Thorne Bay, AK frost dates
How Thorne Bay compares
- In 8 years out of 10, the last spring frost in Thorne Bay falls between April 17 and May 16, a 29-day window. The first fall frost falls between October 1 and October 28.
- The median last frost is 20 days earlier than the Alaska median of May 21.
- Its 165-day growing season is longer than 83% of the 165 Alaska places with a regular frost season (state median 124 days).
- The last frost is 26 days later than the zone 7b median of Apr 5. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7b chart.
- The weather station records an average of 118 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 17 |
| 50% (median) | May 1 |
| 10% (safe for tender plants) | May 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 13 |
| 90% (late) | October 28 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Thorne Bay, AK
Thorne Bay, AK frost dates — last frost May 1, first frost Oct 13, zone 7b. whenisthelastfrost.com
When to plant vegetables in Thorne Bay, AK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 6 – Feb 20 | Apr 3 – Apr 17 | — | — |
| Peppers | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Eggplant | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Tomatoes | Mar 6 – Mar 20 | May 8 – May 22 | — | — |
| Lettuce | Mar 6 – Mar 20 | Apr 10 – Apr 24 | Apr 3 – May 8 | Aug 18 – Sep 15 |
| Kale | Mar 6 – Mar 20 | Apr 3 – Apr 17 | Apr 3 – Apr 17 | Aug 4 – Aug 25 |
| Broccoli | Mar 6 – Mar 20 | Apr 17 – May 1 | — | Jul 7 – Jul 28 |
| Cabbage | Mar 6 – Mar 20 | Apr 10 – Apr 24 | — | Jul 7 – Jul 28 |
| Cauliflower | Mar 6 – Mar 20 | Apr 17 – May 1 | — | Jul 7 – Jul 28 |
| Okra | Mar 20 – Apr 3 | May 22 – Jun 5 | May 22 – Jun 5 | — |
| Basil | Mar 20 – Apr 3 | May 8 – May 22 | — | — |
| Peas | — | — | Mar 20 – Apr 10 | Jul 21 – Aug 11 |
| Spinach | — | — | Mar 20 – Apr 10 | Aug 18 – Sep 8 |
| Radishes | — | — | Mar 27 – May 8 | Sep 1 – Sep 22 |
| Cucumbers | Apr 3 – Apr 10 | May 15 – May 22 | May 8 – May 22 | Jul 28 – Aug 11 |
| Zucchini & Summer Squash | Apr 3 – Apr 10 | — | May 8 – May 22 | Aug 4 – Aug 18 |
| Winter Squash & Pumpkins | Apr 3 – Apr 10 | — | May 8 – May 22 | — |
| Melons & Watermelon | Apr 3 – Apr 10 | May 15 – May 29 | — | — |
| Carrots | — | — | Apr 10 – May 8 | Jul 21 – Aug 4 |
| Beets | — | — | Apr 10 – May 8 | Aug 4 – Aug 18 |
| Potatoes | — | — | Apr 10 – May 1 | — |
| Swiss Chard | — | — | Apr 17 – May 15 | Aug 4 – Aug 18 |
| Cilantro | — | — | Apr 17 – May 8 | Aug 18 – Sep 8 |
| Green Beans | — | — | May 8 – May 29 | Jul 28 – Aug 11 |
| Sweet Corn | — | — | May 8 – May 22 | — |
| Sweet Potatoes | — | May 15 – Jun 5 | — | — |
| Garlic | — | — | — | Sep 29 – Nov 3 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Thorne Bay, AK weather station, 3 km away (elevation 285 ft (87 m)).
Frost dates near Thorne Bay
- Meyers Chuck May 1 · Oct 13
- Coffman Cove May 1 · Oct 13
- Klawock Apr 29 · Oct 16
- Craig Apr 14 · Nov 1
- Hydaburg Apr 14 · Nov 1
- Ward Cove Apr 4 · Nov 9
- Ketchikan Apr 4 · Nov 9
- Metlakatla Apr 14 · Oct 25
- Wrangell Apr 11 · Nov 1
- Point Baker Apr 19 · Oct 25
Frequently asked questions
When is the last frost in Thorne Bay, AK?
The median last spring frost in Thorne Bay, AK is May 1. There is still about a 10% chance of frost after May 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Thorne Bay, AK?
The median first fall frost is October 13, with about a 10% chance of frost before October 1.
How long is the growing season in Thorne Bay, AK?
About 165 days between the median last spring frost and first fall frost.
What planting zone is Thorne Bay, AK?
Thorne Bay, AK is in USDA hardiness zone 7b.