Historical weather data, all-time temperature records, and monthly climate averages for Pasadena, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4 in Pasadena lands right in the sweet spot of spring — expect a comfortable 72° high and 48° low on average. There's a 1-in-5 chance of rain, though the date has seen real swings: a scorching 99° in 1989 and a teeth-chattering 35° low back in 1918.
Pasadena is no stranger to extremes — this inland SoCal city hit a brutal 115° on September 6, 2020, and has dipped as low as 21° in January 1913. Rainfall can be dramatic too, with a single day dropping 7.7 inches on March 2, 1938, and even the occasional snowfall, including a 3-inch surprise in January 1949.
Pasadena peaks in late summer, with average highs hitting 90° during the last days of July into early August, while the coolest stretch is New Year's week at a mild 66°. If you're trying to dodge rain, aim for summer — the wettest window runs mid-to-late February, averaging over an inch of precip in a single week.