When to Go
The park's high season is July and August. September and early October tend to draw smaller crowds. From October well into June, nearly the entire park closes due to heavy snowfall. The road is kept open just from the South Entrance to the rim in winter, except during severe weather. Early summer snowmelt often creates watery breeding areas for large groups of mosquitoes. Bring lots of insect repellent in June and July, and expect mosquito swarms in the early morning and at sunset. They can also be a problem later in the summer in campgrounds and on the Cleetwood Cove Trail, so pack repellent if you plan on camping or hiking. You might even consider a hat with mosquito netting.