Heat Islands: Cities Heat Quickly, Cool Slowly

By THE ASSOCIATED PRESS

Published: July 7, 2010

NEW YORK (AP) — The high temperatures blanketing the Northeast and mid-Atlantic regions of the country are making many people miserable. But those in New York City, Philadelphia and other dense, built-up areas are getting hit with the heat in a way their counterparts in less developed places aren’t.

It’s called the heat island effect.

Cities absorb more solar energy during the day and are slower to release it after the sun sets. That makes for uncomfortable nights and no real relief from the heat.

Because the cities haven’t cooled down as much overnight, mornings are warmer and the thermometer goes right back up when the sun starts shining again.

Geography professor William Solecki says not getting that nighttime relief can make the high temperatures even more difficult for people to take.