When is the last frost in Placerville, ID?

For ZIP code 83666, the average last spring frost (32°F) is June 17, based on NOAA 1991-2020 climate normals for the Idaho City, ID weather station. There is a 1-in-10 chance of a frost after July 4.

When is the first frost in Placerville, ID?

The average first fall frost (32°F) is September 5. There is a 1-in-10 chance of frost by August 23, so tender plants are at risk from that point on.

How long is the growing season in 83666?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 80 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 83666Placerville, ID

The average last spring frost in Placerville is June 17 and the average first fall frost is September 5, giving a typical growing season of about 80 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jun 17
Average first fall frost: Sep 5
Growing season: 80 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)	—	—	52 days	100%
Frost / freeze (32°F)	May 30 · Jun 17 · Jul 4	Aug 23 · Sep 5 · Sep 21	80 days	100%
Hard freeze (28°F)	May 7 · May 22 · Jun 14	Sep 3 · Sep 19 · Oct 5	117 days	100%

Where these dates come from

ZIP code 83666 is matched to the NOAA station Idaho City, ID, 18.1 km away, at 3,965 ft elevation (1,081 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Idaho City, ID (used)	3,965 ft	Jun 17	Sep 5
Garden Valley, ID	3,100 ft	Jun 1	Sep 10
Boise 7 N, ID	3,885 ft	May 17	Oct 12
Lowman, ID	3,920 ft	Jun 6	Sep 4

Frost dates near Placerville

Horseshoe Bend, ID 83629 · last Apr 30, first Oct 17
Banks, ID 83602 · last Jun 1, first Sep 10
Garden Valley, ID 83622 · last Jun 17, first Sep 5
Idaho City, ID 83631 · last Jun 17, first Sep 5
Sweet, ID 83670 · last Apr 30, first Oct 17
Garden City, ID 83714 · last Apr 24, first Oct 21
Ola, ID 83657 · last May 31, first Sep 16
Mountain Home Afb, ID 83648 · last Apr 30, first Oct 17

Frequently asked questions

When is the last frost in Placerville, ID?: For ZIP code 83666, the average last spring frost (32°F) is June 17, based on NOAA 1991-2020 climate normals for the Idaho City, ID weather station. There is a 1-in-10 chance of a frost after July 4.
When is the first frost in Placerville, ID?: The average first fall frost (32°F) is September 5. There is a 1-in-10 chance of frost by August 23, so tender plants are at risk from that point on.
How long is the growing season in 83666?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 80 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.