When Is the Last Frost in Connecticut?
The average last spring frost in Connecticut falls between April 12 and May 3 for most ZIP codes, with a statewide median of April 20. At the average date a later frost is still a coin flip, so tender plants wait for the safer 90% date.
| City | Last frost | 90% safe after | First frost | Growing season |
|---|---|---|---|---|
| Bridgeport | Apr 5 | Apr 17 | Nov 6 | 216 days |
| Stamford | Apr 17 | May 2 | Oct 23 | 188 days |
| New Haven | Apr 17 | May 1 | Oct 27 | 193 days |
| Hartford | Apr 17 | May 1 | Oct 26 | 191 days |
| Waterbury | Apr 26 | May 9 | Oct 16 | 175 days |
| Norwalk | Apr 17 | May 2 | Oct 23 | 188 days |
| Danbury | Apr 20 | May 6 | Oct 20 | 181 days |
| New Britain | Apr 17 | May 1 | Oct 26 | 191 days |
| Bristol | Apr 25 | May 10 | Oct 18 | 172 days |
| Meriden | Apr 26 | May 9 | Oct 16 | 175 days |
| Norwich | Apr 14 | Apr 30 | Oct 24 | 192 days |
| Danielson | Apr 25 | May 9 | Oct 19 | 176 days |
| Stonington | Apr 11 | Apr 26 | Oct 31 | 201 days |
| Bantam | May 8 | May 22 | Oct 5 | 151 days |
| Fenwick | Apr 6 | May 2 | Nov 17 | 221 days |
Last and first frost: 50% (median) dates of the last spring and first fall 32 °F night. 90% safe after: only a 10% chance of a later spring frost. First frost dates in January fall in the following winter. Each city uses the NOAA station nearest the ZIP code closest to its center.
Across all 23 Connecticut weather stations with frost records, median last frost dates run from April 5 at Bridgeport Sikorsky Mem AP, CT to May 11 at Falls Village, CT. Elevation, valleys that collect cold air and distance from large water bodies explain most of the spread, so a garden a few miles from a listed city can differ by a week or more. The ZIP code lookup above uses the same NOAA data as the frost date calculator for every US ZIP code.
When Is the First Frost in Connecticut?
The average first fall frost in Connecticut arrives between October 11 and October 31 for most ZIP codes, with a median of October 20. Tomatoes, peppers, basil and squash are damaged at 32 °F, so harvest or cover them before then.
Fall frost can come early: Bridgeport has a 10% chance of frost before October 25, Stamford has a 10% chance of frost before October 8 and New Haven has a 10% chance of frost before October 11. Hardy crops such as kale, spinach and cabbage tolerate light frosts and keep producing after the first frost date.
When to Plant Tomatoes in Connecticut?
Transplant tomatoes in Connecticut 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Apr 12 – Apr 19 in Bridgeport, Apr 24 – May 1 in Stamford and Apr 24 – May 1 in New Haven. Start seeds indoors 6 to 8 weeks before the last frost.
| City | Start seeds indoors | Transplant outdoors | Lowest-risk transplant |
|---|---|---|---|
| Bridgeport | Feb 8 – Feb 22 | Apr 12 – Apr 19 | after Apr 17 |
| Stamford | Feb 20 – Mar 6 | Apr 24 – May 1 | after May 2 |
| New Haven | Feb 20 – Mar 6 | Apr 24 – May 1 | after May 1 |
| Hartford | Feb 20 – Mar 6 | Apr 24 – May 1 | after May 1 |
| Waterbury | Mar 1 – Mar 15 | May 3 – May 10 | after May 9 |
| Norwalk | Feb 20 – Mar 6 | Apr 24 – May 1 | after May 2 |
| Danbury | Feb 23 – Mar 9 | Apr 27 – May 4 | after May 6 |
| New Britain | Feb 20 – Mar 6 | Apr 24 – May 1 | after May 1 |
| Bristol | Feb 28 – Mar 14 | May 2 – May 9 | after May 10 |
| Meriden | Mar 1 – Mar 15 | May 3 – May 10 | after May 9 |
| Norwich | Feb 17 – Mar 3 | Apr 21 – Apr 28 | after Apr 30 |
| Danielson | Feb 28 – Mar 14 | May 2 – May 9 | after May 9 |
| Stonington | Feb 14 – Feb 28 | Apr 18 – Apr 25 | after Apr 26 |
| Bantam | Mar 13 – Mar 27 | May 15 – May 22 | after May 22 |
| Fenwick | Feb 9 – Feb 23 | Apr 13 – Apr 20 | after May 2 |
Indoors: 6–8 weeks before the average last frost. Outdoors: 1–2 weeks after it. Lowest-risk: after the date with only a 10% chance of a later frost. Rules of thumb; check the 10-day forecast and wait for soil near 60 °F.
Tomatoes stall below about 50 °F at night and are killed by frost, so a week or two of waiting after the average date costs little. The tomato plant care guide covers light, watering and feeding once plants are in the ground.
What Can You Plant in Bridgeport and When?
