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San Bernardino County Climate

San Bernardino County, California

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec64.8°AVG °F

Avg Annual Temp

64.8°F

Annual Precip

9.7"

Annual Snowfall

10.4"

Extreme Heat Days

111

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.9"
2.2"
1.2"
0.5"
0.2"
0.1"
0.4"
0.3"
0.3"
0.5"
0.6"
1.5"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

10a

Minimum winter temperature range for plant survival

Growing Degree Days

6,007

Excellent for heat-loving crops

Last spring frost (32°F): 02/19
First fall frost (32°F): 11/28

Seasonal Overview

Comfort ZoneSpring56°69°2.0"Summer78°84°0.7"Fall55°77°1.4"Winter47°51°5.6"20°40°60°80°100°

National Comparison

Warmer than 87% of US counties
Wetter than 1% of US counties
More seasonal variation than 16% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: San Bernardino County

Climate Verdict

San Bernardino County has a warm, averaging 64.8°F year-round, arid conditions receiving just 9.7 inches of precipitation annually, significant summer heat with 110.89444444444445 days annually above 90°F, light snow averaging 10.4 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are mild, with January temperatures averaging 48.4°F. summers are hot, with July averaging 83.9°F. The 35°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and July the warmest.

Outdoor & Gardening Guidance

Summer outdoor activities should be planned for early morning or evening to avoid extreme heat.

Regional Context

San Bernardino County is 6.2°F warmer than the California statewide average of 58.7°F, it is also noticeably drier, receiving 16.0 inches less precipitation than the state average, the county experiences 52.22351948151057 more extreme heat days than the state average.

Climate Profile

About San Bernardino County Weather

A massive county with high heat

San Bernardino County averages 64.8°F, placing it well above the national median temperature. It is a dry region, receiving less than 10 inches of annual precipitation.

Warmer than the California average

The county's average of 64.8°F outpaces the state average of 58.7°F by several degrees. However, it is slightly cooler on average than its neighbor, Riverside County.

Drier than coastal counterparts

The county receives just 9.7 inches of rain, which is much lower than San Diego's 14 inches. Despite the heat, it averages 10.4 inches of snow annually due to its high-altitude mountain ranges.

Intense heat and mountain snow

With 111 extreme heat days a year, summers are demanding as July averages 83.9°F. Winter brings a sharp contrast, featuring a 48.4°F January average and significant mountain snowfall.

Manage heat and mountain winter

Residents need high-efficiency cooling for the 111 days of extreme heat. Those in higher elevations must also maintain snow removal equipment and winter vehicle kits.

Frequently Asked Questions

What is the average temperature in San Bernardino County?
The average annual temperature in San Bernardino County, CA is 64.8°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does San Bernardino County get?
San Bernardino County receives an average of 9.7 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 Bernardino County?
Yes, San Bernardino County receives an average of 10.4 inches of snowfall per year according to NOAA climate normals.
How hot does San Bernardino County get in summer?
The average summer temperature (June-August) in San Bernardino County is 81.7°F. The county experiences an average of 111 days per year above 90°F.
How cold are winters in San Bernardino County?
The average winter temperature (December-February) in San Bernardino County is 48.9°F. January, typically the coldest month, averages 48.4°F.

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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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