Frost dates for 99777Tanana, AK
The average last spring frost in Tanana is May 29 and the average first fall frost is August 28, giving a typical growing season of about 89 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 29
- Average first fall frost
- Aug 28
- Growing season
- 89 days
Safer after Jun 16 (1-in-10 risk)
Possible by Aug 10 (1-in-10 risk)
Last frost typically in 209 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) | — | — | 59 days | 100% |
| Frost / freeze (32°F) | May 15 · May 29 · Jun 16 | Aug 10 · Aug 28 · Sep 9 | 89 days | 100% |
| Hard freeze (28°F) | May 5 · May 16 · May 30 | Aug 25 · Sep 8 · Sep 25 | 114 days | 100% |
Planting calendar for Tanana
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 28 – Jul 4 |
| Tomatoes | Transplant outdoors | Jun 14 – May 8 |
| Peppers | Start seeds indoors | Apr 28 – May 29 |
| Peppers | Transplant outdoors | Jun 28 – Jul 29 |
| Eggplant | Start seeds indoors | May 15 – Jun 13 |
| Eggplant | Transplant outdoors | Jun 28 – Jul 29 |
| Cucumbers | Sow outdoors | Jun 28 – May 18 |
| Summer squash | Sow outdoors | Jun 14 – Jul 29 |
| Winter squash & pumpkins | Sow outdoors | Jun 28 – Jul 29 |
| Snap beans | Sow outdoors | Jun 14 – Jun 10 |
| Sweet corn | Sow outdoors | Jun 14 – May 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 28 – Jul 29 |
| Okra | Sow outdoors | Jun 21 – Jul 14 |
| Peas | Sow outdoors (spring) | Apr 28 – Jun 13 |
| Potatoes | Plant outdoors (spring) | Apr 28 – Jun 28 |
| Onions | Start seeds indoors (spring) | Mar 17 – Apr 13 |
| Onions | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (spring) | Apr 10 – May 14 |
| Broccoli | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (fall) | Apr 28 – May 8 |
| Broccoli | Transplant outdoors (fall) | May 28 – Jun 8 |
| Cabbage | Start seeds indoors (spring) | Mar 31 – Apr 28 |
| Cabbage | Transplant outdoors (spring) | Apr 28 – May 29 |
| Cabbage | Start seeds indoors (fall) | Apr 18 – May 18 |
| Cabbage | Transplant outdoors (fall) | May 18 – Jun 18 |
| Leaf lettuce | Sow outdoors (spring) | Apr 28 – Jul 14 |
| Leaf lettuce | Sow outdoors (fall) | May 18 – Jul 4 |
| Spinach | Sow outdoors (spring) | Apr 21 – Jun 4 |
| Spinach | Sow outdoors (fall) | Jun 4 – Jul 9 |
| Radishes | Sow outdoors (spring) | Apr 28 – Jun 18 |
| Radishes | Sow outdoors (fall) | May 18 – Jul 19 |
| Kale | Sow outdoors (spring) | May 15 – Jun 4 |
| Kale | Sow outdoors (fall) | May 11 – Jun 18 |
| Carrots | Sow outdoors (spring) | May 29 – Jul 14 |
| Carrots | Sow outdoors (fall) | Apr 18 – Jun 3 |
| Garlic | Plant outdoors (fall) | Aug 18 – Sep 18 |
Where these dates come from
ZIP code 99777 is matched to the NOAA station Tanana Calhoun Mem Ap, AK, 1.3 km away, at 227 ft elevation (3 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Tanana Calhoun Mem Ap, AK (used) | 227 ft | May 29 | Aug 28 |
| Manley Hot Springs 15Ne, AK | 501 ft | — | — |
| Ruby 44 Ese, AK | 259 ft | May 22 | Sep 3 |
| Minchumina, AK | 1,025 ft | May 13 | Sep 17 |
Frost dates near Tanana
- Bettles Field, AK 99726 · last —, first —
Frequently asked questions
- When is the last frost in Tanana, AK?
- For ZIP code 99777, the average last spring frost (32°F) is May 29, based on NOAA 1991-2020 climate normals for the Tanana Calhoun Mem Ap, AK weather station. There is a 1-in-10 chance of a frost after June 16.
- When is the first frost in Tanana, AK?
- The average first fall frost (32°F) is August 28. There is a 1-in-10 chance of frost by August 10, so tender plants are at risk from that point on.
- How long is the growing season in 99777?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 89 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.