September weather forecast
Grand Canyon National Park, AZ

September brings the transition from hot summers to milder autumns. Throughout the month, visitors witness temperatures easing off from the hot summer peaks to a more pleasant 93°F (33.9°C). Rainfall levels decline while daylight hours shorten, suggesting the end of summer. However, the park receives significant sunlight, making the landscape glow in autumnal hues. Visiting the park during this month ensures more comfortable weather conditions.

Temperature

The shift from August to September in Grand Canyon National Park includes a small decrease in the average high-temperature, from a sweltering 100°F (37.8°C) to a hot 93°F (33.9°C). A noticeable temperature swing characterizes Grand Canyon National Park's September nights, dipping to an average of 66°F (18.9°C).

Rainfall

In September, in Grand Canyon National Park, the rain falls for 3 days. Throughout September, 1.02" (26mm) of precipitation is accumulated. In Grand Canyon National Park, during the entire year, the rain falls for 33 days and collects up to 9.69" (246mm) of precipitation.

Snowfall

In Grand Canyon National Park, snow does not fall in February through November.

Daylight

The average length of the day in September in Grand Canyon National Park is 12h and 23min.
On the first day of the month, sunrise is at 6:00 am and sunset at 6:55 pm. On the last day of September, in Grand Canyon National Park, sunrise is at 6:23 am and sunset at 6:12 pm MST.

Sunshine

In Grand Canyon National Park, the average sunshine in September is 10h.

UV index

In September, the average daily maximum UV index in Grand Canyon National Park is 8. A UV Index of 8 to 10 symbolizes a very high health hazard from unsafe exposure to UV radiation for the average person.
Note: In September, the maximum UV index of 8 transforms into these recommendations:
Always stay safe. Unprotected skin and eyes can get damaged rapidly. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.