The hail season in Colorado begins in March and ends in October. Overall, the month of June has the highest frequency of days with hail.
In Colorado, 90% of all severe hailstorms from 1986-1993 occurred between 1:00 pm and 9:00 pm. However, hailstorms tend to occur earlier in the day in the mountains, and later in the day in the eastern parts of the state.
The number of reported severe hailstorms appears to be increasing due to an increase in the population and an increase in the number of cellular phones, not because the number of storms is actually increasing.
The National Weather Service defines severe hailstorms as storms which result in hail that have a 0.75 inch or greater in diameter.
While the majority of hailstones in Colorado are less than 0.5 inch in diameter, the most common size range for damaging hail in Colorado is 1.0 - 1.5 inches in diameter.
Severe hail is not a problem statewide, but is limited to eastern Colorado beginning in the eastern foothills, and extending across all the Eastern Plains.
An exact distribution of hailstorms is difficult to determine because hailstorms generally occur over a small region and may go unnoticed in rural areas. On the other hand, hailstorms are frequently reported anywhere people are found and where property damage is likely to have occurred: in towns, cities, and along highways.
