January 5, 2001

Long Island Weather of 2000 - Normal Temperature, Wet Summer


Upton, NY - Where were you during the summer of 2000? You were probably indoors more than you wanted to be if you were residing or vacationing on Long Island. With 8.37 inches of rain, July of 2000 was the second wettest month since the U.S. Department of Energy's Brookhaven National Laboratory started keeping meteorological records in 1949. The wettest July occurred in 1969, when 8.62 inches of rain soaked the area. From July 25 through August 19, 2000, only five days were rain-free. The millennium year brought 54.4 inches of precipitation - six inches more than average.

Overall, Long Island's weather was calm in 2000, with no hurricanes affecting the area. Only 14 inches of snow fell during the winter of 1999-2000, while the average yearly snowfall is 29.3 inches. This is in contrast to the 10.1 inches of snow that has already fallen this December, part of the 2000-2001 winter season.

Brookhaven Lab's meteorologist Victor Cassella predicts that the trend will continue. "The last four winters have brought us below-average snowfalls," he said. "Over the last 51 years, we've never gone five consecutive winters with below-average snowfalls, so we're due for a cold, white winter."

In predicting weather patterns for 2001, one more recent piece of weather data must be taken into account, according to Cassella. October of 2000 was a very dry month, with 0.3 inches of rain - only the third time in Brookhaven Lab's meteorological history that less than one inch of rain fell in that month.

"That fact is significant," Cassella said, "because whenever rainfall in October has been very light, snowfall in that same year has been very heavy, with 10 to 15 inches above-average snowfall. So far, this is true for the winter of 2000-2001. December had twice the normal amount of snow for the month."

Temperature extremes were not common last year. With an average yearly temperature of 50.6 degrees F, 2000 was only 0.6 degrees F above the yearly average temperature for the past 51 years. This was a dramatic change from the last two years, which were far hotter than normal. In 1999, the average yearly temperature was 52.7 degrees F, and in 1998, it was 53.1 degrees F, the hottest year on record.

Nevertheless, five record high temperatures were recorded in 2000. January 2 and 3 brought two consecutive highs of 57 degrees F and 66 degrees F. The previous consecutive highs for these dates were 56 degrees F in 1979, and 53 degrees F in 1953. Two new highs were recorded in March, as well - 67 degrees F on the 9 th, beating the record of 60 degrees F set in 1987, and 67.5 degrees F on the 24th, which was one-half degree warmer than the previous record, also set in 1987. On October 3, a high of 79 degrees F was one degree higher than the record set in 1950. 

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.