Frost dates / Connecticut / Bristol

Frost dates in Bristol, CT

The station on this page is BURLINGTON, CT US (USC00060973), 7.8 miles from the city point. Population in the Census 2024 estimate is 62,195.

Zone 6bUSDA average annual extreme minimum -5°F to 0°F, from ZIP 06010 (0 miles from the city point used on this page).

Median last 32°F is April 25. Median first 32°F is October 18. The 50% growing-season length is 172 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

Probability	Date	How to read it
90%	April 12	Earlier date. A last 32°F on or after this day is common.
50%	April 25	Median.
10%	May 10	Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

Probability	Date	How to read it
10%	October 4	Earlier date. A first 32°F on or before this day is uncommon.
50%	October 18	Median.
90%	November 1	Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this long	Days
10%	192
50%	172
90%	151

28°F threshold

	10%	50%	90%
Last, on or after	April 29	April 13	April 2
First, on or before	October 14	October 30	November 14
Season at least	217 days	197 days	175 days

36°F threshold

	10%	50%	90%
Last, on or after	May 22	May 6	April 24
First, on or before	September 26	October 6	October 20
Season at least	170 days	152 days	131 days

Station BURLINGTON, CT US (USC00060973). Completeness flag R, 24 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 153.9 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Check a crop against this station

Bristol, CT

Zone 6bAverage annual extreme minimum -5°F to 0°F

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Connecticut. Nearest qualified station: BURLINGTON, CT US (USC00060973), 7.8 miles. Median last 32°F April 25. Median first 32°F October 18. The 50% growing-season length is 172 days.

Open the ZIP page

32°F probabilities at this station

	10%	50%	90%
Last 32°F on or after	May 10	April 25	April 12
First 32°F on or before	October 4	October 18	November 1

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

A wall calendar surrounded by vegetables, herbs, seed packets, and watering cans.

Planting calendar

Frost dates for Connecticut are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.

Date checks use your device’s calendar and appear after the page loads.