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2019 Weather In Review: Upper Delaware Scenic and Recreational River

View of the Delaware River under a blue sky with puffy white clouds.
Photo by Nicholas A. Tonelli (CC by 2.0)

In order to better understand ecosystem health in national parks, the Eastern Rivers and Mountains Network measures ecosystem "vital signs" in select national parks in West Virginia, Pennsylvania, New Jersey, and New York. One of those vital signs is weather and climate. Below is a summary of 2019 weather conditions at Upper Delaware Scenic and Recreational River.

In all, 2019 was wetter and warmer than normal. The year ended as the 21st wettest and 24th warmest since 1895. Weather data collected from surrounding areas from 1895–2019 show increasing trends in annual average temperature (+0.21 °F per decade) and annual total precipitation (+0.48 inches per decade).

Information in this brief represents county-scale weather data averaged from all of the counties surrounding the park. These counties include Pike and Wayne counties, Pennsylvania, and Delaware, Orange, and Sullivan counties, New York. Individual weather station data may vary from what is reported here. Data are available from the National Climate Data Center.

Temperature

In total, 2019 was the 24th warmest year at the park since 1895. Spring and summer were particularly warm (Figure 1). Nine months had higher than normal temperatures, with February, April, and July all being more than 3 °F above normal (Table 1).

Figure 1. Average temperature rankings for counties surrounding the park. The figure shows that the summer was "much above normal," the spring was "above normal," and that autumn and winter were "near normal." In total, the year was "above normal."
Figure 1. Seasonal and annual temperature rankings for counties surrounding the park. An arrow at the top of the figure would represent the warmest year/season on record (since 1895); at the bottom, the coldest year/season on record.
Month/Year Average temperature (°F) Departure from
long-term average (°F)
January 23.1 +0.8
February 26.9 +3.5
March 31.7 -1.0
April 47.7 +3.2
May 56.5 +1.0
June 63.8 0.0
July 71.7 +3.2
August 67.5 +0.9
September 61.8 +2.2
October 51.5 +2.7
November 34.5 -3.2
December 28.3 +1.6
2019 47.1 +1.2

Table 1. Monthly and annual average temperature and departure from long-term averages. Departures from average show how different 2019 was compared to relevant averages from 1895-2018.

Precipitation

In total, 2019 was the 21st wettest year in the park since 1895, and most seasons were wetter than normal (Figure 2). In contrast, the summer was very dry. By the end of the year, the area received 50.9 inches of precipitation — 6.3 inches more than the long-term average (Table 2).

Figure 2. Average precipitation ranking for counties surrounding the park. The figure shows that the spring and autumn had total precipitation that was "much above normal." The winter had "above normal" and the summer had "below normal" precipitation.
Figure 2. Seasonal and annual precipitation rankings for counties surrounding the park. An arrow at the top of the figure would represent the wettest year/season on record (since 1895); at the bottom, the driest year/season on record.
Month/Year Total precipitation (in.) Departure from
long-term average (in.)
January 5.4 +2.3
February 2.7 -0.2
March 2.5 -0.9
April 5.6 +1.9
May 6.3 +2.3
June 5.0 +0.7
July 4.3 0.0
August 3.7 -0.5
September 1.5 -2.5
October 6.7 +3.0
November 3.3 -0.2
December 3.9 +0.4
2018 50.9 +6.3
Table 2. Monthly and annual total precipitation and departure from long-term averages. Departures from average show how different 2019 was compared to relevant averages from 1895-2018.

Temperature and Precipitation Trends
(1895-2019)


Data from 1895–2019 for counties surrounding the park show increasing trends in annual average temperature (+0.21 °F per decade) and annual total precipitation (+0.48 inches per decade; Figure 3).
Figure 3. Line graph of annual average temperature (°F) and annual total precipitation (in.) for counties surrounding the park from 1895–2019 shows increasing trends for both parameters.
Figure 3. Annual average temperature (°F) and annual total precipitation (in.) for counties surrounding the park from 1895–2019. Dashed lines represent linear trends.

Climate Change

Today's rapid climate change challenges national parks in ways we've never seen before. Wildlife migrations are altered, increasingly destructive storms threaten cultural resources and park facilities, habitat is disrupted—the list goes on. Click here to discover how climate change is affecting our nation's treasures, what the National Park Service is doing about it, and how you can help.

For more information, contact Mid-Atlantic Network Biologist, Jeb Wofford or Eastern Rivers and Mountains Network Program Manager, Matt Marshall.

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Upper Delaware Scenic & Recreational River

Last updated: March 2, 2020