Bridgeport's average last frost of April 5 anchors its spring planting calendar: peas and spinach go in from February 22, broccoli and lettuce transplants from March 8, and tomatoes, peppers and squash after April 12.
| Crop | Start seeds indoors | Plant outdoors | Frost tolerance |
|---|---|---|---|
| Peas | — | Feb 22 – Mar 8direct sow, 4–6 weeks before last frost | hardy |
| Spinach | — | Feb 22 – Mar 15direct sow, 3–6 weeks before last frost | hardy |
| Radishes | — | Mar 1 – Mar 15direct sow, 3–5 weeks before last frost | hardy |
| Onions (sets) | — | Mar 8 – Mar 22plant, 2–4 weeks before last frost | hardy |
| Potatoes | — | Mar 8 – Mar 22plant, 2–4 weeks before last frost | half-hardy |
| Broccoli & cabbage | Feb 8 – Feb 22 | Mar 8 – Mar 22transplant, 2–4 weeks before last frost | hardy |
| Lettuce | Feb 22 – Mar 8 | Mar 8 – Mar 22transplant, 2–4 weeks before last frost | hardy |
| Beets | — | Mar 8 – Mar 22direct sow, 2–4 weeks before last frost | half-hardy |
| Carrots | — | Mar 15 – Mar 22direct sow, 2–3 weeks before last frost | half-hardy |
| Tomatoes | Feb 8 – Feb 22 | Apr 12 – Apr 19transplant, 1–2 weeks after last frost | tender |
| Basil | Feb 8 – Feb 22 | Apr 12 – Apr 26transplant, 1–3 weeks after last frost | tender |
| Peppers | Jan 25 – Feb 8 | Apr 19 – Apr 26transplant, 2–3 weeks after last frost | tender |
| Eggplant | Jan 25 – Feb 8 | Apr 19 – Apr 26transplant, 2–3 weeks after last frost | tender |
| Green beans | — | Apr 12 – Apr 26direct sow, 1–3 weeks after last frost | tender |
| Sweet corn | — | Apr 12 – Apr 26direct sow, 1–3 weeks after last frost | tender |
| Cucumbers | Mar 8 – Mar 15 | Apr 12 – Apr 26transplant, 1–3 weeks after last frost | tender |
| Squash & zucchini | Mar 8 – Mar 15 | Apr 12 – Apr 26transplant, 1–3 weeks after last frost | tender |
| Watermelon | Mar 8 – Mar 15 | Apr 19 – Apr 26transplant, 2–3 weeks after last frost | tender |
Dates for Bridgeport (last frost Apr 5, NOAA station Bridgeport Sikorsky Mem AP, CT, 3 miles from ZIP 06608). General rules of thumb; wait for soil near 50 °F for most seeds and 60 °F for beans, corn and squash.
How Long Is the Growing Season in Connecticut?
The frost-free growing season in Connecticut lasts about 161 to 200 days for most ZIP codes, with a median of 181 days. Among the listed cities, Bantam has the shortest season at 151 days and Fenwick the longest at 221.
Season length decides which varieties ripen: compare it with the “days to maturity” on seed packets, counted from transplanting for tomatoes and peppers. NOAA stations in Connecticut range from 146 days at Falls Village, CT to 216 days at Bridgeport Sikorsky Mem AP, CT. Planning beds before the season starts helps in short seasons — a plant spacing calculator for vegetable beds shows how many transplants fit.
What Hardiness Zones Are in Connecticut?
Connecticut spans USDA hardiness zones 6a to 7b, with zone 6b the most common. Zones describe winter cold and decide which perennials survive, while frost dates set when to plant annual vegetables and flowers.
The Connecticut planting zone map with the zone of each city shows how the zones are spread across the state and which plants are hardy in all of them.
Frequently Asked Questions
- When is the last frost in Connecticut?
- The average last spring frost in Connecticut falls between April 12 and May 3 for most ZIP codes, with a statewide median of April 20. Among major cities it ranges from April 5 in Bridgeport to May 8 in Bantam.
- When is the last frost in Bridgeport, Connecticut?
- Bridgeport's average last spring frost is April 5, and by April 17 the chance of a later frost drops to 10%. Its first fall frost averages November 6, giving a 216-day growing season (NOAA station Bridgeport Sikorsky Mem AP, CT).
- When should you plant tomatoes in Connecticut?
- Transplant tomatoes in Connecticut 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Apr 12 – Apr 19 in Bridgeport, Apr 24 – May 1 in Stamford and Apr 24 – May 1 in New Haven. Start seeds indoors 6 to 8 weeks before the last frost.
- When is the first frost in Connecticut?
- The average first fall frost in Connecticut arrives between October 11 and October 31 for most ZIP codes, with a median of October 20. Harvest tender crops such as tomatoes, peppers and basil before then or cover them on cold nights.
- How long is the growing season in Connecticut?
- The frost-free growing season in Connecticut lasts about 161 to 200 days for most ZIP codes, with a median of 181 days, from 151 days in Bantam to 221 days in Fenwick.
Frost data: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (32 °F freeze dates by probability). ZIP code and city locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. Planting windows are general rules of thumb. PlantoScan is not affiliated with or endorsed by these agencies.