November Archives - Page 2 of 2 - Delaware Climate Office

Temperature and Precipitation Both Above Normal Across Delaware During 2015

Posted on January 15, 2016 | by Dan Leathers

Annual Temperatures

Statewide mean annual temperature in 2015 was 56.4°F according to preliminary data from the National Climatic Data Center (NCDC). This was 1.0°F above the 1981-2010 normal of 55.4°F (Figure 1) and was the 11th warmest year in Delaware since 1895.

Monthly temperatures varied greatly throughout the year (Figure 2). The first three months of 2015 saw much below normal temperatures, including the 6th coldest February since 1895. The last nine months of the year saw above normal temperatures, except for October, which was slightly below normal. Tremendous warmth ended the year with December temperatures averaging 12.4°F above the 1981-2010 mean. December 2015 was the warmest December on record, smashing the old record by 6.1°F.

Annual Precipitation

Statewide precipitation in 2015 averaged 46.37 inches, 2.04 inches above the 1981-2010 mean of 44.33 inches (Figure 3).

Monthly precipitation anomalies varied between positive and negative throughout the year, with seven months of below normal and five months of above normal precipitation (Figure 4). June saw the largest precipitation anomaly of 5.30 inches above the 30-year normal, helping to push the annual value above the long-term mean.

Statewide Spatial Averages

According to data from the Delaware Environmental Observing System (DEOS; deos.udel.edu), mean annual temperature anomalies varied across Delaware (Figure 5). Northern New Castle County, much of Sussex County, southern Kent County and Chester County, PA all experienced above normal temperatures for the year. Coastal Sussex County and western portions of News Castle and Kent counties saw below normal mean annual temperatures.

Precipitation across the region varied substantially in 2015, ranging from just under 40 inches to greater than 50 inches at several locations across the State (Figure 6).

Images

: Figure 1. Delaware statewide annual mean temperature (°F) 1895-2015. Red line indicates 1981-2010 normal.

: Figure 2. Delaware 2015 monthly temperature anomalies.

: Figure 3. Delaware statewide annual precipitation (inches) 1895-2015. Red line indicates 1981-2010 normal.

: Figure 4. Delaware 2015 monthly precipitation anomalies.

: Figure 5. 2015 mean annual temperature departures from the 1981-2010 mean based upon DEOS station data.

: Figure 6. 2015 annual precipitation totals based upon DEOS station data.

Autumn 2014 Slightly Dry with Near Normal Temperatures Across Delaware

Posted on December 15, 2015 | by Dan Leathers

Autumn Temperatures

Figure 1. Delaware Statewide mean Autumn Temperature (°F) 1895-2014.

Preliminary data indicates that the statewide mean autumn temperature of 57.8°F was 0.2°F above the

1981-2010 normal of 57.6°F (Figure 1). The near normal autumn temperatures followed four consecutive seasons with below normal temperatures across Delaware. Temperatures

Figure 2. Delaware statewide temperature anomalies for January 2014 through November 2014.

have been quite variable across the State during the year (Figure 2), with seven of the first eleven months being below normal.

Autumn Precipitation

Near normal autumn temperatures were accompanied by slightly dry conditions across the state during the autumn season. The statewide

mean precipitation of 9.52 inches was 1.31 inches below the 1981-2010 normal of 10.83 inches (Figure 3). Monthly precipitation anomalies have varied between positive and negative during the year, but

no month has seen large departures from normal (Figure 4).

Figure 4. Delaware statewide precipitation anomalies for January 2014 through November 2014.

Statewide Spatial Averages

Data from the Delaware Environmental Observing System (DEOS) show that temperatures varied considerably across the State during the autumn season (Figure 5), with generally small positive or negative departures at most stations. The largest departures were found along the coastal areas of Sussex County where cool conditions were dominant.

Precipitation varied from as low as 7.51 inches along the Atlantic Coast to a high of 14.52 inches in western Chester County, PA. Even with this large variation, most stations in the region experienced slightly dry conditions during the season, with the greatest negative anomalies found along the Atlantic Coast and in northern Chester County, PA (Figure 6).

Figure 5. Autumn 2014 average temperature departures from the 1981-2010 mean based upon DEOS station data.

Figure 6. Autumn 2014 precipitation departures from the 1981-2010 mean based upon DEOS station data.

November 2015: Very Warm with Near Normal Precipitation Across Delaware

Posted on December 7, 2015 | by Dan Leathers

Posted on Mon 12/21/15

Figure 1. Delaware statewide mean November temperature (°F) 1895-2015. Red line indicates 1981-2010 normal.

