Monthly weather forecast and climate
Zion National Park, UT

Zion National Park experiences a cold desert type of climate (Köppen climate classification BWk) manifested in hot summers and cold winters with a meager amount of rainfall throughout the year.
Park lies in southwestern Utah near Springdale, between the Dixie and the Canyon Country regions, at the intersection of the Colorado Plateau, the Great Basin, and the Mojave Desert. Zion National Park has four life zones: woodland, coniferous forest, desert, the riparian, and the varied topography of canyons, mesas, mountains, soils, and rivers - significant temperature variations exist by zones, altitude and time, sometimes even to the tune of 30 degrees.

Spring is a mix of wet and warm weather with occasional stormy and sunny days.
Summers are hot with an average high temperature of 101°F (38.3°C) in the peak of July, as afternoon thunderstorms are common which frequently lead to flash floods; day highs sometimes touch a blazing 110°F (43.3°C), while nights are comparatively cold.
Autumn is usually mild, displaying spectacular tree colors by October.
Winters are cold and damp as the lows regularly drop below freezing in the 20°F (-6.7°C) to 30°F (-1.1°C), while highs are at a mild 55°F (12.8°C) to 60°F (15.6°C). Snowfall accumulates up to 4.2" (106.7mm) during the winter, while the annual precipitation is scanty to the tune of 16.1" (408.9mm) spread throughout the year.

May to November is usually the high tourist season. However, the best time to visit Zion National Park is in the border months when the crowds are scarce - May in the aromatic spring and October and November in the beautiful autumn with mild temperatures in the 60°F (15.6°C) to 70°F (21.1°C) range.
Summer months are crowded as the park ranks high in visitor rankings, and the temperatures easily cross 100°F (37.8°C) during the peak. Additionally, area accommodations are at a premium from June to September, as the park runs a free shuttle service for various trails and attractions.

December to April is a time to avoid Zion National Park as the winter months are cold and damp. Snowfall is regular in winter in moderate quantities, while frost is regular - the temperatures drop to 20°F (-6.7°C). Some of the attractions are frigid to enjoy as the closure of the free shuttle service in winter necessitates the use of own vehicles in the frosty weather.
A few tourists with a taste for adventure find the accommodations cheap during the winter and enjoy nature with no disturbances from the summer crowds.

Flash floods mainly occur during the summer when Zion is prone to thunderstorms with heavy rain. They happen very quickly and are deadly, as they carry a large amount of debris in the form of boulders and trees. Slot canyons are particularly dangerous for flash floods as water can knock off a person with its tremendous force.
Zion National Park has established a flash flood warning system for the safety of the tourists.

January is a cold winter month as the beginning of the year experiences temperatures in the cold 30°F (-1.1°C) to mild 54°F (12.2°C) range. Weather in January »

February is the warmer of the winter months, with an average high temperature of 58°F (14.4°C). Average low temperature is above freezing at 33°F (0.6°C). Weather in February »

March is the wettest month of the year with the rain gauge at 2.1" (53.3mm) and begins the unpredictable spring season. Weather in March »

April improves warmth in Zion as the mercury rises to 74°F (23.3°C) during the day. The sun increases its daily presence as the skies become clear. Weather in April »

May is one of the best periods to be in Zion with the temperatures in a pleasant range of 52°F (11.1°C) to 85°F (29.4°C). Rain is negligible, but layered clothing is advisable. Weather in May »

June is the beginning of the summer and the peak tourist season in Zion. The mercury column lies between a warm 62°F (16.7°C) and a hot 96°F (35.6°C) on an average. Weather in June »

July is the hottest month of the year, with the average high temperature at an astounding 101°F (38.3°C). The trails are blazing in the scorching sun as some days hit an amazing 115°F (46.1°C). Weather in July »

August is a warm summer month with average high temperatures of 98°F (36.7°C) and the average low temperatures of 67°F (19.4°C). Weather in August »

September is the start of the gorgeous autumn season in Zion with temperatures in a comfortable 62°F (16.7°C) to 91°F (32.8°C). Weather in September »

The average temperatures vary from a mildly cold 48°F (8.9°C) to 78°F (25.6°C). Mild rain to the tune of 1.3" (33mm) accumulates in October, so it is a good idea to wear full sleeves or light jackets. Weather in October »

November is a wonderful autumn month with pleasant weather in Zion. The days are short, but there is still ample sunlight to explore the park. Weather in November »

December is the coldest month of the year in Zion National Park with the average low temperature at a frigid 29°F (-1.7°C), while many days register temperatures of approximately 20°F (-6.7°C). Weather in December »