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Will it freeze in Watertown in the next 7 nights?
No overnight lows at or below 32°F are forecast in Watertown during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 62°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.
1 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 62°F Above 36°F · Chance Light Rain
- Fri, Nov 6 56°F Above 36°F · Light Rain
- Sat, Nov 7 45°F Above 36°F · Light Rain Likely
- Sun, Nov 8 40°F Above 36°F · Mostly Clear
- Mon, Nov 9 37°F Above 36°F · Mostly Clear
- Tue, Nov 10 40°F Above 36°F · Mostly Clear
- Wed, Nov 11 33°F Frost possible · 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 Watertown
The median first fall hard-freeze date (28°F) is November 3, from NOAA’s 1991–2020 Climate Normals at Jamaica Plain. 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 | Apr 20 · May 2 · May 16 | Sep 30 · Oct 10 · Oct 25 | 161 days |
| 32°F freeze | Apr 6 · Apr 19 · May 3 | Oct 8 · Oct 23 · Nov 5 | 185 days |
| 28°F hard freeze | Mar 25 · Apr 5 · Apr 21 | Oct 19 · Nov 3 · Nov 19 | 210 days |
Average high temperature by month
1991–2020 normals at Jamaica Plain
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 Watertown, MA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Jamaica Plain (station USC00193890, elevation 95 ft), 5.3 mi from Watertown. 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 Watertown
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Newton, MA | 3.1 mi | Apr 19 | Oct 23 |
| Cambridge, MA | 3.1 mi | Apr 19 | Oct 23 |
| Waltham, MA | 3.7 mi | Apr 28 | Oct 10 |
| Somerville, MA | 4.3 mi | Apr 4 | Nov 9 |
| Medford, MA | 5.0 mi | Apr 4 | Nov 9 |
| Everett, MA | 6.8 mi | Apr 4 | Nov 9 |
| Malden, MA | 7.5 mi | Apr 4 | Nov 9 |
| Chelsea, MA | 7.5 mi | Apr 4 | Nov 9 |
| Woburn, MA | 8.1 mi | Apr 25 | Oct 17 |
| Boston, MA | 8.7 mi | Apr 4 | Nov 9 |
Frequently asked questions
When is the last frost in Watertown?
On average, the last spring frost (32°F) in Watertown is around April 19. In about 1 year in 10 it comes after May 3, and in 9 years in 10 it comes after April 6.
When is the first frost in Watertown?
The first fall frost (32°F) usually arrives around October 23. There’s a 10% chance of a freeze by October 8 and a 90% chance by November 5.
Can it frost in Watertown 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 2.
What growing zone is Watertown?
Watertown is in USDA Plant Hardiness Zone 6b (average annual extreme minimum temperature −5 to 0°F), based on the 2023 USDA map for ZIP code 02472. See growing zones in Massachusetts.
More: all Massachusetts frost dates · Massachusetts growing zones · UV index today in Watertown · frost vs. freeze