

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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