When is the last frost in Hartford, CT?

The average last spring frost (50% probability of 32°F) in Hartford is around April 17, based on NOAA/NCEI 1991–2020 normals at the Hartford Brainard Fld, CT station (3.3 mi away). Half of years it falls outside that date, so wait 1–2 weeks past it before setting out frost-tender plants.

When is the first fall frost in Hartford?

The average first fall frost in Hartford, CT is around October 26, giving roughly a 191-day frost-free growing season.

What planting zone is Hartford, CT?

Hartford is in USDA plant hardiness zone 6b (average annual extreme minimum temperature -5 to 0°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in Hartford?

In Hartford, CT the warmest month is July (avg high 84.6°F) and the coldest is January (avg low 20.3°F). It averages about 42.8″ of precipitation a year.

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Hartford, CT Planting Calendar & Frost Dates

USDA hardiness zone 6b · ZIP 06101 · elevation 6′ · NOAA & USDA data

Hartford is in USDA hardiness zone 6b (winters can dip to -5 to 0°F), with a growing season of about 191 days between the average last spring frost (April 17) and first fall frost (October 26). The warmest month is July (avg high 84.6°F); the coldest is January (avg low 20.3°F). It averages 42.8″ of precipitation a year. Start cool-season crops several weeks before the last frost; wait until after it for tomatoes, peppers and other tender crops.

Hardiness zone

min temp -5 to 0°F

Last spring frost

April 17

avg (50% prob, 32°F)

First fall frost

October 26

avg (50% prob, 32°F)

Growing season

191 days

frost-free window

Warmest month

July

avg high 84.6°F

Month-by-month typical weather in Hartford

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Hartford Brainard Fld, CT (3.3 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)	Snow (in)
January	36.8	20.3	28.6	2.9	–
February	39.5	22.1	30.8	2.6	–
March	47.6	29.6	38.6	3.5	–
April	60.1	40	50	3.8	–
May	70.9	50.1	60.5	3.4	–
June	79.6	59.8	69.7	3.9	–
July	84.6	65.7	75.2	3.9	–
August	83	64.2	73.6	3.5	–
September	75.6	56	65.8	4	–
October	63.7	44.3	54	4.2	–
November	52.1	34.6	43.3	3.4	–
December	41.7	25.9	33.8	3.8	–

What to plant when in Hartford

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: March 6 · Transplant out: April 24
Peppers	warm	Start seeds indoors: February 20 · Transplant out: May 1
Cucumbers	warm	Direct sow: April 24
Zucchini / squash	warm	Direct sow: April 24
Bush beans	warm	Direct sow: April 24
Sweet corn	warm	Direct sow: April 24
Basil	warm	Transplant out: April 24
Peas	cool	Sow (spring): March 13 · Sow (fall): August 31
Spinach	cool	Sow (spring): March 6 · Sow (fall): August 31
Lettuce	cool	Sow (spring): March 20 · Sow (fall): August 31
Kale	cool	Transplant (spring): March 27 · Sow (fall): August 17
Broccoli	cool	Transplant (spring): April 3
Carrots	cool	Sow (spring): March 27 · Sow (fall): August 17
Onions	cool	Transplant (spring): March 20
Potatoes	cool	Plant seed potatoes: April 3
Radishes	cool	Sow (spring): March 20 · Sow (fall): September 14

Dates are computed from Hartford's average frost dates using standard cool-/warm-season timing. They're a starting point — a cold spring, a warm microclimate, or a fast-maturing variety can shift them by a week or two.

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Gear that helps you plant on time

Some links below are Amazon affiliate links (tag theboringthin-20). If you buy through them we may earn a small commission at no extra cost to you — it keeps this almanac free. We only list generic, genuinely-useful categories.

Soil thermometer →Know when the ground is warm enough to sow — the honest signal, not the calendar.Seed-starting trays + dome →Start tomatoes & peppers indoors on the schedule below.Seedling heat mat →Warms the soil for faster, more even germination indoors.Floating row cover / frost cloth →Buys you 4–8°F to beat an early or late frost.Raised garden bed kit →Warms and drains faster in spring than in-ground soil.Garden gloves →Basic kit for transplant day.

Nearby cities in Connecticut

New Britain, CT Bristol, CT Middletown, CT Meriden, CT Waterbury, CT Norwich, CT New Haven, CT West Haven, CT

Sources & method. Hardiness zone: 2023 USDA Plant Hardiness Zone Map (PRISM Climate Group, Oregon State University). Frost dates & growing season: NOAA/NCEI 1991–2020 U.S. Climate Normals, nearest station with published freeze normals — Hartford Brainard Fld, CT, 3.3 mi (confidence: high). Monthly weather normals: Hartford Brainard Fld, CT, 3.3 mi (confidence: high). ZIP centroid from U.S. Census 2023 ZCTA data. Frost dates are the 50%-probability date — half of years frost occurs outside the stated date. Nothing here is invented; where the nearest station is far, we say so. Last updated 2026-07-22.