Figure 2. Delaware statewide November precipitation (inches) 1895-2015. Red line indicates 1981-2010 normal.

November Temperatures

Preliminary data indicates that the statewide average temperature in November was 51.5°F; this was 3.9°F above the 1981-2010 normal of 47.6°F (Figure 1), making November 2015 the fourth warmest on record since 1895. This November was the warmest since 2003.

November Precipitation

Delaware’s statewide precipitation for November 2015 averaged 3.24 inches, 0.16 inches below the 1981-2010 mean (Figure 2). November 2015 saw no snowfall accumulations anywhere in the State.

Statewide Spatial Averages

Data from the Delaware Environmental Observing System (DEOS) shows that November temperatures were above normal across all of Delaware and Chester County, PA (Figure 3). Several stations in northern New Castle County, DE and Chester County, PA saw anomalies between 4° and 6°F above the 30-year normal for November.

Precipitation was below normal at the majority of locations across the State, with larger negative departures across the northern portion of the region (Figure 4).

Figure 3. November 2015 average temperature departures (°F) from the 1981-2010 mean based upon DEOS station data.

Figure 4. November 2015 precipitation departures (inches) from the 1981-2010 mean based upon DEOS station data.

Autumn 2015 Brings Warmth and Near Normal Precipitation to Delaware

Posted on September 7, 2015 | by Dan Leathers

Posted on Tue 01/05/16

Figure 1. Delaware statewide mean Autumn temperature (°F) 1895-2015. Red line indicates 1981-2010 normal.

Figure 2. Delaware statewide Autumn precipitation (inches) 1895-2015. Red line indicates 1981-2010 normal.

Autumn Temperatures

Preliminary data indicates that autumn temperatures were appreciably above the 30-year “normal” during 2015. The statewide mean autumn temperature of 59.9°F was 2.3°F above the 1981-2010 mean value of 57.6°F (Figure 1). This made autumn of 2015 the sixth warmest since records began in 1895.

Autumn Precipitation

The statewide mean precipitation of 10.30 inches was 0.53 inches below the 1981-2010 normal of 10.83 inches, and was the 3rd year in a row with below normal Autumn rainfall (Figure 2).

Statewide Spatial Averages

Data from the Delaware Environmental Observing System (DEOS) show that autumn temperatures across the entire State were above normal, except for a few stations in southern Sussex County and northern Kent County (Figure 3). Northern Delaware and Chester County, PA saw the largest positive temperature anomalies reaching greater than 3°F at several stations.

Autumn rainfall varied significantly across the State depending upon location. In general, the heaviest precipitation fell across coastal and southern Sussex County, while portions of northern Delaware and Chester County, PA saw the largest negative rainfall departures (Figure 4).

Autumn 2015 average temperature departures from the 1981-2010 mean based upon DEOS station data.

Figure 3. Autumn 2015 average temperature departures (°F) from the 1981-2010 mean based upon DEOS station data.

Figure 4. Autumn 2015 precipitation departures (inches) from the 1981-2010 mean based upon DEOS station data.

Cool Temperatures and Near Normal Precipitation Characterize Delaware’s Climate During 2014

Posted on January 7, 2015 | by Dan Leathers

Posted on Mon 01/26/15 , Updated 02/01/16

Figure 1. Delaware statewide annual mean temperature (°F) 1895-2014.

Figure 2. Delaware monthly temperature anomalies.

Annual Temperatures

Statewide mean annual temperature in 2014 was 54.8°F according to preliminary data from the National Climatic Data Center (NCDC). This was 0.6°F below the 1981-2010 normal of 55.4°F (Figure 1) and was the coolest year in Delaware since 2003.

Monthly temperatures varied greatly throughout the year (Figure 2). The first four months of 2014 saw much below normal temperatures accompanied by heavy snowfall across the State. Although late spring and early summer saw a return to above normal temperatures, the late summer climate was cooler than normal, a welcome respite from the summer heat for many residents. The year ended with a return to warmth in three of the last four months.

Annual Precipitation

Statewide precipitation in 2014 averaged 43.49 inches, 0.84 inches below the 1981-2010 mean of 44.33 inches (Figure 3).

Monthly precipitation anomalies varied between positive and negative throughout the year, with six months of above normal and six months of below normal precipitation (Figure 4). None of the monthly precipitation anomalies were large, leading to the near normal annual total.

Statewide Spatial Averages

According to data from the Delaware Environmental Observing System (DEOS; deos.udel.edu), mean annual temperatures were below normal across the entire State with the largest negative anomalies found in coastal Sussex County (Figure 5).

