Historical weather data, all-time temperature records, and monthly climate averages for Brea, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Brea typically feels like a preview of summer, with an average high of 73° and almost no chance of rain at just 11%. The date has seen a wide swing historically — from a balmy 89° in 2016 down to a chilly 41° low back in 1999, so pack a layer if you're heading out in the morning.
Brea runs hot — and occasionally surprises on the cold end. The all-time high hit a brutal 112° on September 6, 2024, while the coldest recorded day bottomed out at 30° in January 2002. The wettest single day on record dropped 6.73 inches on January 18, 2010, a reminder that when Southern California storms show up, they can really show up.
Brea is warm year-round, with average highs that never dip below 69° even in the dead of winter. Peak heat arrives in late summer — the first week of September averages a high of 90° — while late December is the coolest stretch at 69°. If you want to avoid the rain, skip February, when the wettest week of the year averages nearly an inch of precipitation.