Skip to content

Delaware Frost Dates: Last and First Frost by Town

7 NOAA weather stations · 1991–2020 U.S. Climate Normals · Data updated 2026-10-29

Quick answer

Across Delaware's 7 NOAA stations with regular frost, the median last spring frost is April 7 and the median first fall frost is November 4. Last frost dates range from March 29 at Lewes to April 11 at Greenwood 2NE, so enter your ZIP code below for the station nearest you.

How frost dates vary across Delaware

  • Safety margin: the median 10%-risk date (April 21) is about 14 days after the median last frost. Waiting until then cuts the chance of a killing frost on tender transplants from 1 in 2 to 1 in 10.

All 7 stations in Delaware

Last frost and first frost are medians: a 50% chance of a 32°F night after (spring) or before (fall) that date. 10% risk is the spring date with only a 1-in-10 chance of a later frost. Click a column to sort.
Dover30Apr 4Apr 17Nov 4214
Georgetown Sussex County Airport51Apr 4Apr 16Nov 6217
Greenwood 2NE45Apr 11Apr 28Oct 30200
Lewes10Mar 29Apr 9Nov 14231
Newark Agricultural Farm106Apr 7Apr 21Nov 2208
Wilmington New Castle County Airport79Apr 7Apr 21Nov 1209
Wilmington Porter Rsch270Apr 7Apr 24Nov 4209

Frequently asked questions

When is the last frost in Delaware?

The median last spring frost (32°F) across Delaware's NOAA weather stations is April 7, based on 1991–2020 climate normals. It ranges from March 29 at Lewes to April 11 at Greenwood 2NE. For a safer planting date, use the 10%-risk date; the state median for that is April 21.

When is the first frost in Delaware?

The median first fall frost across Delaware's stations is November 4. The earliest median first frost is October 30 at Greenwood 2NE, and the latest is November 14 at Lewes.

How long is the growing season in Delaware?

The median frost-free season is 209 days across Delaware's stations, from 200 days at Greenwood 2NE to 231 days at Lewes.

When should I plant tomatoes in Delaware?

Plant tomatoes outdoors after your local last frost, ideally after the 10%-risk date when nights stay above 50°F. At a typical Delaware station that means starting seeds indoors 6–8 weeks before April 7 and transplanting from about April 21. Check your ZIP code, because dates vary by weeks across the state.

How to use these dates

Frost dates are 30-year averages from NOAA, not forecasts. Use them to plan seed starting and planting, then watch the 10-day forecast as the date approaches. Cold air settles in valleys and low spots, so a garden at the bottom of a slope can frost a week or more later in spring than the nearest station shows.

Ready to plan? The planting calendar by ZIP code turns these dates into start-indoors, transplant and sowing dates for 30 crops.

Sources and method

Dates are the 32°F freeze probabilities published in the NOAA NCEI 1991–2020 U.S. Climate Normals for each station. Station names are NOAA's, lightly expanded for readability. See the methodology or download the full table.

Frost dates in other states