Late summer is the hottest time of year for the Colorado Plateau’s high desert. It’s also monsoon season when afternoon thunderstorms are probable. Monsoon season in the Southwest “officially” begins in mid-July and ends in mid-September. Thunderstorms – with lightning and thunder – are most common in the afternoon but they can happen at any time.
These monsoon thunderstorms also bring heavy rain causing flash flooding in the canyons. Monsoon storms can be powerful and sudden. Water can rise quickly downstream from heavy rain, even when the parent thunderstorm is miles away! Monsoon season in Utah is well known to hikers because many of our favorite spots for camping and recreation frequently see flash flooding.