National Park Service

State of the Park Reports

State of the Park Report for Zion National Park

Resource Brief – Recent Climate Change in Zion National Park

Zion National Park is already experiencing a warmer climate than a century ago.

  • Maximum temperatures in the warmest months are increasing. On average, the number of days above 100° F nearly doubled (26 more days) from 2001–2010 compared to the previous 80 years (Sharrow 2011).
  • Minimum temperatures in the coldest months are also increasing. On average, there are 8 fewer days below freezing than 80 years ago (Sharrow 2011).
  • In the last decade (2001–2010), record high temperatures have been set on 25 to 30 days each year, while record lows have occurred on only 5 to 10 days each year.
  • Spring runoff occurs approximately 10 days earlier than it did 90 years ago (Weissinger and Sharrow, in prep).
  • Many temperature variables are now regularly above their historic range of variability including annual average temperature (see figure below), average temperatures in the warmest and coolest seasons, maximum temperatures in the warmest month, and minimum temperatures in the coldest month (Monahan and Fisichelli 2014).

What do higher temperatures mean for Zion National Park? Some well-documented examples include:

  • Higher temperatures increase water stress on plants that already live in an arid climate. In 1999–2002, the worst recorded drought in over 1,000 years caused a widespread die-off of pinyon pine throughout the Southwest, including several at Zion National Park.
  • Animals intolerant of higher temperatures, like the American pika, are likely to disappear from the highest elevations of the park. This mammal has not been sighted in seven years of recent surveys (2009–2015; photo below).
Mean annual temperature for ZION
The average annual temperature (blue line) at Zion National Park has increased over the past century. The gray line shows temperature averaged over 10-year intervals, and the red asterisk shows the average temperature of the most recent 10-year interval (2003–2012).
The American pika
The American pika

The American pika's habitat is restricted to high elevation talus slopes that provide cool refuges to escape the summer heat. This species, while historically resident in the highest elevations of the park, has not been seen in the last 7 years of survey. There is no cooler, higher habitat for pika to occupy in the park if the current elevation habitat has become too warm.

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Last Updated: June 19, 2017 Contact Webmaster