Data Date: April

A bright sun illuminates tall grasses

April 2026 – Very Warm and Dry Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 57.4o F, which is 3.0o F above the 1991-2020 average value of 54.4o F (Figure 1).  April 2026 was the 6th warmest April since observations began in 1895.  At the Wilmington, Dover, and Georgetown Airports (Figure 2a, 2b, 2c), an early spring cold snap from April 8th through the 9th resulted in low temperatures near or below freezing.  This cold period was followed by an extended warm spell from April 14th to 18th that saw temperatures reach above 90o F at all three locations.  A subsequent cold period from April 20th to 22nd saw damaging freezes across the state with temperatures once again falling below freezing. 

 

April Precipitation

Delaware’s statewide precipitation for April 2026 averaged 1.74 inches, 1.74 inches below the 1991-2020 average of 3.48 inches (Figure 3).  April 2026 was the 9th driest April since observations began in 1895. April was also the 9th month in a row with at or below normal precipitation for Delaware.

 

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperatures were uniformly warm across the State, with most locations seeing positive temperature departures of between 1o F and 4o F (Figure 4).  Precipitation was below normal across nearly the entire state with most stations recording negative departures of between 1 and 2 inches (Figure 5).

 

National Anomalies

Temperatures were above normal across the entire coterminous United States in April (Figure 6), except for the northern Plains.  The core of this country-wide warmth was found across the Ohio Valley with departures of between 7o and 9o F.  Precipitation was significantly below normal across the Southeast and Atlantic Coast (Figure 7), and above normal across the Great Lakes and much of the Midwest.  In general, the western one-half of the country saw varied precipitation and relatively small anomalies. 

 

Global Anomalies

April 2026 was the 4th warmest April on record for the globe since 1850.  Global temperatures were 2.02o F above the 1901-2000 mean.  Notably, all 10 of the warmest Aprils in the 1850–2026 record have occurred since 2016.  Of particular note this month were the warm temperatures across most of the continental United States, and the Arctic, while much below normal temperatures were found across much of Canada (Figure 8).

 

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Violet flowers contrasted against a golden sky

April 2025 – Warm with Near Normal Precipitation Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 56.2o F, which is 1.8o F above the 1991-2020 mean value of 54.4o F (Figure 1).  April 2025 was tied with April of 1985 as the 11th warmest April on record since 1895. 

April Precipitation

Delaware’s statewide precipitation for April 2025 averaged 3.63 inches, 0.15 inches above the 1991-2020 mean of 3.48 inches (Figure 2).  April 2025 precipitation was in the “normal” range of all April precipitation totals since 1895.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were uniformly positive across the entire State (Figure 3), with some stations reaching anomalies of over 3o F in both Kent and Sussex Counties.  Precipitation was near normal across the state with the largest positive anomalies found across southern Sussex County (Figure 4).   

National Anomalies

Temperatures were above normal across the entire United States, except for the north-central portions of the country where temperatures were near normal (Figure 5). Large temperature anomalies of 5o to 7o F were found across parts of the Southeast.  Precipitation varied across the country (Figure 6) with much of the central portions of the country seeing large positive precipitation anomalies of over 4 inches.  The 500 hPa height pattern for April showed an anomalous jet stream ridge across much of the eastern United States and the Pacific Northwest associated with the warm temperatures in these regions (Figure 7).

Global Anomalies

April 2025 ranked as the second warmest April on record for the globe since 1850.  Global temperatures were 2.20o F (1.22o C)  above the 1901-2000 mean.  Particular warmth was found across central and far eastern Asia (Figure 8).

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Warm sun in orange sky

April 2024 – Warm and Dry Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 55.7° F, which is 1.3° F above the 1991-2020 mean value of 54.4° F (Figure 1).  April’s temperature was tied with April 1915 and April 1981 as the 14th warmest since records began in 1895.   

April Precipitation

Delaware’s statewide precipitation for April 2024 averaged 2.43 inches, 1.05 inches below the 1991-2020 mean of 3.48 inches (Figure 2).  April’s precipitation was in the bottom one-third of values over the last 130 years.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were positive across the entire state (Figure 3) with most locations seeing positive anomalies of between 1° F  and 3° F during the month.  Precipitation anomalies were mixed across the state, with positive anomalies found across the northern one-half of Delaware and larger, negative departures covering Sussex County (Figure 4).

