When is the last frost in Granite, CO?

For ZIP code 81228, the average last spring frost (32°F) is June 16, based on NOAA 1991-2020 climate normals for the Twin Lakes Rsvr, CO weather station. There is a 1-in-10 chance of a frost after June 29.

When is the first frost in Granite, CO?

The average first fall frost (32°F) is September 10. There is a 1-in-10 chance of frost by August 24, so tender plants are at risk from that point on.

How long is the growing season in 81228?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 85 days long.

Are these frost dates a forecast?

No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.

Frost dates for 81228Granite, CO

The average last spring frost in Granite is June 16 and the average first fall frost is September 10, giving a typical growing season of about 85 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jun 16
Average first fall frost: Sep 10
Growing season: 85 days

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
Temperature	Last spring: 90% / 50% / 10% chance	First fall: 10% / 50% / 90% chance	Growing season (50%)	Years with at least one
Light frost (36°F)	—	—	50 days	100%
Frost / freeze (32°F)	Jun 3 · Jun 16 · Jun 29	Aug 24 · Sep 10 · Sep 23	85 days	100%
Hard freeze (28°F)	May 17 · Jun 2 · Jun 16	Sep 9 · Sep 23 · Oct 4	112 days	100%

Where these dates come from

ZIP code 81228 is matched to the NOAA station Twin Lakes Rsvr, CO, 10.8 km away, at 9,236 ft elevation (6 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Twin Lakes Rsvr, CO (used)	9,236 ft	Jun 16	Sep 10
Leadville Lake Co Ap, CO	9,933 ft	—	—
Buena Vista 2S, CO	7,954 ft	May 27	Sep 23
Sugarloaf Rsvr, CO	9,738 ft	—	—

Frost dates near Granite

Twin Lakes, CO 81251 · last —, first —
Climax, CO 80429 · last —, first —
Buena Vista, CO 81211 · last May 27, first Sep 23
Leadville, CO 80461 · last —, first —
Fairplay, CO 80440 · last Jun 16, first Sep 9
Alma, CO 80420 · last Jun 16, first Sep 9
Hartsel, CO 80449 · last —, first —
Nathrop, CO 81236 · last May 27, first Sep 23

Frequently asked questions

When is the last frost in Granite, CO?: For ZIP code 81228, the average last spring frost (32°F) is June 16, based on NOAA 1991-2020 climate normals for the Twin Lakes Rsvr, CO weather station. There is a 1-in-10 chance of a frost after June 29.
When is the first frost in Granite, CO?: The average first fall frost (32°F) is September 10. There is a 1-in-10 chance of frost by August 24, so tender plants are at risk from that point on.
How long is the growing season in 81228?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 85 days long.
Are these frost dates a forecast?: No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.