Forecasters say temperatures will be running 10 to 20 degrees below normal on Tuesday and Wednesday.
We're almost a full week into June, when it's supposed to be safe to toss aside jackets and break out the short-sleeve shirts.
But Mother Nature is behaving like it's April, with cloudy skies, damp days and cooler than normal temperatures lingering in New Jersey.
During the next two days, daytime highs are forecast to run about 10 to 15 degrees lower than normal across most of the state, and about 20 degrees below normal in the state's northern region.
The thermometer in Newark usually reaches 79 degrees on June 6, but on Tuesday the city's high is projected to climb no higher than 59, which is more common in early April than early June. The overnight low in Newark will be closer to 50 instead of 60, the National Weather Service says.
In Sussex, the projected high on Tuesday is only 57 degrees, which is almost 20 degrees cooler than the normal June 6 high of 76 degrees. The overnight low is forecast to drop to a chilly 46 degrees, 7 degrees cooler than normal.
Down in Atlantic City, the gap is not as big as it is in northern New Jersey, but still significant. The normal June 6 high at Atlantic City International Airport is 78 degrees, but Tuesday's forecast high is 66. The projected low is 51, which is 7 degrees cooler than the normal low of 58.
Wednesday's temperatures are expected to be similar to those on Tuesday, but are forecast to get slightly warmer on Thursday and much warmer on Friday, with bright sunshine returning for a few days.
Cooling factors
Three factors are contributing to the lower temperatures during the first part of this week, according to Jared Klein, a meteorologist at the National Weather Service's regional office in Mount Holly.
One culprit, he said, is a strong low pressure system in the upper atmosphere that is pushing cool Canadian air down over the New Jersey region. Another is the persistent cloud cover over the Garden State. And another contributing factor is a northeasterly wind that's blowing cold air from the Atlantic Ocean over the Shore and, when it's strong enough, inland areas as well.
"The ocean is still cold" this time of year, Klein said, noting it usually takes a couple of months to warm up from the heat of the summer sun. Late July to late August is usually the period with the warmest ocean temperatures along the Jersey Shore, according to federal climate data.
While many New Jerseyans might not be thrilled about this week's cool weather pattern, it's not unprecedented to get temperatures this low in early June, said New Jersey State Climatologist David Robinson at Rutgers University.
Robinson said Newark's coolest maximum temperature on June 6 was 56 degrees, back in 1894, and Sussex's temperature rose no higher than 57 degrees on June 6 in 2000.
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Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality or like him on Facebook. Find NJ.com on Facebook.