Upper Delaware in 2020: a very warm year with near-normal precipitation

The National Park Service's Eastern Rivers and Mountains Network measures ecosystem "vital signs" in selected national parks in West Virginia, Pennsylvania, New Jersey and New York. Weather and climate is one of them. This is the network's summary of 2020 at Upper Delaware Scenic and Recreational River.

Weather versus climate

Weather is the short-term change in the atmosphere, over minutes to months: what is happening outside right now. Climate is what to expect from long-term patterns over 30 years or more. The brief's shorthand: climate is what you expect, a hot summer, and weather is what you get, a warm rainy day. So the question for 2020 is how it compared with a "normal" year.

Where the numbers come from

The figures are county-scale averages over the counties around the park, for the period of record from 1895 to 2020: Pike and Wayne counties in Pennsylvania, and Delaware, Orange and Sullivan counties in New York. Individual weather stations may differ. The data come from NOAA's National Climate Data Center.

2020 month by month

The brief calls 2020 very warm, with near-normal precipitation: the third warmest year on record for the area, and the 60th wettest. Ten months ran warmer than the long-term average, led by January, February and March. April and May were cooler than average.

Departures compare 2020 with the long-term averages for 1895 to 2019. August was the wettest month relative to its average. For the year, 44.4 inches of precipitation fell, just 0.2 inch less than the long-term average.

A century of change

For the counties around the park, annual average temperature has risen by about 0.22 °F per decade since 1895, and annual total precipitation by about 0.46 inch per decade.

Annual average temperature and annual total precipitation for the counties around the park, 1895 to 2020; dashed lines show linear estimates of change. Figure from the National Park Service's page.

Looking ahead, National Park Service scientists have used models to estimate that by 2100 the park's annual average temperature will rise by 3.2 to 9.5 °F, from the best-case to the worst-case scenario, and that annual total precipitation will rise by 7 to 14 percent, as reported by Gonzalez and others in 2018.

Sources

• National Park Service, Eastern Rivers and Mountains Network, "2020 Weather In Review: Upper Delaware Scenic and Recreational River" (https://www.nps.gov/articles/000/2020-weather-in-review-upper-delaware-scenic-and-recreational-river.htm); the sky photograph and the two seasonal ranking charts are left out; rewritten in hubnx's own words.