Frost dates for 03280Washington, NH
The average last spring frost in Washington is May 2 and the average first fall frost is October 9, giving a typical growing season of about 158 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 2
- Average first fall frost
- Oct 9
- Growing season
- 158 days
Safer after May 17 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 181 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 2 · May 14 · May 29 | Sep 16 · Sep 30 · Oct 12 | 137 days | 100% |
| Frost / freeze (32°F) | Apr 21 · May 2 · May 17 | Sep 27 · Oct 9 · Oct 24 | 158 days | 100% |
| Hard freeze (28°F) | Apr 9 · Apr 21 · May 3 | Oct 4 · Oct 21 · Nov 5 | 181 days | 100% |
Planting calendar for 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 1 – Jun 7 |
| Tomatoes | Transplant outdoors | May 18 – Jun 19 |
| Peppers | Start seeds indoors | Apr 1 – May 2 |
| Peppers | Transplant outdoors | Jun 1 – Jul 2 |
| Eggplant | Start seeds indoors | Apr 18 – May 17 |
| Eggplant | Transplant outdoors | Jun 1 – Jul 2 |
| Cucumbers | Sow outdoors | Jun 1 – Jun 29 |
| Summer squash | Sow outdoors | May 18 – Jul 2 |
| Winter squash & pumpkins | Sow outdoors | Jun 1 – Jul 2 |
| Snap beans | Sow outdoors | May 18 – Jul 22 |
| Sweet corn | Sow outdoors | May 18 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 1 – Jul 2 |
| Okra | Sow outdoors | May 25 – Jun 17 |
| Peas | Sow outdoors (spring) | Apr 1 – May 17 |
| Potatoes | Plant outdoors (spring) | Apr 1 – Jun 1 |
| Onions | Start seeds indoors (spring) | Feb 18 – Mar 17 |
| Onions | Transplant outdoors (spring) | Apr 18 – May 17 |
| Broccoli | Start seeds indoors (spring) | Mar 14 – Apr 17 |
| Broccoli | Transplant outdoors (spring) | Apr 18 – May 17 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 4 – Apr 1 |
| Cabbage | Transplant outdoors (spring) | Apr 1 – May 2 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 1 – Jun 17 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 25 – May 8 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 1 – May 22 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 18 – May 8 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 2 – Jun 17 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 03280 is matched to the NOAA station Mt Sunapee, NH, 17.5 km away, at 1,275 ft elevation (228 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mt Sunapee, NH (used) | 1,275 ft | May 2 | Oct 9 |
| Bradford 2, NH | 815 ft | May 15 | Sep 27 |
| Newport, NH | 770 ft | May 14 | Oct 1 |
| Hopkinton Lake, NH | 430 ft | May 6 | Oct 1 |
Frost dates near Washington
- Lempster, NH 03605 · last May 2, first Oct 9
- Stoddard, NH 03464 · last May 2, first Oct 9
- Marlow, NH 03456 · last May 2, first Oct 9
- Bradford, NH 03221 · last May 15, first Sep 27
- Goshen, NH 03752 · last May 2, first Oct 9
- South Newbury, NH 03272 · last May 14, first Oct 1
- South Acworth, NH 03607 · last May 2, first Oct 9
- Hillsborough, NH 03244 · last May 2, first Oct 8
Frequently asked questions
- When is the last frost in Washington, NH?
- For ZIP code 03280, the average last spring frost (32°F) is May 2, based on NOAA 1991-2020 climate normals for the Mt Sunapee, NH weather station. There is a 1-in-10 chance of a frost after May 17.
- When is the first frost in Washington, NH?
- The average first fall frost (32°F) is October 9. 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 03280?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 158 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.