Frost dates for 03583Jefferson, NH
The average last spring frost in Jefferson is May 27 and the average first fall frost is September 19, giving a typical growing season of about 116 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 27
- Average first fall frost
- Sep 19
- Growing season
- 116 days
Safer after Jun 10 (1-in-10 risk)
Possible by Sep 8 (1-in-10 risk)
Last frost typically in 207 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 26 · Jun 8 · Jun 28 | Aug 25 · Sep 8 · Sep 21 | 90 days | 100% |
| Frost / freeze (32°F) | May 11 · May 27 · Jun 10 | Sep 8 · Sep 19 · Oct 3 | 116 days | 100% |
| Hard freeze (28°F) | Apr 27 · May 11 · May 27 | Sep 18 · Oct 2 · Oct 17 | 142 days | 100% |
Planting calendar for Jefferson
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 26 – Jul 2 |
| Tomatoes | Transplant outdoors | Jun 12 – May 30 |
| Peppers | Start seeds indoors | Apr 26 – May 27 |
| Peppers | Transplant outdoors | Jun 26 – Jul 27 |
| Eggplant | Start seeds indoors | May 13 – Jun 11 |
| Eggplant | Transplant outdoors | Jun 26 – Jul 27 |
| Cucumbers | Sow outdoors | Jun 26 – Jun 9 |
| Summer squash | Sow outdoors | Jun 12 – Jul 27 |
| Winter squash & pumpkins | Sow outdoors | Jun 26 – Jul 27 |
| Snap beans | Sow outdoors | Jun 12 – Jul 2 |
| Sweet corn | Sow outdoors | Jun 12 – May 30 |
| Watermelon & cantaloupe | Sow outdoors | Jun 26 – Jul 27 |
| Okra | Sow outdoors | Jun 19 – Jul 12 |
| Peas | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Potatoes | Plant outdoors (spring) | Apr 26 – Jun 26 |
| Onions | Start seeds indoors (spring) | Mar 15 – Apr 11 |
| Onions | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (spring) | Apr 8 – May 12 |
| Broccoli | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (fall) | May 20 – May 30 |
| Broccoli | Transplant outdoors (fall) | Jun 19 – Jun 30 |
| Cabbage | Start seeds indoors (spring) | Mar 29 – Apr 26 |
| Cabbage | Transplant outdoors (spring) | Apr 26 – May 27 |
| Cabbage | Start seeds indoors (fall) | May 10 – Jun 9 |
| Cabbage | Transplant outdoors (fall) | Jun 9 – Jul 10 |
| Leaf lettuce | Sow outdoors (spring) | Apr 26 – Jul 12 |
| Leaf lettuce | Sow outdoors (fall) | Jun 9 – Jul 26 |
| Spinach | Sow outdoors (spring) | Apr 19 – Jun 2 |
| Spinach | Sow outdoors (fall) | Jun 26 – Jul 31 |
| Radishes | Sow outdoors (spring) | Apr 26 – Jun 16 |
| Radishes | Sow outdoors (fall) | Jun 9 – Aug 10 |
| Kale | Sow outdoors (spring) | May 13 – Jun 2 |
| Kale | Sow outdoors (fall) | Jun 2 – Jul 10 |
| Carrots | Sow outdoors (spring) | May 27 – Jul 12 |
| Carrots | Sow outdoors (fall) | May 10 – Jun 25 |
| Garlic | Plant outdoors (fall) | Sep 9 – Oct 10 |
Where these dates come from
ZIP code 03583 is matched to the NOAA station Whitefield Mt Washington Ap, NH, 8.2 km away, at 1,074 ft elevation (215 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Whitefield Mt Washington Ap, NH (used) | 1,074 ft | May 27 | Sep 19 |
| Jefferson, NH | 1,235 ft | May 8 | Oct 1 |
| Lancaster, NH | 860 ft | May 18 | Sep 30 |
| York Pond, NH | 1,519 ft | May 23 | Sep 22 |
Frost dates near Jefferson
- Whitefield, NH 03598 · last May 27, first Sep 19
- Lancaster, NH 03584 · last May 18, first Sep 30
- Randolph, NH 03593 · last May 23, first Sep 22
- Bretton Woods, NH 03575 · last May 18, first Oct 1
- Twin Mountain, NH 03595 · last May 24, first Sep 18
- Lunenburg, VT 05906 · last May 24, first Sep 18
- Gilman, VT 05904 · last May 18, first Sep 30
- Groveton, NH 03582 · last May 18, first Sep 30
Frequently asked questions
- When is the last frost in Jefferson, NH?
- For ZIP code 03583, the average last spring frost (32°F) is May 27, based on NOAA 1991-2020 climate normals for the Whitefield Mt Washington Ap, NH weather station. There is a 1-in-10 chance of a frost after June 10.
- When is the first frost in Jefferson, NH?
- The average first fall frost (32°F) is September 19. There is a 1-in-10 chance of frost by September 8, so tender plants are at risk from that point on.
- How long is the growing season in 03583?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 116 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.