After Sandy, a nor'easter and a bout of slushy snow as late as last week, the Hudson Valley is starting December with unusually high temperatures in the low 60s -- about 10 degrees above average.
The forecast also calls for light rain showers into Sunday night and early Monday morning.
Hudson Valley temperatures Sunday will reach highs in the 50s and drop to the mid-40s by nightfall.
A warm front and southerly winds then will steadily raise temperatures to the low 60s by Tuesday, meteorologists said.
"We are in kind of a transition from one season to another," said Joey Picca, a meteorologist for the National Weather Service. "Because November had run so cold -- several degrees below normal in some areas -- when we do see these above-normal temperatures they seem that much more extreme."
Temperatures this time of year normally range from highs in the mid-40s to lows around the lower to mid-30s, Picca said, but he added that fluctuating temperatures aren't uncommon.
The National Weather Service had issued a dense fog advisory for the Hudson Valley and New York City areas until midday Sunday. Drivers had been warned to exercise extreme caution as visibility dropped for a time to a quarter mile or less.
After the springlike weather, temperatures are expected to drop back down mid-40s by the end of the week, forecasters said.