When Is Summer in Las Vegas? June Through September

Las Vegas has a hot desert climate (Köppen BWh). The summer season runs June through September, characterized by:

• Extreme heat: Average July high 106 °F (41 °C); lows around 77 °F (25 °C).
• Low humidity: Often below 10%, making shade feel cooler but increasing dehydration risk.
• Monsoon influence: Late summer (July–Sept) brings occasional thunderstorms and flash-flood risk.

Shoulder months May and October are warm (90s °F / 30s °C) and popular with visitors. Winter (Dec–Feb) is mild, with highs near 60 °F (15 °C) and rare freezing nights.