FrostDateCheck

Hartford, CT 06238 Frost Dates

Frost dates for Hartford, CT, ZIP 06238

Zone 6b

Typically, the last spring freeze lands around 04/19, roughly 234 days out. The first fall frost typically arrives around 10/22, about 186 frost-free days later.

Hartford sits in USDA Zone 6b (-5 to 0°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.

What to do before the first frost

Zone 6b around Hartford has about 8 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.

The actual range around Hartford's last frost

04/19 is the middle of 30 years of NOAA records, not a promise. Plant by 04/07 and you're betting against frost in roughly 9 years out of 10. 05/03 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Hartford compares

Hartford's growing season runs about 186 days, ranking 22,678 of 40,283 US ZIP codes measured here, longest to shortest. Within CT, it ranks 234 of 391.

Learn more

the frost range explains how to read the range around Hartford's dates instead of trusting one, and local microclimates explains what one yard in Hartford can differ from the 06238 normal.