Historical weather data, all-time temperature records, and monthly climate averages for Rosemead, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Rosemead sits in that sweet-spot stretch of spring, with average highs of 72° and lows of 48°. The date has seen wild swings over 120 years of records — from a scorching 99° in 1989 to a teeth-chattering 35° back in 1918. There's about a 1-in-5 chance of rain today, but you can leave the snow shovel in storage.
Rosemead plays it warm most of the year, but its extremes are no joke — the mercury has hit 115° as recently as September 2020 and plunged to 21° in January 1913. When the rain does come, it can come hard: a single day in March 1938 dropped 7.7 inches, and even 3 inches of snow fell on January 11, 1949.
Rosemead is warm year-round, with highs never dipping below the mid-60s even in the depths of January. Peak summer runs late July through early August, when average highs reach 90°, while the wettest stretch falls in late February, averaging just over an inch for the week. If you want sunshine and mild temps, spring and fall deliver highs in the 70s and 80s with minimal rain.