Precipitation across the region varied substantially in 2014, ranging from just under 39 inches to greater than 50 inches across the region (Figure 6).

Figure 3. Delaware statewide annual precipitation (inches) 1895-2014.

Figure 4. Delaware monthly precipitation anomalies.

Figure 5. 2014 mean annual temperature departures from the 1981-2010 mean based upon DEOS station data.

Figure 6. 2014 annual precipitation totals based upon DEOS station data.

Cool Temperatures and Near Normal Precipitation Characterize Delaware’s Climate during November 2014

Posted on December 7, 2014 | by Dan Leathers

During November 2104 Delaware’s climate was cool with near normal precipitation.

November Temperatures

Preliminary data indicates that the statewide average temperature in November was 44.7°F, 2.9°F below the 1981-2010 normal of 47.6°F (Figure 1) and the third November in a row with below normal temperatures.

November Precipitation

Delaware’s preliminary statewide precipitation total for November 2014 averaged 3.74 inches, 0.34 inches above the 1981-2010 mean (Figure 2). The first snowfall of the season occurred on November 26th with accumulations observed from extreme northern Delaware into Chester County PA (Figure 3).

Statewide Spatial Averages

All stations across the Delaware Environmental Observing System (DEOS) network experienced lower than normal temperatures during November (Figure 4). Temperature anomalies of greater than -5.0°F were common across much of southern Delaware with smaller negative anomalies found across northern Delaware and Chester County, PA.

Precipitation was homogeneously distributed across the region ranging from over 5 inches in northern Kent County to less than three inches along the Atlantic Coast (Figure 5).

Images

: Figure 1. Delaware statewide mean Nov temperature (°F) 1895-2014.

: Figure 2. Delaware statewide mean Nov precipitation (inches) 1895-2014.

: Figure 3. Snowfall accumulations during the November 26th event. Values based upon DEOS station data.

: Figure 4. Nov 2014 average temperature departures from the 1981-2010 mean based upon DEOS station data.

: Figure 5. Nov 2014 total precipitation based upon DEOS station data.

Record Cold Invades Delaware

Posted on November 19, 2014 | by Dan Leathers

Figure 1. Minimum temperatures for DEOS stations throughout Delaware for November 19, 2014.

Temperatures around the First State were more like January than November this morning. In fact, several official National Weather Service observing stations reported record low temperatures:

Wilmington New Castle County Airport: 19 degrees (Previous record: 22 in 1997)
Dover Air Force Base: 21 degrees (Previous record: 24 in 1959)
Georgetown Sussex County Airport: 19 degrees (Previous record: 24 in 2005)

Typical low temperatures for November 19th range from 36 to 38 degrees across Delaware, but today’s temperatures were nearly 20 degrees below normal in some parts of the state. Around the Delaware Environmental Observing System network, temperatures were in some cases even lower. Below is a list of stations that saw low temperatures dip below 20 degrees this morning:

Station	Low Temperature
Stockley	16.6
Georgetown	16.8
Hockessin	17.2
Mt. Cuba	17.3
Harrington	17.4
Newark	17.5
Lewes	17.7
Milford	17.7
New Castle	18.6
Jones Crossroads	18.6
Greenville	18.6
Woodside	18.7
Laurel	18.9
Prices Corner	19.0
Wilmington	19.1
Harbeson	19.3
Newark	19.3
Claymont	19.4
Selbyville	19.7
Glasgow	19.7
Smyrna	19.7

The current cold weather pattern we are in is unusual, but not unprecedented. The lowest recorded temperatures in Delaware on this date occurred in 1936 at several locations up and down the state, with Wilmington Porter Reservoir coming in the lowest at 15 degrees on November 19, 1936. Temperatures are expected to remain unseasonably cold for the remainder of the week, with signs of a milder weather pattern coming early next week.

2013 Warm and Wet Across Delaware

Posted on January 7, 2014 | by Dan Leathers

Delaware’s 2013 climate was characterized by slightly warmer than normal temperatures and above normal precipitation values.

Annual Temperature

Statewide mean annual temperature in 2013 was 56.5°F according to preliminary data from the National Climatic Data Center (NCDC). This was 0.7°F above the 1981-2010 normal of 55.8°F (Figure 1) and was the fourth year in a row with above normal temperatures. However, this year was nearly 2.0°F cooler than 2012’s all time high value of 58.4°F.

