Boulder, Colorado Weather and Climate

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

plot frost