Frost dates for 03857Newmarket, NH
The average last spring frost in Newmarket is May 7 and the average first fall frost is October 4, giving a typical growing season of about 150 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Oct 4
- Growing season
- 150 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 186 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 7 · May 19 · Jun 1 | Sep 11 · Sep 24 · Oct 6 | 127 days | 100% |
| Frost / freeze (32°F) | Apr 25 · May 7 · May 19 | Sep 23 · Oct 4 · Oct 21 | 150 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 24 · May 7 | Oct 2 · Oct 19 · Nov 4 | 177 days | 100% |
Planting calendar for Newmarket
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 6 – Jun 12 |
| Tomatoes | Transplant outdoors | May 23 – Jun 14 |
| Peppers | Start seeds indoors | Apr 6 – May 7 |
| Peppers | Transplant outdoors | Jun 6 – Jul 7 |
| Eggplant | Start seeds indoors | Apr 23 – May 22 |
| Eggplant | Transplant outdoors | Jun 6 – Jul 7 |
| Cucumbers | Sow outdoors | Jun 6 – Jun 24 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 17 |
| Sweet corn | Sow outdoors | May 23 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 6 – Jul 7 |
| Okra | Sow outdoors | May 30 – Jun 22 |
| Peas | Sow outdoors (spring) | Apr 6 – May 22 |
| Potatoes | Plant outdoors (spring) | Apr 6 – Jun 6 |
| Onions | Start seeds indoors (spring) | Feb 23 – Mar 22 |
| Onions | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (spring) | Mar 19 – Apr 22 |
| Broccoli | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 03857 is matched to the NOAA station Durham 2 Ssw, NH, 4.1 km away, at 63 ft elevation (4 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Durham 2 Ssw, NH (used) | 63 ft | May 7 | Oct 4 |
| Durham, NH | 75 ft | May 8 | Oct 4 |
| Durham 2 N, NH | 119 ft | May 3 | Oct 10 |
| Epping, NH | 160 ft | May 7 | Oct 4 |
Frost dates near Newmarket
- Newfields, NH 03856 · last May 7, first Oct 4
- Durham, NH 03824 · last May 7, first Oct 4
- Lee, NH 03861 · last May 7, first Oct 4
- Stratham, NH 03885 · last May 4, first Oct 8
- Hampton, NH 03843 · last May 7, first Oct 4
- Greenland, NH 03840 · last May 4, first Oct 8
- Exeter, NH 03833 · last May 4, first Oct 8
- Epping, NH 03042 · last May 7, first Oct 4
Frequently asked questions
- When is the last frost in Newmarket, NH?
- For ZIP code 03857, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Durham 2 Ssw, NH weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Newmarket, NH?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 03857?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 150 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.