Frost dates for 99751Kobuk, AK
The average last spring frost in Kobuk is May 18 and the average first fall frost is September 8, giving a typical growing season of about 111 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 18
- Average first fall frost
- Sep 8
- Growing season
- 111 days
Safer after Jun 1 (1-in-10 risk)
Possible by Aug 24 (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) | May 18 · May 31 · Jun 16 | Aug 11 · Aug 27 · Sep 11 | 88 days | 100% |
| Frost / freeze (32°F) | May 8 · May 18 · Jun 1 | Aug 24 · Sep 8 · Sep 23 | 111 days | 100% |
| Hard freeze (28°F) | May 2 · May 10 · May 26 | Sep 3 · Sep 18 · Oct 3 | 129 days | 100% |
Planting calendar for Kobuk
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 17 – Jun 23 |
| Tomatoes | Transplant outdoors | Jun 3 – May 19 |
| Peppers | Start seeds indoors | Apr 17 – May 18 |
| Peppers | Transplant outdoors | Jun 17 – Jul 18 |
| Eggplant | Start seeds indoors | May 4 – Jun 2 |
| Eggplant | Transplant outdoors | Jun 17 – Jul 18 |
| Cucumbers | Sow outdoors | Jun 17 – May 29 |
| Summer squash | Sow outdoors | Jun 3 – Jul 18 |
| Winter squash & pumpkins | Sow outdoors | Jun 17 – Jul 18 |
| Snap beans | Sow outdoors | Jun 3 – Jun 21 |
| Sweet corn | Sow outdoors | Jun 3 – May 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 17 – Jul 18 |
| Okra | Sow outdoors | Jun 10 – Jul 3 |
| Peas | Sow outdoors (spring) | Apr 17 – Jun 2 |
| Potatoes | Plant outdoors (spring) | Apr 17 – Jun 17 |
| Onions | Start seeds indoors (spring) | Mar 6 – Apr 2 |
| Onions | Transplant outdoors (spring) | May 4 – Jun 2 |
| Broccoli | Start seeds indoors (spring) | Mar 30 – May 3 |
| Broccoli | Transplant outdoors (spring) | May 4 – Jun 2 |
| Broccoli | Start seeds indoors (fall) | May 9 – May 19 |
| Broccoli | Transplant outdoors (fall) | Jun 8 – Jun 19 |
| Cabbage | Start seeds indoors (spring) | Mar 20 – Apr 17 |
| Cabbage | Transplant outdoors (spring) | Apr 17 – May 18 |
| Cabbage | Start seeds indoors (fall) | Apr 29 – May 29 |
| Cabbage | Transplant outdoors (fall) | May 29 – Jun 29 |
| Leaf lettuce | Sow outdoors (spring) | Apr 17 – Jul 3 |
| Leaf lettuce | Sow outdoors (fall) | May 29 – Jul 15 |
| Spinach | Sow outdoors (spring) | Apr 10 – May 24 |
| Spinach | Sow outdoors (fall) | Jun 15 – Jul 20 |
| Radishes | Sow outdoors (spring) | Apr 17 – Jun 7 |
| Radishes | Sow outdoors (fall) | May 29 – Jul 30 |
| Kale | Sow outdoors (spring) | May 4 – May 24 |
| Kale | Sow outdoors (fall) | May 22 – Jun 29 |
| Carrots | Sow outdoors (spring) | May 18 – Jul 3 |
| Carrots | Sow outdoors (fall) | Apr 29 – Jun 14 |
| Garlic | Plant outdoors (fall) | Aug 29 – Sep 29 |
Where these dates come from
ZIP code 99751 is matched to the NOAA station Galena, AK, 240.9 km away, at 152 ft elevation (21 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 |
|---|---|---|---|
| Galena, AK (used) | 152 ft | May 18 | Sep 8 |
| Bettles Ap, AK | 642 ft | May 22 | Aug 24 |
| Kotzebue Ralph Wein Ap, AK | 30 ft | Jun 5 | Sep 24 |
| Deering Ap, AK | 21 ft | — | — |
Frost dates near Kobuk
- Shungnak, AK 99773 · last May 18, first Sep 8
- Ambler, AK 99786 · last Jun 5, first Sep 24
Frequently asked questions
- When is the last frost in Kobuk, AK?
- For ZIP code 99751, the average last spring frost (32°F) is May 18, based on NOAA 1991-2020 climate normals for the Galena, AK weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Kobuk, AK?
- The average first fall frost (32°F) is September 8. There is a 1-in-10 chance of frost by August 24, so tender plants are at risk from that point on.
- How long is the growing season in 99751?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 111 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.