Frost dates for 03589Mount Washington, NH
The average last spring frost in Mount Washington is May 23 and the average first fall frost is September 22, giving a typical growing season of about 122 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 23
- Average first fall frost
- Sep 22
- Growing season
- 122 days
Safer after Jun 6 (1-in-10 risk)
Possible by Sep 9 (1-in-10 risk)
Last frost typically in 203 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 21 · Jun 4 · Jun 20 | Aug 29 · Sep 11 · Sep 24 | 97 days | 100% |
| Frost / freeze (32°F) | May 8 · May 23 · Jun 6 | Sep 9 · Sep 22 · Oct 3 | 122 days | 100% |
| Hard freeze (28°F) | Apr 27 · May 8 · May 23 | Sep 19 · Oct 2 · Oct 19 | 146 days | 100% |
Planting calendar for Mount Washington
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 22 – Jun 28 |
| Tomatoes | Transplant outdoors | Jun 8 – Jun 2 |
| Peppers | Start seeds indoors | Apr 22 – May 23 |
| Peppers | Transplant outdoors | Jun 22 – Jul 23 |
| Eggplant | Start seeds indoors | May 9 – Jun 7 |
| Eggplant | Transplant outdoors | Jun 22 – Jul 23 |
| Cucumbers | Sow outdoors | Jun 22 – Jun 12 |
| Summer squash | Sow outdoors | Jun 8 – Jul 23 |
| Winter squash & pumpkins | Sow outdoors | Jun 22 – Jul 23 |
| Snap beans | Sow outdoors | Jun 8 – Jul 5 |
| Sweet corn | Sow outdoors | Jun 8 – Jun 2 |
| Watermelon & cantaloupe | Sow outdoors | Jun 22 – Jul 23 |
| Okra | Sow outdoors | Jun 15 – Jul 8 |
| Peas | Sow outdoors (spring) | Apr 22 – Jun 7 |
| Potatoes | Plant outdoors (spring) | Apr 22 – Jun 22 |
| Onions | Start seeds indoors (spring) | Mar 11 – Apr 7 |
| Onions | Transplant outdoors (spring) | May 9 – Jun 7 |
| Broccoli | Start seeds indoors (spring) | Apr 4 – May 8 |
| Broccoli | Transplant outdoors (spring) | May 9 – Jun 7 |
| Broccoli | Start seeds indoors (fall) | May 23 – Jun 2 |
| Broccoli | Transplant outdoors (fall) | Jun 22 – Jul 3 |
| Cabbage | Start seeds indoors (spring) | Mar 25 – Apr 22 |
| Cabbage | Transplant outdoors (spring) | Apr 22 – May 23 |
| Cabbage | Start seeds indoors (fall) | May 13 – Jun 12 |
| Cabbage | Transplant outdoors (fall) | Jun 12 – Jul 13 |
| Leaf lettuce | Sow outdoors (spring) | Apr 22 – Jul 8 |
| Leaf lettuce | Sow outdoors (fall) | Jun 12 – Jul 29 |
| Spinach | Sow outdoors (spring) | Apr 15 – May 29 |
| Spinach | Sow outdoors (fall) | Jun 29 – Aug 3 |
| Radishes | Sow outdoors (spring) | Apr 22 – Jun 12 |
| Radishes | Sow outdoors (fall) | Jun 12 – Aug 13 |
| Kale | Sow outdoors (spring) | May 9 – May 29 |
| Kale | Sow outdoors (fall) | Jun 5 – Jul 13 |
| Carrots | Sow outdoors (spring) | May 23 – Jul 8 |
| Carrots | Sow outdoors (fall) | May 13 – Jun 28 |
| Garlic | Plant outdoors (fall) | Sep 12 – Oct 13 |
Where these dates come from
ZIP code 03589 is matched to the NOAA station York Pond, NH, 21.4 km away, at 1,519 ft elevation (1,181 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| York Pond, NH (used) | 1,519 ft | May 23 | Sep 22 |
| N Stratford, NH | 950 ft | May 19 | Sep 29 |
| Errol Ap, NH | 1,240 ft | May 21 | Sep 22 |
| Berlin Muni Ap, NH | 1,158 ft | May 30 | Sep 19 |
Frost dates near Mount Washington
- West Stewartstown, NH 03597 · last May 23, first Sep 22
- North Stratford, NH 03590 · last May 23, first Sep 22
- Groveton, NH 03582 · last May 18, first Sep 30
- Guildhall, VT 05905 · last May 19, first Sep 29
- Milan, NH 03588 · last May 30, first Sep 19
- Errol, NH 03579 · last May 19, first Oct 1
- Colebrook, NH 03576 · last May 31, first Sep 21
- Granby, VT 05840 · last May 19, first Sep 29
Frequently asked questions
- When is the last frost in Mount Washington, NH?
- For ZIP code 03589, the average last spring frost (32°F) is May 23, based on NOAA 1991-2020 climate normals for the York Pond, NH weather station. There is a 1-in-10 chance of a frost after June 6.
- When is the first frost in Mount Washington, NH?
- The average first fall frost (32°F) is September 22. There is a 1-in-10 chance of frost by September 9, so tender plants are at risk from that point on.
- How long is the growing season in 03589?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 122 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.