Annual Precipitation

Statewide precipitation in 2013 averaged 49.93 inches, 4.07 inches above the 1981-2010 mean of 45.86 inches (Figure 2). Most areas of the state saw substantially above normal precipitation during the summer months, making the summer of 2013 the 5th wettest on record since 1895.

Statewide Spatial Averages

According to data from the Delaware Environmental Observing System (DEOS; deos.udel.edu), mean annual temperatures were above normal across portions of New Castle, western Kent and Sussex counties, and across Chester County, PA (Figure 3). Mean annual temperatures were below normal across the remainder of the State.

Precipitation was much above normal in all locations except southwestern Kent County and portions of Chester County, PA (Figure 4). The largest positive precipitation departures were found along the eastern portions of Sussex County where some locations received 10 inches more precipitation than normal.

Images

: Figure 1. Delaware statewide mean annual temperature (°F) 1895-2013.

: Figure 2. Delaware statewide mean annual precipitation (inches) 1895-2013.

: Figure 3. 2013 mean annual temperature departures from the 1981-2010 mean based upon DEOS station data.

: Figure 4. 2013 annual precipitation departures from the 1981-2010 mean based upon DEOS station data.

Cool and Dry Conditions Characterize Delaware Climate During November 2013

Posted on December 7, 2013 | by Dan Leathers

Figure 1. Delaware statewide mean November temperature (°F) 1895-2013.

Figure 2. Delaware statewide November precipitation (inches) 1895-2013.

November Temperatures

Statewide average temperature in November was 46.5°F according to preliminary data from the National Climatic Data Center (NCDC). This was 1.5°F below the 1981-2010 normal of 48.0°F (Figure 1) and was the fourth month this year with below normal temperatures.

November Precipitation

Statewide precipitation in November averaged 2.65 inches, 0.90 inches below the 1981-2010 mean of 3.55 inches (Figure 2). Much of this month’s precipitation fell on the 27th in association with a strong coastal storm.

Statewide Spatial Averages

Mean monthly temperatures were well below normal across the entire DEOS (deos.udel.edu) network in November, with the largest departures found in southern and coastal Sussex County (Figure 3). Maximum temperatures were uniformly below normal across the entire State (Figure 4), while average minimum temperatures were below normal at all locations except portions of Chester County, PA where they were near normal (Figure 5).

Precipitation was below normal throughout the State, except for stations in the northeastern portion of New Castle County (Figure 6). The largest negative precipitation anomalies were found across inland, southern Delaware and across portions of Chester County, PA.

Figure 3. November 2013 average temperature departures from the 1981-2010 mean based upon DEOS station data.

Delaware November 2013 maximum temperature departures from the 1981-2010 mean based upon DEOS station data

Figure 4. November 2013 maximum temperature departures from the 1981-2010 mean based upon DEOS station data

Delaware November 2013 minimum temperature departures from the 1981-2010 mean based upon DEOS station data

Figure 5. November 2013 minimum temperature departures from the 1981-2010 mean based upon DEOS station data

Delaware November 2013 precipitation departures from the 1981-2010 mean based upon DEOS station data

Figure 6. November 2013 precipitation departures from the 1981-2010 mean based upon DEOS station data

2012 is Warmest Year on Record for Delaware Since 1895

Posted on January 7, 2013 | by Dan Leathers

Posted on Sat 02/23/13 , Updated 04/05/13

Statewide Mean Annual Temperature 1895-2012

Figure 1. Delaware statewide mean annual temperature (°F) 1895-2012.

Preliminary data indicates that Delaware saw its warmest year on record during 2012.

The mean annual temperature of 58.8 ° F was 3.9 ° F above the 1895 – 2012 mean temperature, making it the warmest year since records began in 1895.

This year broke the previous record of 58.1 ° F set in 2011.

The six warmest years on record have all occurred since 1990 (Figure 1).

The warm temperatures were accompanied by very dry conditions across the state during the year. The statewide mean precipitation of 34.53” was 10.05” below the 1895-2012 statewide mean, making 2012 the 6^th driest year since records began in 1895 (Figure 2).

Conditions in Delaware mirrored those across much of the United States.

The contiguous 48 states had their highest temperature and 15th driest year since 1895 (Figures 3 and 4).

Statewide Annual Precipitation 1895-2012

Figure 2. Delaware statewide mean precipitation (inches) 1895-2012.

Figure 3. Temperature anomalies (°F) across the contiguous United States. Map provided by the National Climatic Data Center.

Figure 4. Precipitation anomalies (inches) across the contiguous United States. Map provided by the National Climatic Data Center.