Frost dates for 99708Fairbanks, AK
The average last spring frost in Fairbanks is May 13 and the average first fall frost is September 15, giving a typical growing season of about 122 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 13
- Average first fall frost
- Sep 15
- Growing season
- 122 days
Safer after May 31 (1-in-10 risk)
Possible by Aug 29 (1-in-10 risk)
Last frost typically in 196 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 10 · May 25 · Jun 7 | Aug 16 · Sep 1 · Sep 15 | 99 days | 100% |
| Frost / freeze (32°F) | May 2 · May 13 · May 31 | Aug 29 · Sep 15 · Sep 28 | 122 days | 100% |
| Hard freeze (28°F) | Apr 23 · May 5 · May 22 | Sep 11 · Sep 25 · Oct 8 | 142 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 12 – Jun 18 |
| Tomatoes | Transplant outdoors | May 29 – May 26 |
| Peppers | Start seeds indoors | Apr 12 – May 13 |
| Peppers | Transplant outdoors | Jun 12 – Jul 13 |
| Eggplant | Start seeds indoors | Apr 29 – May 28 |
| Eggplant | Transplant outdoors | Jun 12 – Jul 13 |
| Cucumbers | Sow outdoors | Jun 12 – Jun 5 |
| Summer squash | Sow outdoors | May 29 – Jul 13 |
| Winter squash & pumpkins | Sow outdoors | Jun 12 – Jul 13 |
| Snap beans | Sow outdoors | May 29 – Jun 28 |
| Sweet corn | Sow outdoors | May 29 – May 26 |
| Watermelon & cantaloupe | Sow outdoors | Jun 12 – Jul 13 |
| Okra | Sow outdoors | Jun 5 – Jun 28 |
| Peas | Sow outdoors (spring) | Apr 12 – May 28 |
| Potatoes | Plant outdoors (spring) | Apr 12 – Jun 12 |
| Onions | Start seeds indoors (spring) | Mar 1 – Mar 28 |
| Onions | Transplant outdoors (spring) | Apr 29 – May 28 |
| Broccoli | Start seeds indoors (spring) | Mar 25 – Apr 28 |
| Broccoli | Transplant outdoors (spring) | Apr 29 – May 28 |
| Broccoli | Start seeds indoors (fall) | May 16 – May 26 |
| Broccoli | Transplant outdoors (fall) | Jun 15 – Jun 26 |
| Cabbage | Start seeds indoors (spring) | Mar 15 – Apr 12 |
| Cabbage | Transplant outdoors (spring) | Apr 12 – May 13 |
| Cabbage | Start seeds indoors (fall) | May 6 – Jun 5 |
| Cabbage | Transplant outdoors (fall) | Jun 5 – Jul 6 |
| Leaf lettuce | Sow outdoors (spring) | Apr 12 – Jun 28 |
| Leaf lettuce | Sow outdoors (fall) | Jun 5 – Jul 22 |
| Spinach | Sow outdoors (spring) | Apr 5 – May 19 |
| Spinach | Sow outdoors (fall) | Jun 22 – Jul 27 |
| Radishes | Sow outdoors (spring) | Apr 12 – Jun 2 |
| Radishes | Sow outdoors (fall) | Jun 5 – Aug 6 |
| Kale | Sow outdoors (spring) | Apr 29 – May 19 |
| Kale | Sow outdoors (fall) | May 29 – Jul 6 |
| Carrots | Sow outdoors (spring) | May 13 – Jun 28 |
| Carrots | Sow outdoors (fall) | May 6 – Jun 21 |
| Garlic | Plant outdoors (fall) | Sep 5 – Oct 6 |
Where these dates come from
ZIP code 99708 is matched to the NOAA station College 5 Nw, AK, 2.7 km away, at 978 ft elevation (498 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| College 5 Nw, AK (used) | 978 ft | May 13 | Sep 15 |
| Ester 5Ne, AK | 630 ft | — | — |
| Goldstream Creek, AK | 577 ft | — | — |
| College Obsy, AK | 597 ft | May 18 | Sep 6 |
Frost dates near Fairbanks
- Fairbanks, AK 99775 · last May 18, first Sep 6
- 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
- Two Rivers, AK 99716 · last May 30, first Sep 2
- Eielson Afb, AK 99702 · last May 20, first Sep 1
- 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 99708, the average last spring frost (32°F) is May 13, based on NOAA 1991-2020 climate normals for the College 5 Nw, AK weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Fairbanks, AK?
- The average first fall frost (32°F) is September 15. There is a 1-in-10 chance of frost by August 29, so tender plants are at risk from that point on.
- How long is the growing season in 99708?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 122 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.