Today | Weather | Wednesday, March 18, 2026
Active Weather Warnings

Weather in San Bernardino, California

06:04 AM
Now
Cloudy Night
61° F
Feels Like 61°
Precipitation 39 %
Wind 4 mph
Humidity 49 %
Today
Hot Day
Day 100°
Night 61°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 6

San Bernardino Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (March 18, 2025)
Cloudy Weather

Day

68°

Night

43°

Wind

8 mph

UV Index

6

Precipitation

0 %

Air Quality in San Bernardino

NOW
102 AQI
Unhealthy air quality for sensitive groups Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 36.27 µg/m³
PM10 47.84 µg/m³
O3 0.036 ppm
NO2 4.1 ppb
SO2 0.5 ppb
CO 0.25 ppm
NH3 0.47 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Members of sensitive groups may experience health effects. The general public is not likely to be affected.

Show raw pollutant concentrations (µg/m³)
PM2.536.27 µg/m³
PM1047.84 µg/m³
O371.63 µg/m³
NO27.66 µg/m³
SO21.3 µg/m³
CO286.37 µg/m³
NH30.47 µg/m³
NO0 µg/m³

Weather Alerts and Warnings for San Bernardino

Severe Future Likely

Extreme Heat Watch

Extreme Heat Watch issued March 14 at 5:51AM PDT until March 20 at 8:00PM PDT by NWS San Diego CA
Mar 16, 10:00 AM Mar 20, 8:00 PM
WHAT: Dangerously hot conditions with temperatures 85 to 90 near
the coast, up to 105 inland.

WHERE: Orange County Coastal Areas, Orange County Inland Areas,
San Bernardino and Riverside County Valleys-The Inland Empire, San
Diego County Coastal Areas, San Diego County Valleys, and Santa
Ana Mountains and Foothills.

WHEN: From Monday morning through Friday evening.

IMPACTS: Heat related illnesses increase significantly during
extreme heat events.

ADDITIONAL DETAILS: High temperatures next week will be 20 to
potentially 30 degrees above
normal for this time of year, where record breaking heat is likely.
+ Read More
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes.
Updated: Mar 14, 11:00 AM Source: NWS Alert
Moderate Expected Likely

Heat Advisory

Heat Advisory issued March 18 at 2:49AM PDT until March 20 at 8:00PM PDT by NWS San Diego CA
Mar 18, 2:49 AM Mar 20, 8:00 PM
WHAT: High temperatures in the upper 90s to 104 degrees expected.

WHERE: San Bernardino and Riverside County Valleys-The Inland
Empire.

WHEN: Until 8 PM PDT Friday.

IMPACTS: Hot temperatures may cause heat illnesses.
+ Read More
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke.
Updated: Mar 18, 5:02 AM Source: NWS Alert