A massive heat wave is scorching the American West this week, with temperatures breaking records across multiple states. The National Weather Service predicts record-breaking temperatures from California to Missouri, issuing heat warnings for California, Arizona, and Nevada. Daniel Swain, a climate scientist at UC Agriculture and Natural Resources, calls it "the single strongest ridge we've observed outside of summer in any month."

This extreme heat comes as forecasting models predict a strong El Niño event later this year. While 2025 was relatively quiet for climate disasters in the US, these two phenomena could create months of unpredictable weather. Last year saw fewer wildfires than average, with total acres burned falling below the 10-year average, but that pattern may not continue.

The heat wave's duration makes it particularly unusual. Swain notes areas have already seen record highs for a week straight, with another seven to ten days expected. Temperatures in some locations will break April and May records in late March. This prolonged extreme heat, combined with the anticipated El Niño, signals a potentially volatile weather pattern extending into next year.