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Alaska · NOAA station USW00025367

Frost dates for Klawock Airport, AK

At Klawock Airport, the median last spring frost (32°F) is Apr 29 and the median first fall frost is Oct 16, for a typical growing season of 169 days. For a 90% chance that the last frost has passed, wait until May 14. Nearby ZIP codes are in USDA hardiness zone 7b.

  • Apr 29Last spring frost (median)50% chance of 32°F after this date
  • May 14Safer planting date10% chance of 32°F after this date
  • Oct 16First fall frost (median)50% chance of 32°F by this date
  • 169 daysGrowing season (median)between 32°F freezes

Planting date calculator

Pick how much frost risk you accept and how many weeks before or after the last frost your seed packet says to plant.

From your seed packet, e.g. “start 6 weeks before last frost”.

–Last spring frost
–First fall frost
–Your planting date
–Hardiness zone

Last spring frost dates

The chance that the temperature drops to the threshold after each date.

Klawock Airport: last spring freeze by temperature
Temperature90% chance later50% chance later10% chance later
36°FMay 4May 19Jun 3
32°FApr 13Apr 29May 14
28°FMar 20Apr 9Apr 28
24°FFeb 19Mar 16Apr 7

First fall frost dates

The chance that the temperature has dropped to the threshold by each date.

Klawock Airport: first fall freeze by temperature
Temperature10% chance by50% chance by90% chance by
36°FSep 19Oct 1Oct 17
32°FOct 1Oct 16Nov 5
28°FOct 14Nov 5Nov 28
24°FNov 2Nov 26Dec 23

Growing season length

Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.

Klawock Airport: growing season by temperature
Temperature9 in 10 years at least5 in 10 years at least1 in 10 years at least
36°F116 days136 days156 days
32°F147 days169 days194 days
28°F181 days209 days239 days
24°F222 days252 days288 days

Chance of a freeze in any year

Klawock Airport: probability of at least one day at or below each temperature
TemperatureChance per year
36°F100%
32°F100%
28°F100%
24°F100%

ZIP codes whose closest station is this one

ZIP codes near Klawock Airport with 2023 USDA hardiness zones
ZIPHardiness zoneAvg. extreme lowDistance
999257b5 to 10°F9 km

Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.

About this station

  • NOAA station ID USW00025367, at 55.5800, -133.0750, elevation 4 m (12 ft).
  • Data quality: Representative (10+ years), 22 years of freeze data.
  • Average days per year at or below 32°F: 94.
  • Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.

Nearby weather stations

Sources

Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.

All Alaska stations · How frost dates are calculated