Arizona Monsoon Season Guide

The North American Monsoon is Arizona’s most spectacular annual event, and it isn’t held anywhere — it happens to you. Officially running June 15 through September 30, it peaks in July and August, when afternoon heat and Gulf moisture stack up into towering thunderheads that unload dry lightning, flash floods, and haboobs — dust walls thousands of feet tall that roll over Phoenix and turn day to brown twilight in minutes. It delivers a huge share of the desert’s annual rain in a handful of violent afternoons. There is nothing else like standing on a ridge at dusk watching lightning fork across fifty miles of open desert.