Edition: U.S. / Global

New York City Weather: A Century-Long Warming Trend

Published: January 9, 2000

Over the century just departed, the earth became warmer, with the average global surface temperature rising by about one degree Fahrenheit. The world is five to nine degrees warmer now than during the depth of the last ice age 18,000 to 20,000 years ago.

Over the century just entered, the warming is expected to continue. If emissions of heat-trapping gases like carbon dioxide - products of the burning of fossil fuels like coal and oil - are not reduced, many experts believe, the surface temperature of the earth will rise at a pace equal to its rise in the last quarter century. And that rate was more than triple the century-long average, government scientists say.

Global warming is believed to affect extremes of weather, making both heavy rainfall and drought more prevalent. But global warming expresses itself differently in different parts of the world. For instance, in the northern hemisphere, the warming has been greater the farther north one goes. And these large forces combine with natural climatic influences to produce different patterns at the local and regional levels.

Here is the way these factors played out for New York City.


Chart lists several meteorological statistics for New York City, comparing the climate of 1999 to that of the past 100 years. (Sources: National Weather Service; Pennsylvania State University.)