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Will it freeze in Waltham in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Wed, Nov 11: 32°F (Wed, Nov 11, 6:00 PM EST to Thu, Nov 12, 6:00 AM EST).
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 55°F Above 36°F · Light Rain
- Sat, Nov 7 44°F Above 36°F · Light Rain Likely
- Sun, Nov 8 39°F Above 36°F · Mostly Clear
- Mon, Nov 9 37°F Above 36°F · Mostly Clear
- Tue, Nov 10 38°F Above 36°F · Mostly Clear
- Wed, Nov 11 32°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 Waltham
The median first fall hard-freeze date (28°F) is October 25, from NOAA’s 1991–2020 Climate Normals at Bedford Hanscom Field. 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 28 · May 10 · May 23 | Sep 17 · Oct 1 · Oct 13 | 143 days |
| 32°F freeze | Apr 13 · Apr 28 · May 12 | Sep 28 · Oct 10 · Oct 28 | 165 days |
| 28°F hard freeze | Apr 1 · Apr 12 · Apr 29 | Oct 7 · Oct 25 · Nov 8 | 194 days |
Average high temperature by month
1991–2020 normals at Bedford Hanscom Field
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 Waltham, MA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Bedford Hanscom Field (station USW00014702, elevation 133 ft), 6.1 mi from Waltham. 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 Waltham
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Watertown, MA | 3.7 mi | Apr 19 | Oct 23 |
| Newton, MA | 4.3 mi | Apr 19 | Oct 23 |
| Cambridge, MA | 6.2 mi | Apr 19 | Oct 23 |
| Medford, MA | 7.5 mi | Apr 4 | Nov 9 |
| Somerville, MA | 7.5 mi | Apr 4 | Nov 9 |
| Woburn, MA | 8.1 mi | Apr 25 | Oct 17 |
| Everett, MA | 9.9 mi | Apr 4 | Nov 9 |
| Malden, MA | 9.9 mi | Apr 4 | Nov 9 |
| Melrose, MA | 11 mi | Apr 25 | Oct 17 |
| Chelsea, MA | 11 mi | Apr 4 | Nov 9 |
Frequently asked questions
When is the last frost in Waltham?
On average, the last spring frost (32°F) in Waltham is around April 28. In about 1 year in 10 it comes after May 12, and in 9 years in 10 it comes after April 13.
When is the first frost in Waltham?
The first fall frost (32°F) usually arrives around October 10. There’s a 10% chance of a freeze by September 28 and a 90% chance by October 28.
Can it frost in Waltham 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 10.
What growing zone is Waltham?
Waltham 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 02451. See growing zones in Massachusetts.
More: all Massachusetts frost dates · Massachusetts growing zones · UV index today in Waltham · frost vs. freeze