Historical weather data, all-time temperature records, and monthly climate averages for Norco, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
Norco sits in Southern California's Inland Empire, where the Santa Ana winds and inland heat create some of the most dramatic temperature swings in the region. Historically, today's date has seen the full range this area is known for — mild and sunny one year, scorching the next.
Norco has baked as hot as 113° (July 22, 2006) and dipped as low as 34° (January 13, 2007) — a 79-degree spread that captures just how extreme inland SoCal can get. Most days land nowhere near those edges, but the ceiling and floor are real.
Summers run hot, with late August through early September averaging highs around 90° — the warmest stretch of the year. Winters are mild by most standards, with February highs hovering around 63-64°. Rain is rare but concentrated in early January when it does show up.