Weather Service forecast for the Petrified Forest area.
Generally, except for Thanksgiving and Christmas Day, Petrified Forest National Park is open every day. During the winter there may be a delay in opening the park until the roads are safe. Check the Alerts at the top of the page or our Facebook and Twitter sites for delay and closure announcements.
Monsoon Season: June 15–September 30
Officially, it is monsoon season from June 15 through September 30 in Arizona and much of the Southwest. Severe thunderstorms are possible. While the season officially begins on June 15, often the park doesn't see its first seasonal storm until early July. After that, it is common for thunderclouds to develop each day when conditions are optimal.
Some storms are severe and drop enough rain at once to cause flooding. Flash floods come quickly and can be dangerous. Do not try to cross a flooded wash or road! Remember: Turn around, don't drown!
Lightning can also pose a hazard this time of year. It can travel farther than most people realize. You are often the tallest thing in this landscape. Time your activity to be indoors in the afternoon. If you are outside during a storm, head back to your car. The shade structures have metal roofs.
It can be a dramatically beautiful time of year. With a little planning, you can enjoy the park when the moisture has truly brought out the color and patterns in formations and petrified wood.
Last updated: May 18, 2023