Extreme high temperatures in the summer stress forests and wildlife. These days increase water loss from transpiration and can damage trees. Additionally, extreme high temperature days increase the risk and severity of wildfires.
To measure extreme high temperature days the FHI looks at temperature measurements from a combination of on-the-ground sensors and satellite data. We count the number of days each summer that exceed 90th percentile in a normal summer about 10 days will meet this criteria.
Near average: The number of extreme high-temperature days was near average for this watershed last year. Forests are well adapted to these conditions.
Colorado's forests have evolved with occasional extreme high temperature days. Similar to humans, forests can withstand hot conditions for limited amount of time but persistent extreme heat may cause stress for many plants and animals. Forests at the lower end of their elevational range and on south facing slopes are often most exposed to warmer temperatures, but as the climate warms, extremely warm conditions may also begin to impact high elevation forests and north facing slopes.
Climate change is increasing temperatures across the country. While the average temperature is almost sure to increase, predictions about temperature extremes are more uncertain. In addition to impacting forests, extreme temperatures can also impact animals, including humans. In many years, more people in the US die from extreme temperatures than any other natural disaster.