National Anomalies

Temperatures were above normal across nearly the entire country with positive anomalies of 5° to 7° F found in the Great Lakes Region (Figure 5). Only the Northwest portion of the country saw near or just below normal temperatures.  Precipitation departures were positive across the Great Lakes Region (Figure 6), while the northern Pacific Coast and southeast U.S. saw generally below-normal precipitation.  The 500 hPa height pattern for April showed no strong jet stream anomalies (Figure 7) across the U.S.

Global Anomalies

April 2024 ranked as the warmest April on record for the globe since 1850.  Global temperatures were 1.32° C (2.38° F) above the 1901-2000 mean.  Particular warmth was found across much of the Arctic and in portions of eastern Europe and eastern Asia (Figure 8).

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April 2023 – Very Warm with Above Normal Precipitation Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 58.8o F, which is 4.4o F above the 1991-2020 mean value of 54.4o F (Figure 1).  April 2023 was the 2nd warmest since observations began in 1895.

April Precipitation

Delaware’s statewide precipitation for April 2023 averaged 5.65 inches, 2.17 inches above the 1991-2020 mean of 3.48 inches (Figure 2).  This month’s precipitation was tied with 1928 as the 7th wettest since 1895.  Interestingly, most of the April precipitation fell during the final three days of the month. 

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were uniformly positive across the entire state (Figure 3) with many locations seeing anomalies of nearly 5o F.  Precipitation anomalies were consistently positive across the entire state, with many stations recording departures of more than four inches, especially in Kent County (Figure 4).   

National Anomalies

Temperatures were generally above normal across the northeastern United States (Figure 5), while the north-central and northwestern portions of the country saw below normal temperatures (Figure 5).  Precipitation departures were mixed across the country, with the largest positive precipitation anomalies found along the Atlantic and Gulf Coast regions (Figure 6). The 500 hPa height pattern for April shows a weak jet stream trough covering most of the western two-thirds of the United States, while much of the eastern one-third of the country was covered by a jet stream ridge, contributing to the temperature anomalies found across these regions (Figure 7).

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April 2022 – Cool and Wet Conditions Prevail Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 53.8° F, which is 0.6° F below the 1991-2020 mean value of 54.4° F  (Figure 1). Even with temperatures cooler than the 1991-2020 mean value,  April 2022 still saw temperatures in the top one-third of all years since  1895.  

April Precipitation

Delaware’s statewide precipitation for April 2022 averaged 3.98 inches,  0.50 inches above the 1991-2020 mean (Figure 2). This month’s precipitation total was in the top one-third of all years since records began in 1895. 

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were below normal across the entire state, with some stations seeing negative temperature anomalies of greater than  2° F (Figure 3). Precipitation was above normal across the northern two thirds of the state, with the largest positive departures found across New  Castle County (Figure 4).  

National Anomalies

Temperatures were below normal across most of the northern tier of the  United States, with some areas seeing negative departures of 7° – 10° F.  The southwest portion of the country saw above normal temperatures with some positive departures as much as 5° – 7° F scattered throughout the region (Figure 5). Precipitation anomalies varied greatly across the country (Figure 6), with very dry conditions across the southwestern portion of the nation. Wet conditions were found scattered throughout the country with very high precipitation amounts found across North Dakota and parts of Minnesota. The 500 hPa height pattern for April shows a jet stream trough located over much of northern North America and a jet stream ridge over both the southern Atlantic and Pacific coasts,  contributing to the temperature anomalies across those regions (Figure 7).

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Barley/Wheat Field under the Sun

April 2021 – Warm with Below Normal Precipitation Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 55.7o F, which is 2.2o F above the 1981-2010 mean value of 53.5o F (Figure 1).  April 2021 was the 13th warmest April since observations began in 1895.

April Precipitation

Delaware’s statewide precipitation for April 2021 averaged 2.25 inches, 1.39 inches below the 1981-2010 mean (Figure 2).  This placed this month’s precipitation total in the bottom one-third of all years since 1895.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were positive at most stations, with the largest positive anomalies found across New Castle County (Figure 3).  Precipitation was below normal at nearly all stations throughout the State with the largest negative anomalies found across eastern Kent County (Figure 4).

National Anomalies

Temperatures were generally below normal across the central portion  of the United States, and warmer than normal along both the Pacific and north-Atlantic coasts (Figure 5).  Precipitation anomalies varied greatly across the country with particularly dry conditions across most of the western half of the United States.  The Gulf Coast, from Louisiana east to Florida, saw much above normal precipitation (Figure 6).  The 500 hPa height pattern for April shows a jet stream ridge across the Pacific Coast and a weak jet stream trough across the central and eastern portions of the country (Figure 7), contributing to the overall temperature pattern.

