While Zion weather always has an element of unpredictability, springtime has an even greater variety than normal. It could be cold and raining in the morning, then be perfect in the afternoon, when the sun burns off the clouds.
Precipitation is highest in March, normally around 1.7 inches. The water helps push spring flowers to a pinnacle in May. Temperatures normally range from the mid-30s to the mid-70s, though spring can see more extreme variations.
While some wait for the sunny summer to avoid the unpredictable weather, others take advantage of the smaller crowds to enjoy the budding Zion spring season when the desert is breaking away from the long winter nights.
The sun is strong and high in the summertime, shining directly onto the exposed sandstone, which absorbs and radiates the heat. The dry air and stifling temperatures make overheating and dehydration serious issues.
With just a little preparation, however, these hazards are easily avoided: always carry water, wear a hat and sunblock, and take plenty of breaks in the shade.
Thunderstorms are common events during the summer, meaning that visitors need to be prepared to either take cover or weather the storm outside.
August has the highest amount of rain at 1.6 inches, while June and July are relatively dry. Temperatures are in the high 90s, dropping to the mid-60s during the night.
The mild and cool Zion National Park weather prevails in the fall, making a perfect time to visit. In the high country of the park, leaves start to show their colors in September, while the trees in Zion Canyon don't finish their autumn displays until November.
If you're thinking about visiting Snow Canyon and St. George, weather should be excellent during this time of year. A light sweater should be all that is needed for a day out, and a heavier layer for the night chills.
Early September will be hot, but the temperatures quickly drop to the 60s in October and November. Nighttime temperatures start to drop as well, reaching the upper 30s in November. There are generally only four or five days a month with precipitation.
Well known by golfers who visit St. George, Utah, weather during winter is pleasant. Reaching highs around 60°F during the day, they can drop back down to the mid-20s at night.
Temperatures in Zion will be a little cooler, generally in the mid-50s, but days above 70°F are not uncommon. There is some rain, and even snow in the high country, but generally only six or seven days a month.
One of the best parts about the winter is the Zion Canyon Scenic Byway. Normally closed to private traffic, winter visitors get the chance to drive up the canyon themselves for a truly unique experience.
Visitors should be prepared for winter driving conditions, with snow and ice on the roads. All roads are plowed and maintained except Kolob Terrace Road, of which only the first 14 miles are plowed.
Throughout the Year
It can rain anytime of the year in Zion, so be sure to check the flash flood potential ratings at the park visitors center if entering any of the narrow canyons.
Temperatures often vary by 30 degrees or more, whether in summer or winter, so always come prepared. Carrying an additional layer of clothing and water is an easy way to prepare for the unexpected.
Elevation and sun exposure have a significant effect on temperature. As trails ascend canyons walls, with thigh-burning steps gaining perspective and altitude, temperatures will drop considerably. Exposed rock faces radiate the sun's heat, while shaded canyons can feel chilly, even on a 100°F day.