April weather forecast
Yellowstone National Park, WY

April observes a significant warming trend with the park's fauna coming fully alive after the long and arduous winter. A substantially reduced snowfall of 21.4" (544mm) combined with longer daylight and sunshine hours makes for pleasant day trips. Though rainfall occurrence increases, it's the continued transition from snow that dominates the weather pattern. Adventurous visitors may capture the park's dramatic spring awakening. Expect encounters with roaming elk, bison, and other wildlife species.

Temperature

The onset of April in Yellowstone National Park marks a slight increase in the average high-temperature, moving from a wintry 36.1°F (2.3°C) in March to a chilly 43.3°F (6.3°C). April nights see a notable contrast from daytime highs, with the nighttime temperature averaging at a freezing cold 18°F (-7.8°C).

Rainfall

In Yellowstone National Park, in April, during 11.6 rainfall days, 1.77" (45mm) of precipitation is typically accumulated. Throughout the year, in Yellowstone National Park, Wyoming, there are 151 rainfall days, and 20.91" (531mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through June, September through December. In Yellowstone National Park, in April, snow falls for 9.5 days, with typically accumulated 21.42" (544mm) of snow. Throughout the year, in Yellowstone National Park, there are 91.4 snowfall days, and 193.7" (4920mm) of snow is accumulated.

Daylight

In April, the average length of the day in Yellowstone National Park is 13h and 30min.
On the first day of the month, sunrise is at 7:01 am and sunset at 7:50 pm. On the last day of April, sunrise is at 6:12 am and sunset at 8:25 pm MDT.

Sunshine

The average sunshine in April in Yellowstone National Park is 8h.

UV index

In April, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: In April, a regular UV index of 6 translates into these guidelines:
Avert overexposure. Light-skinned people might experience burning in less than 20 minutes. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.