Climate Change

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Snowfall in Yellowstone melts into rivers that span the continent from the Gulf of Mexico to the Pacific Ocean. Scientists are documenting significant changes in the amount of snow that falls here as well as the intensity and timing of spring runoff. These trends could affect everything you see when you come to the park, as well as everyone and everything living downstream.


Yellowstone's climate is changing. Climate is one of the primary drivers of the processes that make an ecosystem look and function the way it does. Weather reflects the short-term conditions of the atmosphere. Climate consists of the long-term averages of daily weather, usually in 30-year periods. Change in climate can greatly alter ecosystems.

Scientists have monitored Yellowstone's climate for decades. Studying climate is complicated and the impacts of climate change are difficult to predict. Current research indicates Yellowstone's temperature will continue to rise over the next century, but the behavior of precipitation is more difficult to predict. Scientists have already documented these changes in Yellowstone:

  • Average temperatures in the park are higher now than they were 50 years ago, especially during springtime. Nighttime temperatures seem to be increasing more rapidly than daytime temperatures.
  • In the last 50 years, the growing season (the time between the last freeze of spring and the first freeze of fall) has increased by roughly 30 days in some areas of the park.
  • At the northeast entrance, there are now 60 more days per year above freezing than there were in the mid-1980s.
  • There are approximately 30 fewer days per year with snow on the ground than there were in the 1960s.

You can compare historic averages to projected averages for Greater Yellowstone's temperature, precipitation, snow water equivalent, and more with the Greater Yellowstone Area Climate Explorer. Data from weather stations and stream gauges in the greater Yellowstone area are available at The Climate Analyzer.

A continued rise in temperature will fundamentally alter Yellowstone's ecosystem:

  • Likely affecting the composition of plants and animals throughout the park.
  • Altering the amount and timing of spring snowmelt, which affects water levels, vegetation growth, and the movement of wildlife from migrating bison to spawning trout to the arrival of pollinators. As headwaters to significant water basins, any change in the rivers flowing out of Yellowstone affects downstream users like ranchers, farmers, towns, and cities.
  • Fire frequency and season length could increase.

Scientists continue to monitor climate in Yellowstone and are developing models to help predict how park resources might respond to changing conditions. Park managers are reducing the park's carbon footprint by helping employees and visitors replace consumptive habits with more sustainable practices and by sharing the best practices and resources with local communities and partners.

Yellowstone will continue to preserve the park's biodiversity, natural processes, and cultural resources, while also protecting the trails and infrastructure that allow visitors to experience those wonders. As climate change unfolds, the park will share stories of how nature and people adapt to our changing environment.

A view of Mount Washburn with purple flowers in the foreground and a snow patch off in the distance

Changes in Yellowstone Climate

Scientists with the National Park Service and other organizations closely monitor variables that may reflect a changing climate.

A dead tree reflects clearly on the runoff held by the Upper Mammoth Terraces

Climate Change Explorer

The Climate Change Explorer is a tool that compares past averages to future predictions for variables in the Greater Yellowstone Area.

A great blue heron preparing to take flight in the early morning along the Yellowstone River

Examining the Evidence

Climate change is predicted to cause birds to shift their range, migratory patterns and timing, and interfere with reproduction.



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Last updated: June 25, 2019

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