A severe heatwave is affecting millions of Americans across the western United States this week, bringing unseasonably warm and dangerous temperatures from the Pacific coast to the Rocky Mountains. Temperatures have reached up to 30 degrees Fahrenheit above average for this time of year.

The most extreme reading came from Martinez Lake, Arizona, a small desert community located approximately 145 miles west of Phoenix. The area recorded a temperature of 110°F (43.3°C) on Thursday, according to the National Weather Service, setting a new record for the highest March temperature ever recorded in the United States.

Scientists have analyzed the current weather patterns and determined that this record-breaking heatwave would have been "virtually impossible" without climate change. The research team's analysis highlights the role of long-term climate trends in enabling such extreme temperature events.

The timing of the heatwave coincides with what is expected to be a record-breaking spring travel season, as Airlines for America projects 171 million passengers will fly during the spring period - a 4% increase from 2025. The extreme weather conditions are contributing to travel disruptions alongside other factors including potential airport security delays and high fuel prices.

The current heatwave represents part of a broader pattern of extreme weather events affecting travel and daily life across the southwestern United States during what is typically a cooler time of year.