Garden Yardstick

Frost Dates in Delaware

Across 7 NOAA weather stations in Delaware, the average last spring frost falls between March 29 at Lewes and April 11 at Greenwood 2NE. At a typical Delaware station it is around April 7, with the first fall frost around November 4 and a frost-free season of about 209 days.

Find the frost dates for your ZIP code

A typical Delaware season

What shapes frost dates in Delaware

  • The frost-free season ranges from 200 days at Greenwood 2NE to 231 days at Lewes.
  • Gardens in valleys and low spots, where cold air settles, often frost a week or more later in spring than the nearest station.

Frost dates at major airports

StationLast frostSafer dateFirst frostSeason (days)
Georgetown Sussex Co AirportApr 4Apr 16Nov 6217
Wilmington New Castle Co AirportApr 7Apr 21Nov 1209

All 7 weather stations in Delaware

StationElevation (ft)Last frostSafer dateFirst frostSeason (days)
Dover30Apr 4Apr 17Nov 4214
Georgetown Sussex Co Airport51Apr 4Apr 16Nov 6217
Greenwood 2NE45Apr 11Apr 28Oct 30200
Lewes10Mar 29Apr 9Nov 14231
Newark Ag Farm106Apr 7Apr 21Nov 2208
Wilmington New Castle Co Airport79Apr 7Apr 21Nov 1209
Wilmington Porter Rsch270Apr 7Apr 24Nov 4209

Last frost and first frost are averages (a 50% chance of frost later in spring or earlier in fall). Safer date is the spring date with only a 10% chance of a later frost.

Using these dates

Plant hardy crops like peas and spinach several weeks before your last frost, and tender crops like tomatoes and peppers after it, once nights stay above 50°F. The Seed Starting Calculator turns your frost date into sowing and planting dates, and When to Plant Tomatoes explains the timing in detail.

Data: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, 32°F threshold.

Frost dates in other states