• Knightia eocaena mass mortality

    Fossil Butte

    National Monument Wyoming

Weather

thunderstorm
NPS photo
 

Expect a variety of weather conditions no matter what time of year you visit. Local weather conditions and extended forecasts are available on the National Weather Service's (NOAA) web page.



Warm days (70–90 degrees F) and moderate evenings (30–50 degrees F) are the norm for summer months. Most evenings require a light jacket. Light frosts are common on summer nights. Yes, it can snow in July.



Spring, fall and winter can be very cold; expect snow and winter conditions.

Did You Know?

Diplomystus dentatus, NPS photo of Fossil Country Museum specimen

Railroad workers played a major role in the discovery of fossils from the Green River Formation. In the late 1860's, Union Pacific workers uncovered the first major fossil fish beds (Lake Gosiute) near the town of Green River, Wyoming.