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Will it freeze in Belfast in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Wed, Nov 11: 29°F (Wed, Nov 11, 6:00 PM EST to Thu, Nov 12, 6:00 AM EST).
Tonight: forecast low 56°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 56°F Above 36°F · Mostly Cloudy then Slight Chance Light Rain
- Fri, Nov 6 47°F Above 36°F · Light Rain
- Sat, Nov 7 40°F Above 36°F · Light Rain Likely
- Sun, Nov 8 36°F Frost possible · Slight Chance Light Rain
- Mon, Nov 9 33°F Frost possible · Partly Cloudy
- Tue, Nov 10 34°F Frost possible · Partly Cloudy
- Wed, Nov 11 29°F 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 Belfast
The median first fall hard-freeze date (28°F) is October 19, from NOAA’s 1991–2020 Climate Normals at Belfast. 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 9 · May 21 · Jun 1 | Sep 15 · Sep 27 · Oct 8 | 128 days |
| 32°F freeze | Apr 28 · May 7 · May 21 | Sep 24 · Oct 5 · Oct 20 | 151 days |
| 28°F hard freeze | Apr 13 · Apr 27 · May 6 | Oct 3 · Oct 19 · Nov 3 | 174 days |
Average high temperature by month
1991–2020 normals at Belfast
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 Belfast, ME come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Belfast (station USC00170480, elevation 20 ft), 2.8 mi from Belfast. 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 Belfast
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Rockland, ME | 22 mi | Apr 27 | Oct 19 |
| Brewer, ME | 29 mi | May 4 | Oct 4 |
| Ellsworth, ME | 29 mi | May 8 | Oct 9 |
| Bangor, ME | 30 mi | May 4 | Oct 4 |
| Waterville, ME | 32 mi | May 2 | Oct 10 |
| Augusta, ME | 35 mi | Apr 27 | Oct 16 |
| Old Town, ME | 39 mi | May 13 | Sep 28 |
| Gardiner, ME | 41 mi | May 1 | Oct 11 |
| Bath, ME | 53 mi | May 10 | Oct 6 |
| Lewiston, ME | 62 mi | Apr 25 | Oct 19 |
Frequently asked questions
When is the last frost in Belfast?
On average, the last spring frost (32°F) in Belfast is around May 7. In about 1 year in 10 it comes after May 21, and in 9 years in 10 it comes after April 28.
When is the first frost in Belfast?
The first fall frost (32°F) usually arrives around October 5. There’s a 10% chance of a freeze by September 24 and a 90% chance by October 20.
Can it frost in Belfast 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 21.
What growing zone is Belfast?
Belfast is in USDA Plant Hardiness Zone 5b (average annual extreme minimum temperature −15 to −10°F), based on the 2023 USDA map for ZIP code 04915. See growing zones in Maine.
More: all Maine frost dates · Maine growing zones · frost vs. freeze