Frost dates for 99660Saint Paul Island, AK
The average last spring frost in Saint Paul Island is June 4 and the average first fall frost is September 28, giving a typical growing season of about 114 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 4
- Average first fall frost
- Sep 28
- Growing season
- 114 days
Safer after Jun 25 (1-in-10 risk)
Possible by Sep 11 (1-in-10 risk)
Last frost typically in 220 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) | — | — | 74 days | 100% |
| Frost / freeze (32°F) | May 16 · Jun 4 · Jun 25 | Sep 11 · Sep 28 · Oct 15 | 114 days | 100% |
| Hard freeze (28°F) | May 1 · May 17 · Jun 6 | Sep 26 · Oct 15 · Nov 4 | 149 days | 100% |
Planting calendar for Saint Paul Island
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 | May 4 – Jul 10 |
| Tomatoes | Transplant outdoors | Jun 20 – Jun 8 |
| Peppers | Start seeds indoors | May 4 – Jun 4 |
| Peppers | Transplant outdoors | Jul 4 – Aug 4 |
| Eggplant | Start seeds indoors | May 21 – Jun 19 |
| Eggplant | Transplant outdoors | Jul 4 – Aug 4 |
| Cucumbers | Sow outdoors | Jul 4 – Jun 18 |
| Summer squash | Sow outdoors | Jun 20 – Aug 4 |
| Winter squash & pumpkins | Sow outdoors | Jul 4 – Aug 4 |
| Snap beans | Sow outdoors | Jun 20 – Jul 11 |
| Sweet corn | Sow outdoors | Jun 20 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jul 4 – Aug 4 |
| Okra | Sow outdoors | Jun 27 – Jul 20 |
| Peas | Sow outdoors (spring) | May 4 – Jun 19 |
| Potatoes | Plant outdoors (spring) | May 4 – Jul 4 |
| Onions | Start seeds indoors (spring) | Mar 23 – Apr 19 |
| Onions | Transplant outdoors (spring) | May 21 – Jun 19 |
| Broccoli | Start seeds indoors (spring) | Apr 16 – May 20 |
| Broccoli | Transplant outdoors (spring) | May 21 – Jun 19 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Apr 6 – May 4 |
| Cabbage | Transplant outdoors (spring) | May 4 – Jun 4 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | May 4 – Jul 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 27 – Jun 10 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | May 4 – Jun 24 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | May 21 – Jun 10 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | Jun 4 – Jul 20 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 99660 is matched to the NOAA station St Paul Island Ap, AK, 4.6 km away, at 35 ft elevation (136 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| St Paul Island Ap, AK (used) | 35 ft | Jun 4 | Sep 28 |
| St. Paul 4 Ne, AK | 20 ft | Jun 5 | Sep 28 |
| St George Island Ap, AK | 125 ft | May 31 | Oct 5 |
| Dutch Harbor, AK | 10 ft | May 6 | Oct 18 |
Frost dates near Saint Paul Island
- Saint George Island, AK 99591 · last May 31, first Oct 5
Frequently asked questions
- When is the last frost in Saint Paul Island, AK?
- For ZIP code 99660, the average last spring frost (32°F) is June 4, based on NOAA 1991-2020 climate normals for the St Paul Island Ap, AK weather station. There is a 1-in-10 chance of a frost after June 25.
- When is the first frost in Saint Paul Island, AK?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 11, so tender plants are at risk from that point on.
- How long is the growing season in 99660?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 114 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.