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Frost Dates and Planting Windows in Delaware

The 32°F frost dates at the 7 weather stations in Delaware with NOAA's 1991–2020 Climate Normals, and the planting windows they give. These are long-term statistics, not a forecast. For the dates at the station nearest you, enter your ZIP code.

The planner uses the weather station nearest your ZIP code.

Frost dates across Delaware

Each risk level uses a date with a set chance of frost. In spring, it's the chance of a 32°F frost on or after the last-frost date. In fall, it's the chance of the first 32°F frost on or before the first-frost date. At the Typical level (30%), the last frost ranges from April 2 to April 18 across the state, and the first frost from October 24 to November 7.

32°F frost dates: earliest and latest among 7 stations, by risk level
Risk levelEarliest last frostLatest last frostEarliest first frostLatest first frost
Conservative (10%)April 9LEWES, DE USApril 28GREENWOOD 2NE, DE USOctober 14GREENWOOD 2NE, DE USNovember 1LEWES, DE US
Typical (30%)April 2LEWES, DE USApril 18GREENWOOD 2NE, DE USOctober 24GREENWOOD 2NE, DE USNovember 7LEWES, DE US
Aggressive (50%)March 29LEWES, DE USApril 11GREENWOOD 2NE, DE USOctober 30GREENWOOD 2NE, DE USNovember 14LEWES, DE US

Growing season length

The growing season is the stretch between the last spring frost and the first fall frost at 32°F. NOAA gives it as a length with a chance of being at least that long. Each risk level uses the length with that chance of a shorter season, so Conservative shows the shortest lengths.

Growing season at 32°F: shortest and longest among 7 stations
Risk levelShortestLongest
Conservative (90% chance of at least this long)177 daysGREENWOOD 2NE, DE US213 daysLEWES, DE US
Typical (70% chance of at least this long)191 daysGREENWOOD 2NE, DE US224 daysLEWES, DE US
Aggressive (50% chance of at least this long)200 daysGREENWOOD 2NE, DE US231 daysLEWES, DE US
Number of stations by growing season length, Typical (70% chance of at least this long)
Growing seasonStations
180–199 days1
200–219 days5
220–239 days1

Planting windows across Delaware

For each crop, the earliest start and the latest end of its Typical windows among the stations. A window at any one station is shorter and falls inside this span. Transplant dates are for seedlings.

Typical planting windows (30% frost dates): earliest start and latest end among stations
Crop and taskEarliest startLatest endStations
Basil: Transplant outdoorsApril 16May 27 of 7
Bean: Sow outdoorsApril 2April 187 of 7
Beet: Sow outdoorsMarch 5April 187 of 7
Beet: Sow for fallAugust 1September 187 of 7
Broccoli: Transplant outdoorsMarch 5April 47 of 7
Broccoli: Transplant for fallJuly 22September 187 of 7
Brussels sprouts: Transplant outdoorsMarch 5April 47 of 7
Brussels sprouts: Transplant for fallJuly 2September 287 of 7
Cabbage: Transplant outdoorsMarch 5April 47 of 7
Cabbage: Transplant for fallJuly 17September 187 of 7
Cantaloupe: Transplant outdoorsApril 16May 27 of 7
Cantaloupe: Sow outdoorsApril 16May 27 of 7
Carrot: Sow outdoorsMarch 5April 187 of 7
Carrot: Sow for fallJuly 22September 87 of 7
Cucumber: Transplant outdoorsApril 9April 257 of 7
Cucumber: Sow outdoorsApril 2April 187 of 7
Eggplant: Transplant outdoorsApril 16May 27 of 7
Garlic: Plant for fallOctober 24November 217 of 7
Lettuce: Transplant outdoorsMarch 5April 47 of 7
Lettuce: Sow outdoorsMarch 5April 47 of 7
Lettuce: Sow for fallJuly 22September 287 of 7
Onion: Transplant or plant setsMarch 5April 47 of 7
Peas: Sow outdoorsMarch 5April 47 of 7
Peas: Sow for fallJuly 30September 187 of 7
Pepper: Transplant outdoorsApril 16May 27 of 7
Potato: Plant seed potatoesMarch 5April 187 of 7
Pumpkin: Sow outdoorsApril 16May 27 of 7
Radish: Sow outdoorsMarch 5April 47 of 7
Radish: Sow for fallSeptember 5October 187 of 7
Spinach: Transplant outdoorsMarch 5April 47 of 7
Spinach: Sow outdoorsMarch 5April 47 of 7
Spinach: Sow for fallAugust 11October 17 of 7
Summer squash: Transplant outdoorsApril 9April 257 of 7
Summer squash: Sow outdoorsApril 2April 187 of 7
Sweet corn: Sow outdoorsApril 2April 187 of 7
Sweet potato: Plant slipsApril 9May 27 of 7
Tomato: Transplant outdoorsApril 16May 27 of 7
Turnip: Sow outdoorsMarch 5April 47 of 7
Turnip: Sow for fallAugust 11September 287 of 7
Watermelon: Transplant outdoorsApril 16May 27 of 7
Watermelon: Sow outdoorsApril 16May 27 of 7

Weather stations in Delaware

Every station in Delaware with NOAA frost-date normals, with its Typical 32°F frost dates and growing season.

Data sources

NOAA U.S. Climate Normals, frost dates, 1991–2020 normals, version 1.0.1
Files: us-climate-normals_1991-2020_v1.0.1_annualseasonal_multivariate_by-station_c20230404.tar.gz, inventory_30yr.txt from NOAA NCEI. Retrieved October 10, 2026.