Frost dates for 99702Eielson Afb, AK
The average last spring frost in Eielson Afb is May 20 and the average first fall frost is September 1, giving a typical growing season of about 104 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Sep 1
- Growing season
- 104 days
Safer after Jun 3 (1-in-10 risk)
Possible by Aug 20 (1-in-10 risk)
Last frost typically in 205 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 19 · May 31 · Jun 18 | Aug 10 · Aug 22 · Sep 2 | 82 days | 100% |
| Frost / freeze (32°F) | May 10 · May 20 · Jun 3 | Aug 20 · Sep 1 · Sep 16 | 104 days | 100% |
| Hard freeze (28°F) | May 1 · May 10 · May 25 | Sep 1 · Sep 14 · Sep 27 | 126 days | 100% |
Planting calendar for Eielson Afb
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 19 – Jun 25 |
| Tomatoes | Transplant outdoors | Jun 5 – May 12 |
| Peppers | Start seeds indoors | Apr 19 – May 20 |
| Peppers | Transplant outdoors | Jun 19 – Jul 20 |
| Eggplant | Start seeds indoors | May 6 – Jun 4 |
| Eggplant | Transplant outdoors | Jun 19 – Jul 20 |
| Cucumbers | Sow outdoors | Jun 19 – May 22 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jun 14 |
| Sweet corn | Sow outdoors | Jun 5 – May 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 19 – Jul 20 |
| Okra | Sow outdoors | Jun 12 – Jul 5 |
| Peas | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Potatoes | Plant outdoors (spring) | Apr 19 – Jun 19 |
| Onions | Start seeds indoors (spring) | Mar 8 – Apr 4 |
| Onions | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (spring) | Apr 1 – May 5 |
| Broccoli | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (fall) | May 2 – May 12 |
| Broccoli | Transplant outdoors (fall) | Jun 1 – Jun 12 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | Apr 22 – May 22 |
| Cabbage | Transplant outdoors (fall) | May 22 – Jun 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | May 22 – Jul 8 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jun 8 – Jul 13 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | May 22 – Jul 23 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | May 15 – Jun 22 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | Apr 22 – Jun 7 |
| Garlic | Plant outdoors (fall) | Aug 22 – Sep 22 |
Where these dates come from
ZIP code 99702 is matched to the NOAA station Eielson Fld, AK, 1.2 km away, at 547 ft elevation (6 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Eielson Fld, AK (used) | 547 ft | May 20 | Sep 1 |
| N Pole, AK | 475 ft | May 18 | Sep 5 |
| N Pole 1N, AK | 496 ft | May 22 | Sep 2 |
| Two Rivers, AK | 605 ft | May 30 | Sep 2 |
Frost dates near Eielson Afb
- North Pole, AK 99705 · last May 18, first Sep 5
- Salcha, AK 99714 · last May 20, first Sep 1
- Two Rivers, AK 99716 · last May 30, first Sep 2
- Fort Wainwright, AK 99703 · last May 16, first Sep 6
- Fairbanks, AK 99712 · last Jun 1, first Aug 28
- Ester, AK 99725 · last May 15, first Sep 16
- Fort Greely, AK 99731 · last May 17, first Sep 7
Frequently asked questions
- When is the last frost in Eielson Afb, AK?
- For ZIP code 99702, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Eielson Fld, AK weather station. There is a 1-in-10 chance of a frost after June 3.
- When is the first frost in Eielson Afb, AK?
- The average first fall frost (32°F) is September 1. There is a 1-in-10 chance of frost by August 20, so tender plants are at risk from that point on.
- How long is the growing season in 99702?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 104 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.