Delta Junction, AK frost dates
Last spring frostMay 17median date
First fall frostSep 7median date
Growing season113 daysfrost-free
Hardiness zone3aZone 3a
How Delta Junction compares
- In 8 years out of 10, the last spring frost in Delta Junction falls between May 3 and May 31, a 28-day window. The first fall frost falls between August 23 and September 22.
- The median last frost is 4 days earlier than the Alaska median of May 21.
- Its 113-day growing season is longer than 39% of the 165 Alaska places with a regular frost season (state median 124 days).
- The weather station records an average of 219 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 17 |
| 10% (safe for tender plants) | May 31 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 23 |
| 50% (median) | September 7 |
| 90% (late) | September 22 |
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 Delta Junction, AK
Delta Junction, AK frost dates — last frost May 17, first frost Sep 7, zone 3a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 19 to May 3
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Sow outdoors: Apr 19 to May 24Plant for fall: Jul 13 to Aug 10
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 19 to May 3Sow outdoors: Apr 19 to May 3Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 1 to Jun 22
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Plant for fall: Jun 1 to Jun 22
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 1 to Jun 22
Start indoors: Apr 5 to Apr 19Transplant outside: Jun 7 to Jun 21Sow outdoors: Jun 7 to Jun 21
Start indoors: Apr 5 to Apr 19Transplant outside: May 24 to Jun 7
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jun 15 to Jul 6
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jul 13 to Aug 3
Sow outdoors: Apr 12 to May 24Plant for fall: Jul 27 to Aug 17
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 7Sow outdoors: May 24 to Jun 7Plant for fall: Jun 22 to Jul 6
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7Plant for fall: Jun 29 to Jul 13
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 26 to May 24Plant for fall: Jun 15 to Jun 29
Sow outdoors: Apr 26 to May 24Plant for fall: Jun 29 to Jul 13
Sow outdoors: Apr 26 to May 17
Sow outdoors: May 3 to May 31Plant for fall: Jun 29 to Jul 13
Sow outdoors: May 3 to May 24Plant for fall: Jul 13 to Aug 3
Sow outdoors: May 24 to Jun 14
Sow outdoors: May 24 to Jun 7
Transplant outside: May 31 to Jun 21
Plant for fall: Aug 24 to Sep 28
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Delta Junction, AK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 22 – Mar 8 | Apr 19 – May 3 | — | — |
| Peppers | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Eggplant | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Tomatoes | Mar 22 – Apr 5 | May 24 – Jun 7 | — | — |
| Lettuce | Mar 22 – Apr 5 | Apr 26 – May 10 | Apr 19 – May 24 | Jul 13 – Aug 10 |
| Kale | Mar 22 – Apr 5 | Apr 19 – May 3 | Apr 19 – May 3 | Jun 29 – Jul 20 |
| Broccoli | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 1 – Jun 22 |
| Cabbage | Mar 22 – Apr 5 | Apr 26 – May 10 | — | Jun 1 – Jun 22 |
| Cauliflower | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 1 – Jun 22 |
| Okra | Apr 5 – Apr 19 | Jun 7 – Jun 21 | Jun 7 – Jun 21 | — |
| Basil | Apr 5 – Apr 19 | May 24 – Jun 7 | — | — |
| Peas | — | — | Apr 5 – Apr 26 | Jun 15 – Jul 6 |
| Spinach | — | — | Apr 5 – Apr 26 | Jul 13 – Aug 3 |
| Radishes | — | — | Apr 12 – May 24 | Jul 27 – Aug 17 |
| Cucumbers | Apr 19 – Apr 26 | May 31 – Jun 7 | May 24 – Jun 7 | Jun 22 – Jul 6 |
| Zucchini & Summer Squash | Apr 19 – Apr 26 | — | May 24 – Jun 7 | Jun 29 – Jul 13 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 113 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | Apr 19 – Apr 26 | — | May 24 – Jun 7 | — |
| Melons & Watermelon | Apr 19 – Apr 26 | May 31 – Jun 14 | — | — |
| Carrots | — | — | Apr 26 – May 24 | Jun 15 – Jun 29 |
| Beets | — | — | Apr 26 – May 24 | Jun 29 – Jul 13 |
| Potatoes | — | — | Apr 26 – May 17 | — |
| Swiss Chard | — | — | May 3 – May 31 | Jun 29 – Jul 13 |
| Cilantro | — | — | May 3 – May 24 | Jul 13 – Aug 3 |
| Green Beans | — | — | May 24 – Jun 14 | — |
| Sweet Corn | — | — | May 24 – Jun 7 | — |
| Sweet Potatoes Warning: Your frost-free season is about 113 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | May 31 – Jun 21 | — | — |
| Garlic | — | — | — | Aug 24 – Sep 28 |
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 Big Delta Ap, AK weather station, 5 km away (elevation 1,276 ft (389 m)).
Frost dates near Delta Junction
- Fort Greely May 26 · Sep 2
- Salcha May 20 · Sep 1
- Eielson Afb May 20 · Sep 1
- Two Rivers May 30 · Sep 2
- North Pole May 22 · Sep 2
- Fort Wainwright May 16 · Sep 6
- Fairbanks May 16 · Sep 6
- Tanacross frost any month
- Ester May 24 · Sep 1
- Tok Jun 3 · Aug 27
Frequently asked questions
When is the last frost in Delta Junction, AK?
The median last spring frost in Delta Junction, AK is May 17. There is still about a 10% chance of frost after May 31, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Delta Junction, AK?
The median first fall frost is September 7, with about a 10% chance of frost before August 23.
How long is the growing season in Delta Junction, AK?
About 113 days between the median last spring frost and first fall frost.
What planting zone is Delta Junction, AK?
Delta Junction, AK is in USDA hardiness zone 3a.