Frost dates for 99687Wasilla, AK
The average last spring frost in Wasilla is May 14 and the average first fall frost is September 20, giving a typical growing season of about 127 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 14
- Average first fall frost
- Sep 20
- Growing season
- 127 days
Safer after May 26 (1-in-10 risk)
Possible by Sep 6 (1-in-10 risk)
Last frost typically in 198 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 28 · Jun 6 | Aug 27 · Sep 8 · Sep 20 | 102 days | 100% |
| Frost / freeze (32°F) | May 3 · May 14 · May 26 | Sep 6 · Sep 20 · Oct 1 | 127 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 1 · May 13 | Sep 18 · Oct 1 · Oct 15 | 152 days | 100% |
Planting calendar for Wasilla
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 13 – Jun 19 |
| Tomatoes | Transplant outdoors | May 30 – May 31 |
| Peppers | Start seeds indoors | Apr 13 – May 14 |
| Peppers | Transplant outdoors | Jun 13 – Jul 14 |
| Eggplant | Start seeds indoors | Apr 30 – May 29 |
| Eggplant | Transplant outdoors | Jun 13 – Jul 14 |
| Cucumbers | Sow outdoors | Jun 13 – Jun 10 |
| Summer squash | Sow outdoors | May 30 – Jul 14 |
| Winter squash & pumpkins | Sow outdoors | Jun 13 – Jul 14 |
| Snap beans | Sow outdoors | May 30 – Jul 3 |
| Sweet corn | Sow outdoors | May 30 – May 31 |
| Watermelon & cantaloupe | Sow outdoors | Jun 13 – Jul 14 |
| Okra | Sow outdoors | Jun 6 – Jun 29 |
| Peas | Sow outdoors (spring) | Apr 13 – May 29 |
| Potatoes | Plant outdoors (spring) | Apr 13 – Jun 13 |
| Onions | Start seeds indoors (spring) | Mar 2 – Mar 29 |
| Onions | Transplant outdoors (spring) | Apr 30 – May 29 |
| Broccoli | Start seeds indoors (spring) | Mar 26 – Apr 29 |
| Broccoli | Transplant outdoors (spring) | Apr 30 – May 29 |
| Broccoli | Start seeds indoors (fall) | May 21 – May 31 |
| Broccoli | Transplant outdoors (fall) | Jun 20 – Jul 1 |
| Cabbage | Start seeds indoors (spring) | Mar 16 – Apr 13 |
| Cabbage | Transplant outdoors (spring) | Apr 13 – May 14 |
| Cabbage | Start seeds indoors (fall) | May 11 – Jun 10 |
| Cabbage | Transplant outdoors (fall) | Jun 10 – Jul 11 |
| Leaf lettuce | Sow outdoors (spring) | Apr 13 – Jun 29 |
| Leaf lettuce | Sow outdoors (fall) | Jun 10 – Jul 27 |
| Spinach | Sow outdoors (spring) | Apr 6 – May 20 |
| Spinach | Sow outdoors (fall) | Jun 27 – Aug 1 |
| Radishes | Sow outdoors (spring) | Apr 13 – Jun 3 |
| Radishes | Sow outdoors (fall) | Jun 10 – Aug 11 |
| Kale | Sow outdoors (spring) | Apr 30 – May 20 |
| Kale | Sow outdoors (fall) | Jun 3 – Jul 11 |
| Carrots | Sow outdoors (spring) | May 14 – Jun 29 |
| Carrots | Sow outdoors (fall) | May 11 – Jun 26 |
| Garlic | Plant outdoors (fall) | Sep 10 – Oct 11 |
Where these dates come from
ZIP code 99687 is matched to the NOAA station Matanuska Exp Farm, AK, 12.5 km away, at 172 ft elevation (67 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Matanuska Exp Farm, AK (used) | 172 ft | May 14 | Sep 20 |
| Eklutna Wtp, AK | 640 ft | May 18 | Sep 20 |
| Anderson Lake, AK | 458 ft | May 16 | Sep 23 |
| Ben'S Farm, AK | 127 ft | May 12 | Sep 20 |
Frost dates near Wasilla
- Wasilla, AK 99623 · last May 16, first Sep 23
- Chugiak, AK 99567 · last May 21, first Sep 15
- Houston, AK 99694 · last May 29, first Sep 7
- Eagle River, AK 99577 · last May 9, first Sep 26
- Big Lake, AK 99652 · last May 29, first Sep 7
- Palmer, AK 99645 · last May 22, first Sep 16
- Anchorage, AK 99504 · last May 1, first Sep 29
- Sutton, AK 99674 · last Jun 1, first Sep 6
Frequently asked questions
- When is the last frost in Wasilla, AK?
- For ZIP code 99687, the average last spring frost (32°F) is May 14, based on NOAA 1991-2020 climate normals for the Matanuska Exp Farm, AK weather station. There is a 1-in-10 chance of a frost after May 26.
- When is the first frost in Wasilla, AK?
- The average first fall frost (32°F) is September 20. There is a 1-in-10 chance of frost by September 6, so tender plants are at risk from that point on.
- How long is the growing season in 99687?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 127 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.