Frost dates for 99709Fairbanks, AK
The average last spring frost in Fairbanks is May 16 and the average first fall frost is September 8, giving a typical growing season of about 114 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 8
- Growing season
- 114 days
Safer after May 30 (1-in-10 risk)
Possible by Aug 26 (1-in-10 risk)
Last frost typically in 202 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 16 · May 29 · Jun 11 | Aug 13 · Aug 27 · Sep 10 | 90 days | 100% |
| Frost / freeze (32°F) | May 5 · May 16 · May 30 | Aug 26 · Sep 8 · Sep 21 | 114 days | 100% |
| Hard freeze (28°F) | Apr 26 · May 7 · May 20 | Sep 5 · Sep 20 · Oct 2 | 136 days | 100% |
Planting calendar for Fairbanks
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – May 19 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – May 29 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jun 21 |
| Sweet corn | Sow outdoors | Jun 1 – May 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 9 – May 19 |
| Broccoli | Transplant outdoors (fall) | Jun 8 – Jun 19 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | Apr 29 – May 29 |
| Cabbage | Transplant outdoors (fall) | May 29 – Jun 29 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | May 29 – Jul 15 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jun 15 – Jul 20 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | May 29 – Jul 30 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | May 22 – Jun 29 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | Apr 29 – Jun 14 |
| Garlic | Plant outdoors (fall) | Aug 29 – Sep 29 |
Where these dates come from
ZIP code 99709 is matched to the NOAA station University Exp Stn, AK, 0.7 km away, at 475 ft elevation (16 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| University Exp Stn, AK (used) | 475 ft | May 16 | Sep 8 |
| College Obsy, AK | 597 ft | May 18 | Sep 6 |
| Fairbanks Midtown, AK | 440 ft | May 13 | Sep 10 |
| Fairbanks Ap #2, AK | 427 ft | May 16 | Sep 8 |
Frost dates near Fairbanks
- Fairbanks, AK 99775 · last May 18, first Sep 6
- Fort Wainwright, AK 99703 · last May 16, first Sep 6
- Ester, AK 99725 · last May 15, first Sep 16
- North Pole, AK 99705 · last May 18, first Sep 5
- Eielson Afb, AK 99702 · last May 20, first Sep 1
- Two Rivers, AK 99716 · last May 30, first Sep 2
- Salcha, AK 99714 · last May 20, first Sep 1
- Nenana, AK 99760 · last May 15, first Sep 11
Frequently asked questions
- When is the last frost in Fairbanks, AK?
- For ZIP code 99709, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the University Exp Stn, AK weather station. There is a 1-in-10 chance of a frost after May 30.
- When is the first frost in Fairbanks, AK?
- The average first fall frost (32°F) is September 8. There is a 1-in-10 chance of frost by August 26, so tender plants are at risk from that point on.
- How long is the growing season in 99709?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 114 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.