Ontario, California Weather:
Friday, September 18, 2026
Sunny Weather
Day 88°
Night 61°
Precipitation 2 %
Wind 5 mph
UV Index (0 - 11+) 7
Weather Forecast History
Last Year's Weather on This Day (September 18, 2025)
Stormy Weather

Day

84°

Night

66°

Wind

6 mph

Precipitation

55 %