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Will it freeze in Dover in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Mon, Nov 9: 32°F (Mon, Nov 9, 6:00 PM EST to Tue, Nov 10, 6:00 AM EST).
Tonight: forecast low 59°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.
4 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 59°F Above 36°F · Mostly Cloudy then Chance Light Rain
- Fri, Nov 6 53°F Above 36°F · Light Rain
- Sat, Nov 7 41°F Above 36°F · Light Rain
- Sun, Nov 8 35°F Frost possible · Partly Cloudy
- Mon, Nov 9 32°F Freeze · Mostly Clear
- Tue, Nov 10 34°F Frost possible · Mostly Clear
- Wed, Nov 11 26°F Hard freeze · Partly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Dover
The median first fall hard-freeze date (28°F) is October 23, from NOAA’s 1991–2020 Climate Normals at Durham 2 N. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | May 4 · May 15 · May 28 | Sep 17 · Sep 29 · Oct 11 | 135 days |
| 32°F freeze | Apr 23 · May 3 · May 16 | Sep 27 · Oct 10 · Oct 25 | 158 days |
| 28°F hard freeze | Apr 6 · Apr 20 · May 3 | Oct 7 · Oct 23 · Nov 6 | 184 days |
Average high temperature by month
1991–2020 normals at Durham 2 N
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Dover, NH come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Durham 2 N (station USW00054794, elevation 119 ft), 2.4 mi from Dover. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Dover
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Somersworth, NH | 4.3 mi | Apr 30 | Oct 9 |
| Rochester, NH | 9.3 mi | Apr 30 | Oct 9 |
| Portsmouth, NH | 9.9 mi | May 4 | Oct 8 |
| Sanford, ME | 17 mi | May 16 | Sep 30 |
| Amesbury, MA | 24 mi | May 1 | Oct 12 |
| Newburyport, MA | 26 mi | May 3 | Oct 8 |
| Haverhill, MA | 30 mi | May 1 | Oct 12 |
| Biddeford, ME | 30 mi | May 9 | Oct 3 |
| Manchester, NH | 32 mi | Apr 30 | Oct 11 |
| Saco, ME | 33 mi | Apr 26 | Oct 15 |
Frequently asked questions
When is the last frost in Dover?
On average, the last spring frost (32°F) in Dover is around May 3. In about 1 year in 10 it comes after May 16, and in 9 years in 10 it comes after April 23.
When is the first frost in Dover?
The first fall frost (32°F) usually arrives around October 10. There’s a 10% chance of a freeze by September 27 and a 90% chance by October 25.
Can it frost in Dover after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after May 15.
What growing zone is Dover?
Dover is in USDA Plant Hardiness Zone 6a (average annual extreme minimum temperature −10 to −5°F), based on the 2023 USDA map for ZIP code 03820. See growing zones in New Hampshire.
More: all New Hampshire frost dates · New Hampshire growing zones · UV index today in Dover · frost vs. freeze