Frost dates for 03576Colebrook, NH
The average last spring frost in Colebrook is May 31 and the average first fall frost is September 21, giving a typical growing season of about 112 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 31
- Average first fall frost
- Sep 21
- Growing season
- 112 days
Safer after Jun 14 (1-in-10 risk)
Possible by Sep 7 (1-in-10 risk)
Last frost typically in 211 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 29 · Jun 10 · Jul 1 | Aug 19 · Sep 7 · Sep 21 | 86 days | 100% |
| Frost / freeze (32°F) | May 16 · May 31 · Jun 14 | Sep 7 · Sep 21 · Oct 2 | 112 days | 100% |
| Hard freeze (28°F) | May 2 · May 17 · May 31 | Sep 20 · Oct 1 · Oct 13 | 135 days | 100% |
Planting calendar for Colebrook
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 30 – Jul 6 |
| Tomatoes | Transplant outdoors | Jun 16 – Jun 1 |
| Peppers | Start seeds indoors | Apr 30 – May 31 |
| Peppers | Transplant outdoors | Jun 30 – Jul 31 |
| Eggplant | Start seeds indoors | May 17 – Jun 15 |
| Eggplant | Transplant outdoors | Jun 30 – Jul 31 |
| Cucumbers | Sow outdoors | Jun 30 – Jun 11 |
| Summer squash | Sow outdoors | Jun 16 – Jul 31 |
| Winter squash & pumpkins | Sow outdoors | Jun 30 – Jul 31 |
| Snap beans | Sow outdoors | Jun 16 – Jul 4 |
| Sweet corn | Sow outdoors | Jun 16 – Jun 1 |
| Watermelon & cantaloupe | Sow outdoors | Jun 30 – Jul 31 |
| Okra | Sow outdoors | Jun 23 – Jul 16 |
| Peas | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Potatoes | Plant outdoors (spring) | Apr 30 – Jun 30 |
| Onions | Start seeds indoors (spring) | Mar 19 – Apr 15 |
| Onions | Transplant outdoors (spring) | May 17 – Jun 15 |
| Broccoli | Start seeds indoors (spring) | Apr 12 – May 16 |
| Broccoli | Transplant outdoors (spring) | May 17 – Jun 15 |
| Broccoli | Start seeds indoors (fall) | May 22 – Jun 1 |
| Broccoli | Transplant outdoors (fall) | Jun 21 – Jul 2 |
| Cabbage | Start seeds indoors (spring) | Apr 2 – Apr 30 |
| Cabbage | Transplant outdoors (spring) | Apr 30 – May 31 |
| Cabbage | Start seeds indoors (fall) | May 12 – Jun 11 |
| Cabbage | Transplant outdoors (fall) | Jun 11 – Jul 12 |
| Leaf lettuce | Sow outdoors (spring) | Apr 30 – Jul 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 11 – Jul 28 |
| Spinach | Sow outdoors (spring) | Apr 23 – Jun 6 |
| Spinach | Sow outdoors (fall) | Jun 28 – Aug 2 |
| Radishes | Sow outdoors (spring) | Apr 30 – Jun 20 |
| Radishes | Sow outdoors (fall) | Jun 11 – Aug 12 |
| Kale | Sow outdoors (spring) | May 17 – Jun 6 |
| Kale | Sow outdoors (fall) | Jun 4 – Jul 12 |
| Carrots | Sow outdoors (spring) | May 31 – Jul 16 |
| Carrots | Sow outdoors (fall) | May 12 – Jun 27 |
| Garlic | Plant outdoors (fall) | Sep 11 – Oct 12 |
Where these dates come from
ZIP code 03576 is matched to the NOAA station Colebrook 3Sw, NH, 7 km away, at 1,120 ft elevation (77 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Colebrook 3Sw, NH (used) | 1,120 ft | May 31 | Sep 21 |
| Averill, VT | 1,699 ft | May 25 | Sep 22 |
| First Connecticut Lake, NH | 1,650 ft | May 25 | Sep 24 |
| N Stratford, NH | 950 ft | May 19 | Sep 29 |
Frost dates near Colebrook
- Canaan, VT 05903 · last May 31, first Sep 21
- Beecher Falls, VT 05902 · last May 31, first Sep 21
- Averill, VT 05901 · last May 25, first Sep 22
- Pittsburg, NH 03592 · last May 25, first Sep 24
- North Stratford, NH 03590 · last May 23, first Sep 22
- Mount Washington, NH 03589 · last May 23, first Sep 22
- West Stewartstown, NH 03597 · last May 23, first Sep 22
- Norton, VT 05907 · last May 25, first Sep 22
Frequently asked questions
- When is the last frost in Colebrook, NH?
- For ZIP code 03576, the average last spring frost (32°F) is May 31, based on NOAA 1991-2020 climate normals for the Colebrook 3Sw, NH weather station. There is a 1-in-10 chance of a frost after June 14.
- When is the first frost in Colebrook, NH?
- The average first fall frost (32°F) is September 21. There is a 1-in-10 chance of frost by September 7, so tender plants are at risk from that point on.
- How long is the growing season in 03576?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 112 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.