Frost dates for 04422Charleston, ME
The average last spring frost in Charleston is May 15 and the average first fall frost is September 28, giving a typical growing season of about 134 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Sep 28
- Growing season
- 134 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 15 (1-in-10 risk)
Last frost typically in 195 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 15 · May 28 · Jun 8 | Sep 6 · Sep 18 · Oct 1 | 113 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 15 · May 28 | Sep 15 · Sep 28 · Oct 9 | 134 days | 100% |
| Hard freeze (28°F) | Apr 22 · May 2 · May 16 | Sep 26 · Oct 9 · Oct 25 | 157 days | 100% |
Planting calendar for Charleston
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 14 – Jun 20 |
| Tomatoes | Transplant outdoors | May 31 – Jun 8 |
| Peppers | Start seeds indoors | Apr 14 – May 15 |
| Peppers | Transplant outdoors | Jun 14 – Jul 15 |
| Eggplant | Start seeds indoors | May 1 – May 30 |
| Eggplant | Transplant outdoors | Jun 14 – Jul 15 |
| Cucumbers | Sow outdoors | Jun 14 – Jun 18 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 11 |
| Sweet corn | Sow outdoors | May 31 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 14 – Jul 15 |
| Okra | Sow outdoors | Jun 7 – Jun 30 |
| Peas | Sow outdoors (spring) | Apr 14 – May 30 |
| Potatoes | Plant outdoors (spring) | Apr 14 – Jun 14 |
| Onions | Start seeds indoors (spring) | Mar 3 – Mar 30 |
| Onions | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (spring) | Mar 27 – Apr 30 |
| Broccoli | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 04422 is matched to the NOAA station Dover-Foxcroft Wwtp, ME, 15.4 km away, at 370 ft elevation (63 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Dover-Foxcroft Wwtp, ME (used) | 370 ft | May 15 | Sep 28 |
| E Sangerville, ME | 635 ft | May 6 | Oct 7 |
| Corinna, ME | 297 ft | May 8 | Oct 3 |
| Sebec Lake, ME | 380 ft | May 16 | Oct 1 |
Frost dates near Charleston
- Garland, ME 04939 · last May 8, first Oct 3
- Exeter, ME 04435 · last May 8, first Oct 3
- Corinth, ME 04427 · last May 8, first Oct 3
- Bradford, ME 04410 · last May 15, first Sep 28
- Dexter, ME 04930 · last May 8, first Oct 3
- Dover Foxcroft, ME 04426 · last May 15, first Sep 28
- Hudson, ME 04449 · last May 13, first Sep 28
- Corinna, ME 04928 · last May 8, first Oct 3
Frequently asked questions
- When is the last frost in Charleston, ME?
- For ZIP code 04422, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Dover-Foxcroft Wwtp, ME weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Charleston, ME?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 15, so tender plants are at risk from that point on.
- How long is the growing season in 04422?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 134 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.