Circle, AK frost dates
Last spring frostMay 25median date
First fall frostAug 26median date
Growing season93 daysfrost-free
Hardiness zone1aZone 1a
How Circle compares
- In 8 years out of 10, the last spring frost in Circle falls between May 12 and June 6, a 25-day window. The first fall frost falls between August 12 and September 7.
- The median last frost is 4 days later than the Alaska median of May 21.
- Its 93-day growing season is longer than 8% of the 165 Alaska places with a regular frost season (state median 124 days).
- The weather station records an average of 254 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 12 |
| 50% (median) | May 25 |
| 10% (safe for tender plants) | June 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 12 |
| 50% (median) | August 26 |
| 90% (late) | September 7 |
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 Circle, AK
Circle, AK frost dates — last frost May 25, first frost Aug 26, zone 1a. whenisthelastfrost.com
Crop
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Start indoors: Mar 2 to Mar 16Transplant outside: Apr 27 to May 11
Start indoors: Mar 16 to Mar 30Transplant outside: Jun 8 to Jun 22
Start indoors: Mar 16 to Mar 30Transplant outside: Jun 8 to Jun 22
Start indoors: Mar 30 to Apr 13Transplant outside: Jun 1 to Jun 15
Start indoors: Mar 30 to Apr 13Transplant outside: May 4 to May 18Sow outdoors: Apr 27 to Jun 1Plant for fall: Jul 1 to Jul 29
Start indoors: Mar 30 to Apr 13Transplant outside: Apr 27 to May 11Sow outdoors: Apr 27 to May 11Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 30 to Apr 13Transplant outside: May 11 to May 25
Start indoors: Mar 30 to Apr 13Transplant outside: May 4 to May 18
Start indoors: Mar 30 to Apr 13Transplant outside: May 11 to May 25
Start indoors: Apr 13 to Apr 27Transplant outside: Jun 15 to Jun 29Sow outdoors: Jun 15 to Jun 29
Start indoors: Apr 13 to Apr 27Transplant outside: Jun 1 to Jun 15
Sow outdoors: Apr 13 to May 4
Sow outdoors: Apr 13 to May 4Plant for fall: Jul 1 to Jul 22
Sow outdoors: Apr 20 to Jun 1Plant for fall: Jul 15 to Aug 5
Start indoors: Apr 27 to May 4Transplant outside: Jun 8 to Jun 15Sow outdoors: Jun 1 to Jun 15
Start indoors: Apr 27 to May 4Sow outdoors: Jun 1 to Jun 15
Start indoors: Apr 27 to May 4Sow outdoors: Jun 1 to Jun 15
Start indoors: Apr 27 to May 4Transplant outside: Jun 8 to Jun 22
Sow outdoors: May 4 to Jun 1
Sow outdoors: May 4 to Jun 1Plant for fall: Jun 17 to Jul 1
Sow outdoors: May 4 to May 25
Sow outdoors: May 11 to Jun 8
Sow outdoors: May 11 to Jun 1Plant for fall: Jul 1 to Jul 22
Sow outdoors: Jun 1 to Jun 22
Sow outdoors: Jun 1 to Jun 15
Transplant outside: Jun 8 to Jun 29
Plant for fall: Aug 12 to Sep 16
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Circle, AK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 2 – Mar 16 | Apr 27 – May 11 | — | — |
| Peppers | Mar 16 – Mar 30 | Jun 8 – Jun 22 | — | — |
| Eggplant | Mar 16 – Mar 30 | Jun 8 – Jun 22 | — | — |
| Tomatoes | Mar 30 – Apr 13 | Jun 1 – Jun 15 | — | — |
| Lettuce | Mar 30 – Apr 13 | May 4 – May 18 | Apr 27 – Jun 1 | Jul 1 – Jul 29 |
| Kale | Mar 30 – Apr 13 | Apr 27 – May 11 | Apr 27 – May 11 | Jun 17 – Jul 8 |
| Broccoli | Mar 30 – Apr 13 | May 11 – May 25 | — | — |
| Cabbage | Mar 30 – Apr 13 | May 4 – May 18 | — | — |
| Cauliflower | Mar 30 – Apr 13 | May 11 – May 25 | — | — |
| Okra | Apr 13 – Apr 27 | Jun 15 – Jun 29 | Jun 15 – Jun 29 | — |
| Basil | Apr 13 – Apr 27 | Jun 1 – Jun 15 | — | — |
| Peas | — | — | Apr 13 – May 4 | — |
| Spinach | — | — | Apr 13 – May 4 | Jul 1 – Jul 22 |
| Radishes | — | — | Apr 20 – Jun 1 | Jul 15 – Aug 5 |
| Cucumbers | Apr 27 – May 4 | Jun 8 – Jun 15 | Jun 1 – Jun 15 | — |
| Zucchini & Summer Squash | Apr 27 – May 4 | — | Jun 1 – Jun 15 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 93 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | Apr 27 – May 4 | — | Jun 1 – Jun 15 | — |
| Melons & Watermelon Warning: Your frost-free season is about 93 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | Apr 27 – May 4 | Jun 8 – Jun 22 | — | — |
| Carrots | — | — | May 4 – Jun 1 | — |
| Beets | — | — | May 4 – Jun 1 | Jun 17 – Jul 1 |
| Potatoes | — | — | May 4 – May 25 | — |
| Swiss Chard | — | — | May 11 – Jun 8 | — |
| Cilantro | — | — | May 11 – Jun 1 | Jul 1 – Jul 22 |
| Green Beans | — | — | Jun 1 – Jun 22 | — |
| Sweet Corn Warning: Your frost-free season is about 93 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 1 – Jun 15 | — |
| Sweet Potatoes Warning: Your frost-free season is about 93 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 8 – Jun 29 | — | — |
| Garlic | — | — | — | Aug 12 – Sep 16 |
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 Central #2, AK weather station, 42 km away (elevation 919 ft (280 m)). That is far enough away that your dates may differ, especially if your elevation is different.
Frost dates near Circle
- Central frost any month
- Chalkyitsik May 25 · Aug 26
- Fort Yukon May 25 · Aug 26
- Beaver May 28 · Aug 26
- Venetie frost any month
- Two Rivers May 30 · Sep 2
- Eagle May 29 · Aug 23
- Eielson Afb May 20 · Sep 1
- North Pole May 22 · Sep 2
- Salcha May 20 · Sep 1
Frequently asked questions
When is the last frost in Circle, AK?
The median last spring frost in Circle, AK is May 25. There is still about a 10% chance of frost after June 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Circle, AK?
The median first fall frost is August 26, with about a 10% chance of frost before August 12.
How long is the growing season in Circle, AK?
About 93 days between the median last spring frost and first fall frost.
What planting zone is Circle, AK?
Circle, AK is in USDA hardiness zone 1a.