Ontario, California Weather:
Active Weather Warnings
Thursday, October 8, 2026
Hot Day
Day 99°
Night 73°
Precipitation 3 %
Wind 5 mph
UV Index (0 - 11+) 5
Weather Forecast History
Last Year's Weather on This Day (October 8, 2025)
Night

Day

77°

Night

54°

Wind

5 mph

Precipitation

1 %

Weather Alerts and Warnings for

Severe Expected Likely

Extreme Heat Warning

Extreme Heat Warning issued October 4 at 11:32AM PDT until October 8 at 8:00PM PDT by NWS San Diego CA
Oct 4, 11:32 AM → Oct 8, 8:00 PM
WHAT: Dangerously hot conditions with high temperatures in the
upper 90s to 105 and warm nights with low temperatures in the low
to mid 70s expected.

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

WHEN: Until 8 PM PDT Thursday.

IMPACTS: Heat related illnesses increase significantly during
extreme heat events.
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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. Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution.
Updated: Oct 4, 2:24 PM Source: NWS Alert