Port Alexander, AK frost dates
Last spring frostApr 18median date
First fall frostNov 5median date
Growing season201 daysfrost-free
Hardiness zone8aZone 8a
How Port Alexander compares
- In 8 years out of 10, the last spring frost in Port Alexander falls between March 31 and May 5, a 35-day window. The first fall frost falls between October 16 and November 25.
- The median last frost is 33 days earlier than the Alaska median of May 21.
- Its 201-day growing season is longer than 96% of the 165 Alaska places with a regular frost season (state median 124 days).
- The last frost is 20 days later than the zone 8a median of Mar 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 8a chart.
- The weather station records an average of 68 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 31 |
| 50% (median) | April 18 |
| 10% (safe for tender plants) | May 5 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 16 |
| 50% (median) | November 5 |
| 90% (late) | November 25 |
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 Port Alexander, AK
Port Alexander, AK frost dates — last frost Apr 18, first frost Nov 5, zone 8a. whenisthelastfrost.com
Crop
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Start indoors: Jan 24 to Feb 7Transplant outside: Mar 21 to Apr 4
Start indoors: Feb 7 to Feb 21Transplant outside: May 2 to May 16
Start indoors: Feb 7 to Feb 21Transplant outside: May 2 to May 16
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 25 to May 9
Start indoors: Feb 21 to Mar 7Transplant outside: Mar 28 to Apr 11Sow outdoors: Mar 21 to Apr 25Plant for fall: Sep 10 to Oct 8
Start indoors: Feb 21 to Mar 7Transplant outside: Mar 21 to Apr 4Sow outdoors: Mar 21 to Apr 4Plant for fall: Aug 27 to Sep 17
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 4 to Apr 18Plant for fall: Jul 30 to Aug 20
Start indoors: Feb 21 to Mar 7Transplant outside: Mar 28 to Apr 11Plant for fall: Jul 30 to Aug 20
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 4 to Apr 18Plant for fall: Jul 30 to Aug 20
Start indoors: Mar 7 to Mar 21Transplant outside: May 9 to May 23Sow outdoors: May 9 to May 23
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 25 to May 9
Sow outdoors: Mar 7 to Mar 28Plant for fall: Aug 13 to Sep 3
Sow outdoors: Mar 7 to Mar 28Plant for fall: Sep 10 to Oct 1
Sow outdoors: Mar 14 to Apr 25Plant for fall: Sep 24 to Oct 15
Start indoors: Mar 21 to Mar 28Transplant outside: May 2 to May 9Sow outdoors: Apr 25 to May 9Plant for fall: Aug 20 to Sep 3
Start indoors: Mar 21 to Mar 28Sow outdoors: Apr 25 to May 9Plant for fall: Aug 27 to Sep 10
Start indoors: Mar 21 to Mar 28Sow outdoors: Apr 25 to May 9
Start indoors: Mar 21 to Mar 28Transplant outside: May 2 to May 16
Sow outdoors: Mar 28 to Apr 25Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 28 to Apr 25Plant for fall: Aug 27 to Sep 10
Sow outdoors: Mar 28 to Apr 18
Sow outdoors: Apr 4 to May 2Plant for fall: Aug 27 to Sep 10
Sow outdoors: Apr 4 to Apr 25Plant for fall: Sep 10 to Oct 1
Sow outdoors: Apr 25 to May 16Plant for fall: Aug 20 to Sep 3
Sow outdoors: Apr 25 to May 9
Transplant outside: May 2 to May 23
Plant for fall: Oct 22 to Nov 26
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Port Alexander, AK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 24 – Feb 7 | Mar 21 – Apr 4 | — | — |
| Peppers | Feb 7 – Feb 21 | May 2 – May 16 | — | — |
| Eggplant | Feb 7 – Feb 21 | May 2 – May 16 | — | — |
| Tomatoes | Feb 21 – Mar 7 | Apr 25 – May 9 | — | — |
| Lettuce | Feb 21 – Mar 7 | Mar 28 – Apr 11 | Mar 21 – Apr 25 | Sep 10 – Oct 8 |
| Kale | Feb 21 – Mar 7 | Mar 21 – Apr 4 | Mar 21 – Apr 4 | Aug 27 – Sep 17 |
| Broccoli | Feb 21 – Mar 7 | Apr 4 – Apr 18 | — | Jul 30 – Aug 20 |
| Cabbage | Feb 21 – Mar 7 | Mar 28 – Apr 11 | — | Jul 30 – Aug 20 |
| Cauliflower | Feb 21 – Mar 7 | Apr 4 – Apr 18 | — | Jul 30 – Aug 20 |
| Okra | Mar 7 – Mar 21 | May 9 – May 23 | May 9 – May 23 | — |
| Basil | Mar 7 – Mar 21 | Apr 25 – May 9 | — | — |
| Peas | — | — | Mar 7 – Mar 28 | Aug 13 – Sep 3 |
| Spinach | — | — | Mar 7 – Mar 28 | Sep 10 – Oct 1 |
| Radishes | — | — | Mar 14 – Apr 25 | Sep 24 – Oct 15 |
| Cucumbers | Mar 21 – Mar 28 | May 2 – May 9 | Apr 25 – May 9 | Aug 20 – Sep 3 |
| Zucchini & Summer Squash | Mar 21 – Mar 28 | — | Apr 25 – May 9 | Aug 27 – Sep 10 |
| Winter Squash & Pumpkins | Mar 21 – Mar 28 | — | Apr 25 – May 9 | — |
| Melons & Watermelon | Mar 21 – Mar 28 | May 2 – May 16 | — | — |
| Carrots | — | — | Mar 28 – Apr 25 | Aug 13 – Aug 27 |
| Beets | — | — | Mar 28 – Apr 25 | Aug 27 – Sep 10 |
| Potatoes | — | — | Mar 28 – Apr 18 | — |
| Swiss Chard | — | — | Apr 4 – May 2 | Aug 27 – Sep 10 |
| Cilantro | — | — | Apr 4 – Apr 25 | Sep 10 – Oct 1 |
| Green Beans | — | — | Apr 25 – May 16 | Aug 20 – Sep 3 |
| Sweet Corn | — | — | Apr 25 – May 9 | — |
| Sweet Potatoes | — | May 2 – May 23 | — | — |
| Garlic | — | — | — | Oct 22 – Nov 26 |
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 Port Alexander, AK weather station, about 1 km away (elevation 13 ft (4 m)).
Frost dates near Port Alexander
- Point Baker Apr 19 · Oct 25
- Kake Apr 29 · Oct 25
- Sitka May 3 · Oct 18
- Petersburg Apr 29 · Oct 17
- Coffman Cove May 1 · Oct 13
- Klawock Apr 29 · Oct 16
- Craig Apr 14 · Nov 1
- Angoon Apr 29 · Oct 25
- Wrangell Apr 11 · Nov 1
- Thorne Bay May 1 · Oct 13
Frequently asked questions
When is the last frost in Port Alexander, AK?
The median last spring frost in Port Alexander, AK is April 18. There is still about a 10% chance of frost after May 5, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Port Alexander, AK?
The median first fall frost is November 5, with about a 10% chance of frost before October 16.
How long is the growing season in Port Alexander, AK?
About 201 days between the median last spring frost and first fall frost.
What planting zone is Port Alexander, AK?
Port Alexander, AK is in USDA hardiness zone 8a.