Fort Collins, CO Frost Dates

The last spring frost in Fort Collins usually comes around May 2 and the first fall frost around October 7.

Spring (last)Fall (first)
Frost, 32°FMay 2October 7
Hard freeze, 28°FApril 20October 17

Growing season: about 157 days.

Frequently asked questions

When is the last frost in Fort Collins, CO?

The median date of the last spring frost (32°F) is May 2. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past May 2 lowers the risk for tender plants.

When is the first frost in Fort Collins?

The median date of the first fall frost (32°F) is October 7, and a hard freeze (28°F) usually follows around October 17.

How long is the growing season in Fort Collins?

About 157 days between the median last spring frost and first fall frost.

NOAA NCEI U.S. Climate Normals 1991-2020, station USC00053005. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.

Fort Collins weather by month · Frost dates for every city