Information Sheet on Hail in Colorado
Nolan J. Doesken, State Climatologist
Colorado Climate Center
Department of Atmospheric Science
Colorado State University
Fort Collins, Colorado 80523
Colorado is one of the most hail-prone states in the U.S.
Hail occurs more frequently in the lee of the Rockies than anywhere else in North America.
Hail is more variable (from place to place and year to year) than almost any other climatic event.
Destructive hail occurs most frequently on the western Great Plains.
Strong winds accompanying hail greatly increase the damage potential.
The highest frequency of damaging hail appears to occur near the border of Wyoming, Nebraska, and Colorado.
The Colorado hail season is April 15 to September 15.
Colorado hail storms occur most frequently in June and are most likely to be destructive in mid June. However, in parts of southeastern Colorado, including Pueblo, August is the worst hail month.
Hailstones of 1 to 2 inch diameters (which may fall at a rate of 80 miles per hour) occur many times in eastern Colorado each summer but fortunately occur over small areas.
Stones as large as 4.5 inches in diameter have been observed in northeastern Colorado and can do incredible damage. Stones of that size have been know to penetrate some roofs.
One death and numerous injuries have occurred in Colorado as a result of hail.
Hail also occurs very frequently in the high Colorado mountains during the summer. These stones, however, tend to be small and soft and rarely do damage.