Frost dates 2026–2027

Frost dates for Bristol, Connecticut

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Burlington, 7.8 mi away (close match).

Last spring frostApr 25
First fall frostOct 18
172 frost-free days
Last spring frostApr 251 year in 10 after May 10
First fall frostOct 181 year in 10 by Oct 4
Growing season172 daysbetween median 32°F dates
Hardiness zoneZone 6b−5 to 0°F average extreme low

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Will it freeze in Bristol 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 61°F. Above 36°F.

NWS forecast period: Thu, Nov 5, 6:00 PM EST to Fri, Nov 6, 6:00 AM EST.

2 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.

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 Bristol

The median first fall hard-freeze date (28°F) is October 30, from NOAA’s 1991–2020 Climate Normals at Burlington. This is the 50% probability date, not a forecast for this year.

TemperatureLast 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 24 · May 6 · May 22 Sep 26 · Oct 6 · Oct 20 152 days
32°F freeze Apr 12 · Apr 25 · May 10 Oct 4 · Oct 18 · Nov 1 172 days
28°F hard freeze Apr 2 · Apr 13 · Apr 29 Oct 14 · Oct 30 · Nov 14 197 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00060973. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Burlington

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 Bristol, CT come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Burlington (station USC00060973, elevation 505 ft), 7.8 mi from Bristol. 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 Bristol

CityDistanceLast spring frostFirst fall frost
New Britain, CT 8.1 mi Apr 17 Oct 26
Waterbury, CT 9.9 mi Apr 26 Oct 16
Meriden, CT 12 mi Apr 26 Oct 16
Torrington, CT 14 mi May 8 Oct 5
Naugatuck, CT 14 mi Apr 18 Oct 26
Hartford, CT 14 mi Apr 17 Oct 26
Middletown, CT 17 mi Apr 26 Oct 16
Ansonia, CT 24 mi Apr 25 Oct 17
New Haven, CT 25 mi Apr 17 Oct 27
Derby, CT 25 mi Apr 25 Oct 17

Frequently asked questions

When is the last frost in Bristol?

On average, the last spring frost (32°F) in Bristol is around April 25. In about 1 year in 10 it comes after May 10, and in 9 years in 10 it comes after April 12.

When is the first frost in Bristol?

The first fall frost (32°F) usually arrives around October 18. There’s a 10% chance of a freeze by October 4 and a 90% chance by November 1.

Can it frost in Bristol 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 6.

What growing zone is Bristol?

Bristol 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 06010. See growing zones in Connecticut.

More: all Connecticut frost dates · Connecticut growing zones · UV index today in Bristol · frost vs. freeze