San Bernardino Weather & Climate: Best Time to Visit

The climate in San Bernardino experiences moderate temperature changes, with mild shifts between seasons. Average maximum daytime temperatures range from a very warm 34°C (93°F) in January, the warmest time of the year, to a comfortable 24°C (75°F) during cooler months like July.

At night, you can expect temperatures ranging from 23°C (73°F) in January to around 13°C (55°F) during July.

Check out our detailed temperature page for more information.

Temperature ranges by month

San Bernardino experiences significant rainfall throughout the year, averaging 1638 mm (64 in) of precipitation annually. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, October it receives heavy rainfall, averaging 198 mm (7.8 in) of precipitation, recorded across 7 rainy days. In contrast, the driest month August brings less rainfall, with 71 mm (2.8 in) over 5 rainy days. For more details, please visit our San Bernardino Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

Seasonal changes in sunshine hours are quite dramatic in San Bernardino. While December receives considerable daily sunshine with up to 9.9 hours, June marks the darkest time of the year, where sunshine is scarce with only 5.5 hours of sunlight per day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

The relative humidity is high throughout the year in San Bernardino.

The city experiences its highest humidity in May, reaching 76%. In September, the humidity drops to its lowest level at 65%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year