Tyonek, AK frost dates
Last spring frostMay 18median date
First fall frostSep 22median date
Growing season127 daysfrost-free
Hardiness zone5aZone 5a
How Tyonek compares
- In 8 years out of 10, the last spring frost in Tyonek falls between May 5 and May 30, a 25-day window. The first fall frost falls between September 6 and October 5.
- The median last frost is 3 days earlier than the Alaska median of May 21.
- Its 127-day growing season is longer than 62% of the 165 Alaska places with a regular frost season (state median 124 days).
- The last frost is 15 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 209 nights a year at or below 32°F.
- Compared with Anchorage, AK, 70 km away, the last frost here is 10 days earlier than there and the growing season is 20 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 5 |
| 50% (median) | May 18 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 6 |
| 50% (median) | September 22 |
| 90% (late) | October 5 |
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 Tyonek, AK
Tyonek, AK frost dates — last frost May 18, first frost Sep 22, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Feb 23 to Mar 9Transplant outside: Apr 20 to May 4
Start indoors: Mar 9 to Mar 23Transplant outside: Jun 1 to Jun 15
Start indoors: Mar 9 to Mar 23Transplant outside: Jun 1 to Jun 15
Start indoors: Mar 23 to Apr 6Transplant outside: May 25 to Jun 8
Start indoors: Mar 23 to Apr 6Transplant outside: Apr 27 to May 11Sow outdoors: Apr 20 to May 25Plant for fall: Jul 28 to Aug 25
Start indoors: Mar 23 to Apr 6Transplant outside: Apr 20 to May 4Sow outdoors: Apr 20 to May 4Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 23 to Apr 6Transplant outside: May 4 to May 18Plant for fall: Jun 16 to Jul 7
Start indoors: Mar 23 to Apr 6Transplant outside: Apr 27 to May 11Plant for fall: Jun 16 to Jul 7
Start indoors: Mar 23 to Apr 6Transplant outside: May 4 to May 18Plant for fall: Jun 16 to Jul 7
Start indoors: Apr 6 to Apr 20Transplant outside: Jun 8 to Jun 22Sow outdoors: Jun 8 to Jun 22
Start indoors: Apr 6 to Apr 20Transplant outside: May 25 to Jun 8
Sow outdoors: Apr 6 to Apr 27Plant for fall: Jun 30 to Jul 21
Sow outdoors: Apr 6 to Apr 27Plant for fall: Jul 28 to Aug 18
Sow outdoors: Apr 13 to May 25Plant for fall: Aug 11 to Sep 1
Start indoors: Apr 20 to Apr 27Transplant outside: Jun 1 to Jun 8Sow outdoors: May 25 to Jun 8Plant for fall: Jul 7 to Jul 21
Start indoors: Apr 20 to Apr 27Sow outdoors: May 25 to Jun 8Plant for fall: Jul 14 to Jul 28
Start indoors: Apr 20 to Apr 27Sow outdoors: May 25 to Jun 8
Start indoors: Apr 20 to Apr 27Transplant outside: Jun 1 to Jun 15
Sow outdoors: Apr 27 to May 25Plant for fall: Jun 30 to Jul 14
Sow outdoors: Apr 27 to May 25Plant for fall: Jul 14 to Jul 28
Sow outdoors: Apr 27 to May 18
Sow outdoors: May 4 to Jun 1Plant for fall: Jul 14 to Jul 28
Sow outdoors: May 4 to May 25Plant for fall: Jul 28 to Aug 18
Sow outdoors: May 25 to Jun 15Plant for fall: Jul 7 to Jul 21
Sow outdoors: May 25 to Jun 8
Transplant outside: Jun 1 to Jun 22
Plant for fall: Sep 8 to Oct 13
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Tyonek, AK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 23 – Mar 9 | Apr 20 – May 4 | — | — |
| Peppers | Mar 9 – Mar 23 | Jun 1 – Jun 15 | — | — |
| Eggplant | Mar 9 – Mar 23 | Jun 1 – Jun 15 | — | — |
| Tomatoes | Mar 23 – Apr 6 | May 25 – Jun 8 | — | — |
| Lettuce | Mar 23 – Apr 6 | Apr 27 – May 11 | Apr 20 – May 25 | Jul 28 – Aug 25 |
| Kale | Mar 23 – Apr 6 | Apr 20 – May 4 | Apr 20 – May 4 | Jul 14 – Aug 4 |
| Broccoli | Mar 23 – Apr 6 | May 4 – May 18 | — | Jun 16 – Jul 7 |
| Cabbage | Mar 23 – Apr 6 | Apr 27 – May 11 | — | Jun 16 – Jul 7 |
| Cauliflower | Mar 23 – Apr 6 | May 4 – May 18 | — | Jun 16 – Jul 7 |
| Okra | Apr 6 – Apr 20 | Jun 8 – Jun 22 | Jun 8 – Jun 22 | — |
| Basil | Apr 6 – Apr 20 | May 25 – Jun 8 | — | — |
| Peas | — | — | Apr 6 – Apr 27 | Jun 30 – Jul 21 |
| Spinach | — | — | Apr 6 – Apr 27 | Jul 28 – Aug 18 |
| Radishes | — | — | Apr 13 – May 25 | Aug 11 – Sep 1 |
| Cucumbers | Apr 20 – Apr 27 | Jun 1 – Jun 8 | May 25 – Jun 8 | Jul 7 – Jul 21 |
| Zucchini & Summer Squash | Apr 20 – Apr 27 | — | May 25 – Jun 8 | Jul 14 – Jul 28 |
| Winter Squash & Pumpkins | Apr 20 – Apr 27 | — | May 25 – Jun 8 | — |
| Melons & Watermelon | Apr 20 – Apr 27 | Jun 1 – Jun 15 | — | — |
| Carrots | — | — | Apr 27 – May 25 | Jun 30 – Jul 14 |
| Beets | — | — | Apr 27 – May 25 | Jul 14 – Jul 28 |
| Potatoes | — | — | Apr 27 – May 18 | — |
| Swiss Chard | — | — | May 4 – Jun 1 | Jul 14 – Jul 28 |
| Cilantro | — | — | May 4 – May 25 | Jul 28 – Aug 18 |
| Green Beans | — | — | May 25 – Jun 15 | Jul 7 – Jul 21 |
| Sweet Corn | — | — | May 25 – Jun 8 | — |
| Sweet Potatoes | — | Jun 1 – Jun 22 | — | — |
| Garlic | — | — | — | Sep 8 – Oct 13 |
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 Kenai 9n, AK weather station, 45 km away (elevation 125 ft (38 m)). That is far enough away that your dates may differ, especially if your elevation is different.
Frost dates near Tyonek
- Nikiski May 18 · Sep 22
- Kenai May 24 · Sep 12
- Sterling May 20 · Sep 21
- Soldotna Jun 11 · Sep 1
- Anchorage May 28 · Sep 12
- Big Lake May 29 · Sep 7
- Kasilof Jun 11 · Sep 1
- Indian May 18 · Sep 23
- Eagle River May 9 · Sep 26
- Hope May 18 · Sep 24
Frequently asked questions
When is the last frost in Tyonek, AK?
The median last spring frost in Tyonek, AK is May 18. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Tyonek, AK?
The median first fall frost is September 22, with about a 10% chance of frost before September 6.
How long is the growing season in Tyonek, AK?
About 127 days between the median last spring frost and first fall frost.
What planting zone is Tyonek, AK?
Tyonek, AK is in USDA hardiness zone 5a.