Frost dates for 99826Gustavus, AK
The average last spring frost in Gustavus is May 30 and the average first fall frost is September 16, giving a typical growing season of about 107 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 30
- Average first fall frost
- Sep 16
- Growing season
- 107 days
Safer after Jun 22 (1-in-10 risk)
Possible by Aug 29 (1-in-10 risk)
Last frost typically in 215 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) | — | — | 70 days | 100% |
| Frost / freeze (32°F) | May 14 · May 30 · Jun 22 | Aug 29 · Sep 16 · Oct 4 | 107 days | 100% |
| Hard freeze (28°F) | Apr 27 · May 12 · May 27 | Sep 13 · Oct 1 · Oct 18 | 142 days | 100% |
Planting calendar for Gustavus
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 29 – Jul 5 |
| Tomatoes | Transplant outdoors | Jun 15 – May 27 |
| Peppers | Start seeds indoors | Apr 29 – May 30 |
| Peppers | Transplant outdoors | Jun 29 – Jul 30 |
| Eggplant | Start seeds indoors | May 16 – Jun 14 |
| Eggplant | Transplant outdoors | Jun 29 – Jul 30 |
| Cucumbers | Sow outdoors | Jun 29 – Jun 6 |
| Summer squash | Sow outdoors | Jun 15 – Jul 30 |
| Winter squash & pumpkins | Sow outdoors | Jun 29 – Jul 30 |
| Snap beans | Sow outdoors | Jun 15 – Jun 29 |
| Sweet corn | Sow outdoors | Jun 15 – May 27 |
| Watermelon & cantaloupe | Sow outdoors | Jun 29 – Jul 30 |
| Okra | Sow outdoors | Jun 22 – Jul 15 |
| Peas | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Potatoes | Plant outdoors (spring) | Apr 29 – Jun 29 |
| Onions | Start seeds indoors (spring) | Mar 18 – Apr 14 |
| Onions | Transplant outdoors (spring) | May 16 – Jun 14 |
| Broccoli | Start seeds indoors (spring) | Apr 11 – May 15 |
| Broccoli | Transplant outdoors (spring) | May 16 – Jun 14 |
| Broccoli | Start seeds indoors (fall) | May 17 – May 27 |
| Broccoli | Transplant outdoors (fall) | Jun 16 – Jun 27 |
| Cabbage | Start seeds indoors (spring) | Apr 1 – Apr 29 |
| Cabbage | Transplant outdoors (spring) | Apr 29 – May 30 |
| Cabbage | Start seeds indoors (fall) | May 7 – Jun 6 |
| Cabbage | Transplant outdoors (fall) | Jun 6 – Jul 7 |
| Leaf lettuce | Sow outdoors (spring) | Apr 29 – Jul 15 |
| Leaf lettuce | Sow outdoors (fall) | Jun 6 – Jul 23 |
| Spinach | Sow outdoors (spring) | Apr 22 – Jun 5 |
| Spinach | Sow outdoors (fall) | Jun 23 – Jul 28 |
| Radishes | Sow outdoors (spring) | Apr 29 – Jun 19 |
| Radishes | Sow outdoors (fall) | Jun 6 – Aug 7 |
| Kale | Sow outdoors (spring) | May 16 – Jun 5 |
| Kale | Sow outdoors (fall) | May 30 – Jul 7 |
| Carrots | Sow outdoors (spring) | May 30 – Jul 15 |
| Carrots | Sow outdoors (fall) | May 7 – Jun 22 |
| Garlic | Plant outdoors (fall) | Sep 6 – Oct 7 |
Where these dates come from
ZIP code 99826 is matched to the NOAA station Gustavus, AK, 3.6 km away, at 40 ft elevation (14 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Gustavus, AK (used) | 40 ft | May 30 | Sep 16 |
| Gustavus 2 Ne, AK | 20 ft | May 28 | Sep 25 |
| Glacier Bay, AK | 45 ft | May 6 | Oct 10 |
| Hoonah, AK | 130 ft | May 9 | Oct 4 |
Frost dates near Gustavus
- Hoonah, AK 99829 · last May 9, first Oct 4
- Elfin Cove, AK 99825 · last Apr 26, first Nov 1
- Pelican, AK 99832 · last May 4, first Oct 19
- Auke Bay, AK 99821 · last May 21, first Oct 1
- Juneau, AK 99801 · last May 4, first Oct 3
- Tenakee Springs, AK 99841 · last May 9, first Oct 4
- Haines, AK 99827 · last Apr 25, first Oct 12
- Angoon, AK 99820 · last Apr 29, first Oct 25
Frequently asked questions
- When is the last frost in Gustavus, AK?
- For ZIP code 99826, the average last spring frost (32°F) is May 30, based on NOAA 1991-2020 climate normals for the Gustavus, AK weather station. There is a 1-in-10 chance of a frost after June 22.
- When is the first frost in Gustavus, AK?
- The average first fall frost (32°F) is September 16. 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 99826?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 107 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.