Cooper Landing, AK frost dates
Last spring frostJun 12median date
First fall frostSep 1median date
Growing season81 daysfrost-free
Hardiness zone5aZone 5a
How Cooper Landing compares
- In 8 years out of 10, the last spring frost in Cooper Landing falls between May 29 and July 2, a 34-day window. The first fall frost falls between August 14 and September 17.
- The median last frost is 22 days later than the Alaska median of May 21.
- Its 81-day growing season is among the shortest of the 165 Alaska places with a regular frost season.
- The last frost is 40 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 219 nights a year at or below 32°F.
- Compared with Anchorage, AK, 78 km away, the last frost here is 15 days later than there and the growing season is 26 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 29 |
| 50% (median) | June 12 |
| 10% (safe for tender plants) | July 2 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 14 |
| 50% (median) | September 1 |
| 90% (late) | September 17 |
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 Cooper Landing, AK
Cooper Landing, AK frost dates — last frost Jun 12, first frost Sep 1, zone 5a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 20 to Apr 3Transplant outside: May 15 to May 29
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 26 to Jul 10
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 26 to Jul 10
Start indoors: Apr 17 to May 1Transplant outside: Jun 19 to Jul 3
Start indoors: Apr 17 to May 1Transplant outside: May 22 to Jun 5Sow outdoors: May 15 to Jun 19Plant for fall: Jul 7 to Aug 4
Start indoors: Apr 17 to May 1Transplant outside: May 15 to May 29Sow outdoors: May 15 to May 29
Start indoors: Apr 17 to May 1Transplant outside: May 29 to Jun 12
Start indoors: Apr 17 to May 1Transplant outside: May 22 to Jun 5
Start indoors: Apr 17 to May 1Transplant outside: May 29 to Jun 12
Start indoors: May 1 to May 15Transplant outside: Jul 3 to Jul 17Sow outdoors: Jul 3 to Jul 17
Start indoors: May 1 to May 15Transplant outside: Jun 19 to Jul 3
Sow outdoors: May 1 to May 22
Sow outdoors: May 1 to May 22Plant for fall: Jul 7 to Jul 28
Sow outdoors: May 8 to Jun 19Plant for fall: Jul 21 to Aug 11
Start indoors: May 15 to May 22Transplant outside: Jun 26 to Jul 3Sow outdoors: Jun 19 to Jul 3
Start indoors: May 15 to May 22Sow outdoors: Jun 19 to Jul 3
Start indoors: May 15 to May 22Sow outdoors: Jun 19 to Jul 3
Start indoors: May 15 to May 22Transplant outside: Jun 26 to Jul 10
Sow outdoors: May 22 to Jun 19
Sow outdoors: May 22 to Jun 19
Sow outdoors: May 22 to Jun 12
Sow outdoors: May 29 to Jun 26
Sow outdoors: May 29 to Jun 19Plant for fall: Jul 7 to Jul 28
Sow outdoors: Jun 19 to Jul 10
Sow outdoors: Jun 19 to Jul 3
Transplant outside: Jun 26 to Jul 17
Plant for fall: Aug 18 to Sep 22
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Cooper Landing, AK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 20 – Apr 3 | May 15 – May 29 | — | — |
| Peppers Warning: Your frost-free season is about 81 days, which is tight for peppers (75+ days). Choose early varieties and use transplants or row covers. | Apr 3 – Apr 17 | Jun 26 – Jul 10 | — | — |
| Eggplant Warning: Your frost-free season is about 81 days, which is tight for eggplant (75+ days). Choose early varieties and use transplants or row covers. | Apr 3 – Apr 17 | Jun 26 – Jul 10 | — | — |
| Tomatoes Warning: Your frost-free season is about 81 days, which is tight for tomatoes (70+ days). Choose early varieties and use transplants or row covers. | Apr 17 – May 1 | Jun 19 – Jul 3 | — | — |
| Lettuce | Apr 17 – May 1 | May 22 – Jun 5 | May 15 – Jun 19 | Jul 7 – Aug 4 |
| Kale | Apr 17 – May 1 | May 15 – May 29 | May 15 – May 29 | — |
| Broccoli | Apr 17 – May 1 | May 29 – Jun 12 | — | — |
| Cabbage | Apr 17 – May 1 | May 22 – Jun 5 | — | — |
| Cauliflower | Apr 17 – May 1 | May 29 – Jun 12 | — | — |
| Okra | May 1 – May 15 | Jul 3 – Jul 17 | Jul 3 – Jul 17 | — |
| Basil | May 1 – May 15 | Jun 19 – Jul 3 | — | — |
| Peas | — | — | May 1 – May 22 | — |
| Spinach | — | — | May 1 – May 22 | Jul 7 – Jul 28 |
| Radishes | — | — | May 8 – Jun 19 | Jul 21 – Aug 11 |
| Cucumbers | May 15 – May 22 | Jun 26 – Jul 3 | Jun 19 – Jul 3 | — |
| Zucchini & Summer Squash | May 15 – May 22 | — | Jun 19 – Jul 3 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 81 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 15 – May 22 | — | Jun 19 – Jul 3 | — |
| Melons & Watermelon Warning: Your frost-free season is about 81 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 15 – May 22 | Jun 26 – Jul 10 | — | — |
| Carrots | — | — | May 22 – Jun 19 | — |
| Beets | — | — | May 22 – Jun 19 | — |
| Potatoes | — | — | May 22 – Jun 12 | — |
| Swiss Chard | — | — | May 29 – Jun 26 | — |
| Cilantro | — | — | May 29 – Jun 19 | Jul 7 – Jul 28 |
| Green Beans | — | — | Jun 19 – Jul 10 | — |
| Sweet Corn Warning: Your frost-free season is about 81 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 19 – Jul 3 | — |
| Sweet Potatoes Warning: Your frost-free season is about 81 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 26 – Jul 17 | — | — |
| Garlic | — | — | — | Aug 18 – Sep 22 |
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 Cooper Landing 5 W, AK weather station, 8 km away (elevation 374 ft (114 m)).
Frost dates near Cooper Landing
- Moose Pass May 31 · Sep 8
- Seward May 2 · Oct 7
- Hope May 18 · Sep 24
- Sterling May 20 · Sep 21
- Girdwood May 8 · Sep 29
- Whittier Apr 25 · Oct 14
- Soldotna Jun 11 · Sep 1
- Indian May 18 · Sep 23
- Anchorage May 28 · Sep 12
- Kenai May 24 · Sep 12
Frequently asked questions
When is the last frost in Cooper Landing, AK?
The median last spring frost in Cooper Landing, AK is June 12. There is still about a 10% chance of frost after July 2, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Cooper Landing, AK?
The median first fall frost is September 1, with about a 10% chance of frost before August 14.
How long is the growing season in Cooper Landing, AK?
About 81 days between the median last spring frost and first fall frost.
What planting zone is Cooper Landing, AK?
Cooper Landing, AK is in USDA hardiness zone 5a.