Delaware’s Climate

Delaware map
The State of Delaware is located in the mid-Atlantic United States and comprises approximately two-thirds of the Delmarva Peninsula .

The State of Delaware lies along the Atlantic coast of the United States, occupying the northern two-thirds of the Delmarva Peninsula. It is the second smallest of the United States with a land area of 1,982 mi². It is surrounded by water bodies including the Atlantic Ocean and Delaware Bay to the east, and Chesapeake Bay to the west.

The State is situated in a transition zone between humid subtropical climate conditions to the south and humid continental conditions to the north. The moderating effects of the surrounding water bodies lessen temperature extremes compared to nearby interior locations. Even so, the State has a continental climate, with cold winter temperatures, hot summers and ample precipitation throughout the year. However, annual precipitation amounts can vary greatly from one year to another.


Delaware Average Annual Temperature 1895-2019. Data from NOAA Climate at a Glance. [link]

Mean annual temperatures across the State range from 54.0 ° F in northern New Castle County to 58.1 ° F along the Atlantic coast of southern Delaware. Average annual precipitation is approximately 45” statewide.

Precipitation and Storms

annual precipitation graph for Delaware 1895-2020
Annual precipitation totals (inches) for Delaware for 1895-2020.

Mean annual precipitation for Delaware is about 45 inches with large inter-annual variability.

The State is often affected by seasonally occurring severe weather including winter and spring nor-easters that can drop heavy snow and cause coastal flooding, autumn tropical systems with high winds, coastal flooding and heavy rainfall and spring and summer severe thunderstorms.

Delaware Climate Normals

Browse and download the Delaware 1981-2010 Climate Normals here.

Delaware Annual Average Temperature spatially interpolated from NCEI 1981 – 2010 Normal Data.
Delaware Annual Average Precipitation spatially interpolated from NCEI 1981 – 2010 Normal Data.

All-Time Climate Extremes for DE

Variable Value Location Date Station ID Status
24-hr Precipitation 12.48 in. Harbeson September 28-29,2016 DWAR* NSA
24-hr Snow Fall 25.0 in. Dover February 19, 1979 072730 E
Monthly Snowfall 46.9 in. Bear 2 SW February 1-28, 2010 071200 NSA
Seasonal Snowfall 72.7 in. Bear 2 SW July 1, 2009 – June30, 2010 071200 NSA
Snow Depth 28 in. Greenwood 2.9 SE Feb 7, 2010 CoCoRaHS DE-SS-7 NSA
Maximum Temperature 110 °F Millsboro July 21, 1930 076020 E
Minimum Temperature -17 °F Millsboro January 17, 1893 076020 E

Credit: NOAA Climate Services and Monitoring Division. For more information, please visit

* This measurement was recorded at DEOS Mesonet Station DWAR (NWSLI WARD1)

E – Value is unchanged from previous extremes tables last updated by NCDC between 1998 and 2006. Value exceeds all other valid values.
N – Value is changed from extremes tables last updated by NCDC between 1998 and 2006. Value exceeds all other valid values.
S – Value has been officially reviewed by a State Climate Extremes Committee.
A – Additional information is available. Official value may be exceeded by a widely accepted unofficial value that is not supported by a direct, calibrated observation (e.g., estimates, uncalibrated instruments, anecdotal reports).
1 – Value ties values from earlier dates.