Frost dates for 03872Sanbornville, NH
The average last spring frost in Sanbornville is May 16 and the average first fall frost is September 30, giving a typical growing season of about 136 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 30
- Growing season
- 136 days
Safer after May 29 (1-in-10 risk)
Possible by Sep 18 (1-in-10 risk)
Last frost typically in 194 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 26 · Jun 6 | Sep 6 · Sep 20 · Oct 1 | 114 days | 100% |
| Frost / freeze (32°F) | May 2 · May 16 · May 29 | Sep 18 · Sep 30 · Oct 10 | 136 days | 100% |
| Hard freeze (28°F) | Apr 21 · May 2 · May 17 | Sep 28 · Oct 7 · Oct 24 | 157 days | 100% |
Planting calendar for Sanbornville
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – Jun 10 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 20 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 13 |
| Sweet corn | Sow outdoors | Jun 1 – Jun 10 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 31 – Jun 10 |
| Broccoli | Transplant outdoors (fall) | Jun 30 – Jul 11 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 21 – Jun 20 |
| Cabbage | Transplant outdoors (fall) | Jun 20 – Jul 21 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 20 – Aug 6 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jul 7 – Aug 11 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 20 – Aug 21 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 13 – Jul 21 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 21 – Jul 6 |
| Garlic | Plant outdoors (fall) | Sep 20 – Oct 21 |
Where these dates come from
ZIP code 03872 is matched to the NOAA station Sanford 2 Nnw, ME, 22 km away, at 289 ft elevation (279 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sanford 2 Nnw, ME (used) | 289 ft | May 16 | Sep 30 |
| Hollis, ME | 304 ft | May 14 | Sep 30 |
| Rochester Skyhaven Ap, NH | 323 ft | Apr 30 | Oct 9 |
| Lakeport 2, NH | 500 ft | Apr 30 | Oct 18 |
Frost dates near Sanbornville
- Milton Mills, NH 03852 · last May 16, first Sep 30
- East Wakefield, NH 03830 · last May 16, first Sep 26
- Acton, ME 04001 · last May 16, first Sep 30
- Union, NH 03887 · last May 16, first Sep 30
- West Newfield, ME 04095 · last May 14, first Sep 30
- Lebanon, ME 04027 · last May 16, first Sep 30
- Milton, NH 03851 · last Apr 30, first Oct 9
- Wolfeboro, NH 03894 · last Apr 30, first Oct 18
Frequently asked questions
- When is the last frost in Sanbornville, NH?
- For ZIP code 03872, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Sanford 2 Nnw, ME weather station. There is a 1-in-10 chance of a frost after May 29.
- When is the first frost in Sanbornville, NH?
- The average first fall frost (32°F) is September 30. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 03872?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 136 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.