Frost dates for 99753Koyuk, AK
The average last spring frost in Koyuk is May 25 and the average first fall frost is September 3, giving a typical growing season of about 101 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 25
- Average first fall frost
- Sep 3
- Growing season
- 101 days
Safer after Jun 11 (1-in-10 risk)
Possible by Aug 18 (1-in-10 risk)
Last frost typically in 203 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | — | — | 73 days | 100% |
| Frost / freeze (32°F) | May 10 · May 25 · Jun 11 | Aug 18 · Sep 3 · Sep 21 | 101 days | 100% |
| Hard freeze (28°F) | May 2 · May 12 · May 29 | Sep 1 · Sep 17 · Oct 2 | 125 days | 100% |
Planting calendar for Koyuk
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 24 – Jun 30 |
| Tomatoes | Transplant outdoors | Jun 10 – May 14 |
| Peppers | Start seeds indoors | Apr 24 – May 25 |
| Peppers | Transplant outdoors | Jun 24 – Jul 25 |
| Eggplant | Start seeds indoors | May 11 – Jun 9 |
| Eggplant | Transplant outdoors | Jun 24 – Jul 25 |
| Cucumbers | Sow outdoors | Jun 24 – May 24 |
| Summer squash | Sow outdoors | Jun 10 – Jul 25 |
| Winter squash & pumpkins | Sow outdoors | Jun 24 – Jul 25 |
| Snap beans | Sow outdoors | Jun 10 – Jun 16 |
| Sweet corn | Sow outdoors | Jun 10 – May 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 24 – Jul 25 |
| Okra | Sow outdoors | Jun 17 – Jul 10 |
| Peas | Sow outdoors (spring) | Apr 24 – Jun 9 |
| Potatoes | Plant outdoors (spring) | Apr 24 – Jun 24 |
| Onions | Start seeds indoors (spring) | Mar 13 – Apr 9 |
| Onions | Transplant outdoors (spring) | May 11 – Jun 9 |
| Broccoli | Start seeds indoors (spring) | Apr 6 – May 10 |
| Broccoli | Transplant outdoors (spring) | May 11 – Jun 9 |
| Broccoli | Start seeds indoors (fall) | May 4 – May 14 |
| Broccoli | Transplant outdoors (fall) | Jun 3 – Jun 14 |
| Cabbage | Start seeds indoors (spring) | Mar 27 – Apr 24 |
| Cabbage | Transplant outdoors (spring) | Apr 24 – May 25 |
| Cabbage | Start seeds indoors (fall) | Apr 24 – May 24 |
| Cabbage | Transplant outdoors (fall) | May 24 – Jun 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 24 – Jul 10 |
| Leaf lettuce | Sow outdoors (fall) | May 24 – Jul 10 |
| Spinach | Sow outdoors (spring) | Apr 17 – May 31 |
| Spinach | Sow outdoors (fall) | Jun 10 – Jul 15 |
| Radishes | Sow outdoors (spring) | Apr 24 – Jun 14 |
| Radishes | Sow outdoors (fall) | May 24 – Jul 25 |
| Kale | Sow outdoors (spring) | May 11 – May 31 |
| Kale | Sow outdoors (fall) | May 17 – Jun 24 |
| Carrots | Sow outdoors (spring) | May 25 – Jul 10 |
| Carrots | Sow outdoors (fall) | Apr 24 – Jun 9 |
| Garlic | Plant outdoors (fall) | Aug 24 – Sep 24 |
Where these dates come from
ZIP code 99753 is matched to the NOAA station Kaltag Ap, AK, 133.3 km away, at 181 ft elevation (158 ft higher than the ZIP code's center). This station is relatively far away, so local dates may differ more than usual. Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Kaltag Ap, AK (used) | 181 ft | May 25 | Sep 3 |
| Deering Ap, AK | 21 ft | — | — |
| Galena, AK | 152 ft | May 18 | Sep 8 |
| Nome Muni Ap, AK | 13 ft | Jun 5 | Sep 3 |
Frost dates near Koyuk
- Elim, AK 99739 · last Jun 5, first Sep 3
- Shaktoolik, AK 99771 · last May 25, first Sep 3
Frequently asked questions
- When is the last frost in Koyuk, AK?
- For ZIP code 99753, the average last spring frost (32°F) is May 25, based on NOAA 1991-2020 climate normals for the Kaltag Ap, AK weather station. There is a 1-in-10 chance of a frost after June 11.
- When is the first frost in Koyuk, AK?
- The average first fall frost (32°F) is September 3. There is a 1-in-10 chance of frost by August 18, so tender plants are at risk from that point on.
- How long is the growing season in 99753?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 101 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.