When is the last frost in Kasilof, AK?

For ZIP code 99610, the average last spring frost (32°F) is June 11, based on NOAA 1991-2020 climate normals for the Soldotna 5Ssw, AK weather station. There is a 1-in-10 chance of a frost after July 7.

When is the first frost in Kasilof, AK?

The average first fall frost (32°F) is September 1. There is a 1-in-10 chance of frost by August 11, so tender plants are at risk from that point on.

How long is the growing season in 99610?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 75 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 99610Kasilof, AK

The average last spring frost in Kasilof is June 11 and the average first fall frost is September 1, giving a typical growing season of about 75 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jun 11
Average first fall frost: Sep 1
Growing season: 75 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)	—	—	40 days	100%
Frost / freeze (32°F)	May 26 · Jun 11 · Jul 7	Aug 11 · Sep 1 · Sep 18	75 days	100%
Hard freeze (28°F)	May 9 · May 23 · Jun 6	Aug 28 · Sep 16 · Oct 2	113 days	100%

Where these dates come from

ZIP code 99610 is matched to the NOAA station Soldotna 5Ssw, AK, 14.3 km away, at 180 ft elevation (75 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Soldotna 5Ssw, AK (used)	180 ft	Jun 11	Sep 1
Sterling 6Sw, AK	292 ft	May 20	Sep 21
Kenai Muni Ap, AK	91 ft	May 24	Sep 12
Kenai 9N, AK	126 ft	May 18	Sep 22

Frost dates near Kasilof

Clam Gulch, AK 99568 · last Jun 11, first Sep 1
Soldotna, AK 99669 · last Jun 11, first Sep 1
Sterling, AK 99672 · last May 20, first Sep 21
Kenai, AK 99611 · last May 24, first Sep 12
Ninilchik, AK 99639 · last May 10, first Sep 29
Nikiski, AK 99635 · last May 18, first Sep 22
Anchor Point, AK 99556 · last May 27, first Sep 22
Tyonek, AK 99682 · last May 18, first Sep 22

Frequently asked questions

When is the last frost in Kasilof, AK?: For ZIP code 99610, the average last spring frost (32°F) is June 11, based on NOAA 1991-2020 climate normals for the Soldotna 5Ssw, AK weather station. There is a 1-in-10 chance of a frost after July 7.
When is the first frost in Kasilof, AK?: The average first fall frost (32°F) is September 1. There is a 1-in-10 chance of frost by August 11, so tender plants are at risk from that point on.
How long is the growing season in 99610?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 75 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.