Frost dates for 03854New Castle, NH
The average last spring frost in New Castle is May 4 and the average first fall frost is October 8, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 4
- Average first fall frost
- Oct 8
- Growing season
- 157 days
Safer after May 18 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 182 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 3 · May 16 · May 29 | Sep 16 · Sep 30 · Oct 10 | 134 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 4 · May 18 | Sep 27 · Oct 8 · Oct 24 | 157 days | 100% |
| Hard freeze (28°F) | Apr 7 · Apr 23 · May 7 | Oct 5 · Oct 21 · Nov 5 | 180 days | 100% |
Planting calendar for New Castle
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 3 – Jun 9 |
| Tomatoes | Transplant outdoors | May 20 – Jun 18 |
| Peppers | Start seeds indoors | Apr 3 – May 4 |
| Peppers | Transplant outdoors | Jun 3 – Jul 4 |
| Eggplant | Start seeds indoors | Apr 20 – May 19 |
| Eggplant | Transplant outdoors | Jun 3 – Jul 4 |
| Cucumbers | Sow outdoors | Jun 3 – Jun 28 |
| Summer squash | Sow outdoors | May 20 – Jul 4 |
| Winter squash & pumpkins | Sow outdoors | Jun 3 – Jul 4 |
| Snap beans | Sow outdoors | May 20 – Jul 21 |
| Sweet corn | Sow outdoors | May 20 – Jun 18 |
| Watermelon & cantaloupe | Sow outdoors | Jun 3 – Jul 4 |
| Okra | Sow outdoors | May 27 – Jun 19 |
| Peas | Sow outdoors (spring) | Apr 3 – May 19 |
| Potatoes | Plant outdoors (spring) | Apr 3 – Jun 3 |
| Onions | Start seeds indoors (spring) | Feb 20 – Mar 19 |
| Onions | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (spring) | Mar 16 – Apr 19 |
| Broccoli | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (fall) | Jun 8 – Jun 18 |
| Broccoli | Transplant outdoors (fall) | Jul 8 – Jul 19 |
| Cabbage | Start seeds indoors (spring) | Mar 6 – Apr 3 |
| Cabbage | Transplant outdoors (spring) | Apr 3 – May 4 |
| Cabbage | Start seeds indoors (fall) | May 29 – Jun 28 |
| Cabbage | Transplant outdoors (fall) | Jun 28 – Jul 29 |
| Leaf lettuce | Sow outdoors (spring) | Apr 3 – Jun 19 |
| Leaf lettuce | Sow outdoors (fall) | Jun 28 – Aug 14 |
| Spinach | Sow outdoors (spring) | Mar 27 – May 10 |
| Spinach | Sow outdoors (fall) | Jul 15 – Aug 19 |
| Radishes | Sow outdoors (spring) | Apr 3 – May 24 |
| Radishes | Sow outdoors (fall) | Jun 28 – Aug 29 |
| Kale | Sow outdoors (spring) | Apr 20 – May 10 |
| Kale | Sow outdoors (fall) | Jun 21 – Jul 29 |
| Carrots | Sow outdoors (spring) | May 4 – Jun 19 |
| Carrots | Sow outdoors (fall) | May 29 – Jul 14 |
| Garlic | Plant outdoors (fall) | Sep 28 – Oct 29 |
Where these dates come from
ZIP code 03854 is matched to the NOAA station Greenland, NH, 10.1 km away, at 95 ft elevation (79 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Greenland, NH (used) | 95 ft | May 4 | Oct 8 |
| Cape Neddick, ME | 152 ft | May 1 | Oct 14 |
| Durham 2 Ssw, NH | 63 ft | May 7 | Oct 4 |
| Durham 2 N, NH | 119 ft | May 3 | Oct 10 |
Frost dates near New Castle
- Kittery, ME 03904 · last May 4, first Oct 8
- Kittery Point, ME 03905 · last May 4, first Oct 8
- Portsmouth, NH 03802 · last May 4, first Oct 8
- Rye, NH 03870 · last May 4, first Oct 8
- Eliot, ME 03903 · last May 7, first Oct 4
- York Harbor, ME 03911 · last May 4, first Oct 8
- Rye Beach, NH 03871 · last May 4, first Oct 8
- York, ME 03909 · last May 4, first Oct 8
Frequently asked questions
- When is the last frost in New Castle, NH?
- For ZIP code 03854, the average last spring frost (32°F) is May 4, based on NOAA 1991-2020 climate normals for the Greenland, NH weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in New Castle, NH?
- The average first fall frost (32°F) is October 8. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 03854?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 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.