Rancho Cucamonga, California Weather:
Thursday, May 21, 2026
Cloudy Weather
Day 82°
Night 59°
Precipitation 0 %
Wind 7 mph
UV Index (0 - 11+) 11
Weather Forecast History
Last Year's Weather on This Day (May 21, 2025)
Sunny Weather

Day

93°

Night

61°

Wind

7 mph

UV Index

11

Precipitation

1 %