All maps are courtesy of the High Plains Regional Climate Center ACIS Climate Maps application (https://hprcc.unl.edu/maps.php?map=ACISClimateMaps).
Heating Degree Days (HDD) Base 65
What is a degree day?
Degree days are measures of how cold or warm a location is. A degree day compares the mean (the average of the high and low) outdoor temperatures recorded for a location to a standard temperature, usually 65° Fahrenheit (F) in the United States. The more extreme the outside temperature, the higher the number of degree days. A high number of degree days generally results in higher levels of energy use for space heating or cooling.
Heating degree days (HDD) are a measure of how cold the temperature was on a given day or during a period of days. For example, a day with a mean temperature of 40°F has 25 HDD. Two such cold days in a row have a total of 50 HDD for the two-day period.
1981-2010 NCEI HDD Normals for Wilmington, DE (station id: 13781)
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
1010 | 836 | 683 | 363 | 135 | 15 | 0 | 2 | 50 | 292 | 554 | 879 | 4819 |
NWS Eastern Region HDD
Cooling Degree Days (CDD) Base 65
What is a degree day?
Degree days are measures of how cold or warm a location is. A degree day compares the mean (the average of the high and low) outdoor temperatures recorded for a location to a standard temperature, usually 65° Fahrenheit (F) in the United States. The more extreme the outside temperature, the higher the number of degree days. A high number of degree days generally results in higher levels of energy use for space heating or cooling. Cooling degree days (CDD) are a measure of how hot the temperature was on a given day or during a period of days. A day with a mean temperature of 80°F has 15 CDD. If the next day has a mean temperature of 83°F, it has 18 CDD. The total CDD for the two days is 33 CDD.
1981-2010 NCEI CDD Normals for Wilmington, DE (station id: 13781)
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
0 | 0 | 1 | 11 | 67 | 231 | 367 | 316 | 134 | 18 | 0 | 0 | 1145 |
NWS Eastern Region CDD
Delaware experiences both short- and long-term droughts, which have direct impacts on water supply and availability, especially with regard to agriculture and irrigation. Below are the most current maps created by the US Drought Monitor (USDM). These maps will indicate the current drought using five classifications: abnormally dry (D0), showing areas that may be going into or are coming out of drought, and four levels of drought: moderate (D1), severe (D2), extreme (D3) and exceptional (D4).
For more detailed information on Delaware drought, please visit click here the US Drought Portal [drought.gov].
For questions or comments about these maps or other data, please contact us.