Frost dates for 99706Fairbanks, AK
The average last spring frost in Fairbanks is May 18 and the average first fall frost is September 6, 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 6
- 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 17 · May 31 · Jun 16 | Aug 11 · Aug 26 · Sep 7 | 87 days | 100% |
| Frost / freeze (32°F) | May 7 · May 18 · Jun 1 | Aug 24 · Sep 6 · Sep 20 | 111 days | 100% |
| Hard freeze (28°F) | Apr 26 · May 7 · May 22 | Sep 5 · Sep 20 · Oct 1 | 133 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 17 – Jun 23 |
| Tomatoes | Transplant outdoors | Jun 3 – May 17 |
| 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 27 |
| Summer squash | Sow outdoors | Jun 3 – Jul 18 |
| Winter squash & pumpkins | Sow outdoors | Jun 17 – Jul 18 |
| Snap beans | Sow outdoors | Jun 3 – Jun 19 |
| Sweet corn | Sow outdoors | Jun 3 – May 17 |
| 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 7 – May 17 |
| Broccoli | Transplant outdoors (fall) | Jun 6 – Jun 17 |
| Cabbage | Start seeds indoors (spring) | Mar 20 – Apr 17 |
| Cabbage | Transplant outdoors (spring) | Apr 17 – May 18 |
| Cabbage | Start seeds indoors (fall) | Apr 27 – May 27 |
| Cabbage | Transplant outdoors (fall) | May 27 – Jun 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 17 – Jul 3 |
| Leaf lettuce | Sow outdoors (fall) | May 27 – Jul 13 |
| Spinach | Sow outdoors (spring) | Apr 10 – May 24 |
| Spinach | Sow outdoors (fall) | Jun 13 – Jul 18 |
| Radishes | Sow outdoors (spring) | Apr 17 – Jun 7 |
| Radishes | Sow outdoors (fall) | May 27 – Jul 28 |
| Kale | Sow outdoors (spring) | May 4 – May 24 |
| Kale | Sow outdoors (fall) | May 20 – Jun 27 |
| Carrots | Sow outdoors (spring) | May 18 – Jul 3 |
| Carrots | Sow outdoors (fall) | Apr 27 – Jun 12 |
| Garlic | Plant outdoors (fall) | Aug 27 – Sep 27 |
Where these dates come from
ZIP code 99706 is matched to the NOAA station College Obsy, AK, 4.3 km away, at 597 ft elevation (33 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| College Obsy, AK (used) | 597 ft | May 18 | Sep 6 |
| University Exp Stn, AK | 475 ft | May 16 | Sep 8 |
| Ester, AK | 655 ft | May 24 | Sep 1 |
| Fairbanks Ap #2, AK | 427 ft | May 16 | Sep 8 |
Frost dates near Fairbanks
- Fairbanks, AK 99709 · last May 16, first Sep 8
- Ester, AK 99725 · last May 15, first Sep 16
- Fort Wainwright, AK 99703 · last May 16, first Sep 6
- 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 99706, the average last spring frost (32°F) is May 18, based on NOAA 1991-2020 climate normals for the College Obsy, AK weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Fairbanks, AK?
- The average first fall frost (32°F) is September 6. 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 99706?
- 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.