Last Day of Spring Frost in Boulder
Data from 1949-1996
Frost is defined here as the minimum temperature being less than or equal to 32 F. Frost may occur even when the official temperature is above 32F as the ground can be colder than where the thermometer is located (typically 3 meters above the surface).earliest day of last frost: Apr 10 (1956) latest day: Jun 3 (1951) average: May 3 median May 1 standard deviation 11.1 days
