January 7, 2000

Long Island Weather of 1999 -
A Tie for the Third Hottest Year on Record

Upton, NY - Remember July of 1999? Long Islanders sweltered that month, with the thermometer reaching temperatures between 90 degrees F and 100 degrees F for twelve days. Yet, during two days of the month, the thermometer plummeted
to below 50 degrees F. While July stands out because of its uncomfortable extremes, temperatures were above normal in every month of 1999 except for October. In fact, 1999 tied with 1990 as the third hottest year on record. The yearly average temperature was 52.7 degrees F; only 1998 and 1991, with average yearly temperatures of 53.1 degrees F and 52.9 degrees F respectively, were hotter. The U.S. Department of Energy's Brookhaven National Laboratory has been keeping meteorological records since 1949.

Total yearly precipitation in 1999 was 51.7 inches, 3.4 inches more than average. Snowfall, however, was lighter than usual, with 23 inches of snow falling in the 1998-99 season, compared to an average yearly snowfall of 29.6 inches.

Brookhaven Lab meteorologist Victor Cassella said most Long Islanders were lucky in terms of weather in 1999, with no major storms causing severe damage here, despite a busy hurricane season on the Atlantic coast. While 13 hurricanes and tropical storms pounded the coastline, only one -Tropical Storm Floyd - reached Long Island. Between Sept 15 and 16, the storm dumped 3.69 inches of rain at Brookhaven Lab. Southold residents were not so lucky, with a tornado hitting the town on August 8, causing substantial damage to some homes and boats. Although Long Island is not known as tornado country, Cassella said about one or two tornadoes strike the region each year.

Five record high temperatures and two record lows were recorded in 1999. January 23 brought a record high of 59.5 degrees F, beating the previous record of 56 degrees F set in 1973. On June 7, the thermometer hit 95 degrees F, which beat the previous record of 91 degrees F set in 1984. In July, three record highs were recorded. On July 5, the thermometer soared to 100 degrees F, two degrees more than the previous high for that date in 1955. July 6 brought a high temperature of 98.5 degrees F, which was a half-degree warmer than the record high in 1986. The thermometer hit 93.5 degrees F on July 27, also a half-degree warmer than the previous record set in 1966. Truly a month of extremes in 1999, July also brought two new daily low temperatures. On July 14 and 15, temperatures of 49.5 degrees F and 49 degrees F were recorded, which beat the previous records set for those dates by 3.5 degrees F and 2 degrees F, in 1962 and 1950 respectively.

What will the weather be like in 2000? Cassella ventured a guess, saying, "I predict that we'll get a few coastal storms in late January, February, March or April, which will bring a significant amount of snow." Maybe it's time to get the snow shovels ready, because Cassella's weather predictions have been correct for the past two years.

The U.S. Department of Energy's Brookhaven National Laboratory creates and operates major facilities available to university, industrial and government personnel for basic and applied research in the physical, biomedical and environmental sciences, and in selected energy technologies. The Laboratory is operated by Brookhaven Science Associates, a not-for-profit research management company, under contract with the U.S. Department of Energy.
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NOTE TO EDITORS: Upon request, we will provide a graph of the average monthly temperatures in 1999, compared with the overall average monthly temperatures for the period 1949-99 at Brookhaven National Laboratory.

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