Frost dates for 99743Healy, AK
The average last spring frost in Healy is May 27 and the average first fall frost is September 1, giving a typical growing season of about 97 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 27
- Average first fall frost
- Sep 1
- Growing season
- 97 days
Safer after Jun 10 (1-in-10 risk)
Possible by Aug 18 (1-in-10 risk)
Last frost typically in 212 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 27 · Jun 8 · Jun 27 | Aug 8 · Aug 22 · Sep 6 | 73 days | 100% |
| Frost / freeze (32°F) | May 11 · May 27 · Jun 10 | Aug 18 · Sep 1 · Sep 19 | 97 days | 100% |
| Hard freeze (28°F) | Apr 30 · May 12 · May 30 | Aug 27 · Sep 13 · Sep 29 | 121 days | 100% |
Planting calendar for Healy
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 26 – Jul 2 |
| Tomatoes | Transplant outdoors | Jun 12 – May 12 |
| Peppers | Start seeds indoors | Apr 26 – May 27 |
| Peppers | Transplant outdoors | Jun 26 – Jul 27 |
| Eggplant | Start seeds indoors | May 13 – Jun 11 |
| Eggplant | Transplant outdoors | Jun 26 – Jul 27 |
| Cucumbers | Sow outdoors | Jun 26 – May 22 |
| Summer squash | Sow outdoors | Jun 12 – Jul 27 |
| Winter squash & pumpkins | Sow outdoors | Jun 26 – Jul 27 |
| Snap beans | Sow outdoors | Jun 12 – Jun 14 |
| Sweet corn | Sow outdoors | Jun 12 – May 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 26 – Jul 27 |
| Okra | Sow outdoors | Jun 19 – Jul 12 |
| Peas | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Potatoes | Plant outdoors (spring) | Apr 26 – Jun 26 |
| Onions | Start seeds indoors (spring) | Mar 15 – Apr 11 |
| Onions | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (spring) | Apr 8 – May 12 |
| Broccoli | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (fall) | May 2 – May 12 |
| Broccoli | Transplant outdoors (fall) | Jun 1 – Jun 12 |
| Cabbage | Start seeds indoors (spring) | Mar 29 – Apr 26 |
| Cabbage | Transplant outdoors (spring) | Apr 26 – May 27 |
| Cabbage | Start seeds indoors (fall) | Apr 22 – May 22 |
| Cabbage | Transplant outdoors (fall) | May 22 – Jun 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 26 – Jul 12 |
| Leaf lettuce | Sow outdoors (fall) | May 22 – Jul 8 |
| Spinach | Sow outdoors (spring) | Apr 19 – Jun 2 |
| Spinach | Sow outdoors (fall) | Jun 8 – Jul 13 |
| Radishes | Sow outdoors (spring) | Apr 26 – Jun 16 |
| Radishes | Sow outdoors (fall) | May 22 – Jul 23 |
| Kale | Sow outdoors (spring) | May 13 – Jun 2 |
| Kale | Sow outdoors (fall) | May 15 – Jun 22 |
| Carrots | Sow outdoors (spring) | May 27 – Jul 12 |
| Carrots | Sow outdoors (fall) | Apr 22 – Jun 7 |
| Garlic | Plant outdoors (fall) | Aug 22 – Sep 22 |
Where these dates come from
ZIP code 99743 is matched to the NOAA station Healy, AK, 5.6 km away, at 1,417 ft elevation (157 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Healy, AK (used) | 1,417 ft | May 27 | Sep 1 |
| Mckinley Park, AK | 2,070 ft | Jun 6 | Aug 25 |
| Kobe Hill, AK | 800 ft | May 24 | Sep 2 |
| Clear Sky, AK | 646 ft | May 24 | Sep 4 |
Frost dates near Healy
- Clear, AK 99704 · last May 24, first Sep 4
- Anderson, AK 99744 · last May 15, first Sep 11
- Cantwell, AK 99729 · last —, first —
- Denali National Park, AK 99755 · last May 25, first Sep 8
- Nenana, AK 99760 · last May 15, first Sep 11
- Ester, AK 99725 · last May 15, first Sep 16
- Fairbanks, AK 99706 · last May 18, first Sep 6
Frequently asked questions
- When is the last frost in Healy, AK?
- For ZIP code 99743, the average last spring frost (32°F) is May 27, based on NOAA 1991-2020 climate normals for the Healy, AK weather station. There is a 1-in-10 chance of a frost after June 10.
- When is the first frost in Healy, AK?
- The average first fall frost (32°F) is September 1. 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 99743?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 97 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.