Historical weather data, all-time temperature records, and monthly climate averages for San Bernardino, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in San Bernardino tends to be a pleasant spring day, with highs averaging 74° and lows around 46°. There's only a 17% chance of rain, though the date has seen some wild swings — a scorching 92° in 1960 and a near-freezing 33° back in 1955.
San Bernardino is no stranger to extremes, sitting in the inland valley where heat bakes and cold snaps bite. The all-time high of 113° in September 1955 and an all-time low of 20° in January 1949 tell the full story — this city runs the gamut. Winter storms can also pack a punch, with a single-day record of 4.03 inches of rain and 6.5 inches of snow, both set in that same brutal winter of 1949.
San Bernardino is a summer-dominant climate, with highs peaking at 95° in mid-July and staying there through August before a gradual cool-down into fall. Winters are mild by most standards — January highs hover around 63° — but that's when the rain arrives, with late January being the wettest stretch of the year. If you're planning a visit, spring and fall offer the most comfortable conditions before the inland heat takes hold.