Unusually dry, warm and windy weather helped trigger a rash of wildfires across the region Monday, causing traffic and transit problems, consuming hundreds of acres of forest in South Jersey and forcing evacuations on Long Island.

While April is considered the start of wildfire season, the unusually dry conditions have generated a large number of fire warnings across the Eastern Seaboard, and the threat could continue into spring, weather experts said.

The widespread blazes are more typical of the wildfires that break out in the grasslands of the Midwest and Great Plains this time of year, said Mark Svoboda, a climatologist at the National Drought Mitigation Center at the University of Nebraska-Lincoln.

"This is very unusual for this time of year over such a large portion of the East Coast," Mr. Svoboda said.

High wind gusts of between 30 and 42 miles per hours Monday made the fires particularly hard to control, New Jersey and New York officials said.