 

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Rain on window

April 2020 – Cool and Moist Across Delaware

Posted on | by Dan Leathers

 

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 52.4o F, which is 1.1o F below the 1981-2010 mean value of 53.5o F (Figure 1).  April 2020 was the first month with below normal temperatures since November 2019.

April Precipitation

Delaware’s statewide precipitation for April 2020 averaged 4.09 inches, 0.45 inches above the 1981-2010 mean (Figure 2).  This placed the April 2020 precipitation amount in the top one-third of all years since 1895.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were below normal throughout the State (Figure 3), with most stations between 2o and  4o F below the 30-year mean.  Precipitation was above normal at all locations, with the largest positive anomalies of between one and two inches across Kent and New Castle Counties (Figure 4).

National Anomalies

Temperatures were below normal across the eastern two-thirds of the U.S., except near the Gulf Coast states. Departures were generally between  1o to 5o F below normal in this area.  Positive temperature anomalies were found across much of the western and southwestern portions of the United States (Figure 5).  Precipitation was generally above normal in the eastern one-third of the United States and below normal across the west, except for large positive anomalies across southern California (Figure 6).  The 500 hPa height pattern for April showed a strong trough dominating the eastern two-thirds of the country (Figure 7) leading to the cooler temperatures across our region.

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A New Statewide 24-Hour Precipitation Record for Delaware!

Posted on | by Dan Leathers

It’s been awhile, but it’s now official. Delaware has a new 24 hour precipitation record. Also, this is the first state climate record in Delaware using one of our DEOS stations! We hope you’ll take a look at the report to find out more.

Rainfall over a 24-hour period in Delaware has broken the state’s record. Between September 28–29, 2016, near Harbeson,…

Posted by NOAA National Centers for Environmental Information on Tuesday, April 28, 2020

Spring 2019 – Warm Temperatures and Near Normal Precipitation Across Delaware

Posted on | by Dan Leathers

Spring Temperatures

Spring Temperatures Preliminary data indicates that spring temperatures averaged 55.8°F, 2.4°F above the 30-year “normal” of 53.4°F (Figure 1). Spring 2019 is tied with 1945 and 2011 as the 7th warmest since records began in 1895.

Spring Precipitation

Spring Precipitation The statewide mean precipitation of 12.10 inches was 0.4 inches above the 1981-2010 normal of 11.70 inches (Figure 2). This value placed the spring of 2019 in the wettest one-third of years since 1895.

Statewide Spatial Averages

Statewide Spatial Anomalies Data from the Delaware Environmental Observing System (DEOS) show that spring temperature anomalies were above normal across the entire State (Figure 3). Spring precipitation anomalies varied significantly across the state, but were all above normal (Figure 4). Anomalies were greater than three inches at several of the DEOS stations.

National Anomalies

National Anomalies Above normal spring temperatures were found across the southern Atlantic coast of the U.S. from Florida through the Mid-Atlantic Region (Figure 5), while colder than normal temperatures were found across the north-central portions of the country. Precipitation varied greatly across the continental United States, with the Mid-Atlantic Region generally seeing above normal values (Figure 6).

Positive 500 hPa height anomalies were present over the Mid-Atlantic Region during the spring season, indicative of anomalous ridging with enhanced flow from the south and moisture transport into our State (Figure 7). This anomalous flow helped to make the season warmer and wetter than normal.

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April 2019 – Near Record Warm Temperatures and Near Normal Precipitation Across Delaware

Posted on | by Dan Leathers

April Temperatures

Preliminary data indicates that the statewide average temperature in April was 58.0°F, which is 4.5°F above the 1981-2010 mean value of 53.5°F (Figure 1). This places April 2019 as the 2nd warmest since records began in 1895.

April Precipitation

Delaware’s statewide precipitation for April 2019 averaged 3.40 inches, 0.28 inches below the 1981-2010 mean (Figure 2). Delaware’s April precipitation was in the middle one-third of values for the last 125 years.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were uniformly above normal across the entire state (Figure 3), with many stations seeing anomalies of greater than 4.0°F. Precipitation departures varied depending upon location (Figure 4) with below normal precipitation in the north, and above normal precipitation values across the south.

National Anomalies

Most of the United States saw positive temperature anomalies during April, with the Mid-Atlantic Region and portions of California seeing the largest temperature departures (Figure 5). Much of the country saw above normal precipitation, except for the Great Plains, California and the Southwest (Figure 6).
The 500 hPa height pattern for April showed anomalous ridging of the jet stream over our region leading to enhanced southerly flow and higher than normal temperatures (Figure 7).

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