Frost dates for 99730Central, AK
The average last spring frost in Central is May 25 and the average first fall frost is August 26, giving a typical growing season of about 92 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 25
- Average first fall frost
- Aug 26
- Growing season
- 92 days
Safer after Jun 6 (1-in-10 risk)
Possible by Aug 12 (1-in-10 risk)
Last frost typically in 210 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) | — | — | 66 days | 100% |
| Frost / freeze (32°F) | May 12 · May 25 · Jun 6 | Aug 12 · Aug 26 · Sep 7 | 92 days | 100% |
| Hard freeze (28°F) | May 5 · May 14 · May 28 | Aug 23 · Sep 5 · Sep 18 | 113 days | 100% |
Planting calendar for Central
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 6 |
| 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 16 |
| Summer squash | Sow outdoors | Jun 10 – Jul 25 |
| Winter squash & pumpkins | Sow outdoors | Jun 24 – Jul 25 |
| Snap beans | Sow outdoors | Jun 10 – Jun 8 |
| Sweet corn | Sow outdoors | Jun 10 – May 6 |
| 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) | Apr 26 – May 6 |
| Broccoli | Transplant outdoors (fall) | May 26 – Jun 6 |
| Cabbage | Start seeds indoors (spring) | Mar 27 – Apr 24 |
| Cabbage | Transplant outdoors (spring) | Apr 24 – May 25 |
| Cabbage | Start seeds indoors (fall) | Apr 16 – May 16 |
| Cabbage | Transplant outdoors (fall) | May 16 – Jun 16 |
| Leaf lettuce | Sow outdoors (spring) | Apr 24 – Jul 10 |
| Leaf lettuce | Sow outdoors (fall) | May 16 – Jul 2 |
| Spinach | Sow outdoors (spring) | Apr 17 – May 31 |
| Spinach | Sow outdoors (fall) | Jun 2 – Jul 7 |
| Radishes | Sow outdoors (spring) | Apr 24 – Jun 14 |
| Radishes | Sow outdoors (fall) | May 16 – Jul 17 |
| Kale | Sow outdoors (spring) | May 11 – May 31 |
| Kale | Sow outdoors (fall) | May 9 – Jun 16 |
| Carrots | Sow outdoors (spring) | May 25 – Jul 10 |
| Carrots | Sow outdoors (fall) | Apr 16 – Jun 1 |
| Garlic | Plant outdoors (fall) | Aug 16 – Sep 16 |
Where these dates come from
ZIP code 99730 is matched to the NOAA station Central #2, AK, 11 km away, at 920 ft elevation (606 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Central #2, AK (used) | 920 ft | May 25 | Aug 26 |
| Circle Hot Springs, AK | 860 ft | — | — |
| Mile 42 Steese, AK | 960 ft | May 28 | Aug 26 |
| Two Rivers, AK | 605 ft | May 30 | Sep 2 |
Frost dates near Central
- Circle, AK 99733 · last May 25, first Aug 26
Frequently asked questions
- When is the last frost in Central, AK?
- For ZIP code 99730, the average last spring frost (32°F) is May 25, based on NOAA 1991-2020 climate normals for the Central #2, AK weather station. There is a 1-in-10 chance of a frost after June 6.
- When is the first frost in Central, AK?
- The average first fall frost (32°F) is August 26. There is a 1-in-10 chance of frost by August 12, so tender plants are at risk from that point on.
- How long is the growing season in 99730?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 92 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.