The summer tide came rolling in this year much warmer than 2024. In fact, the ocean temperatures were tropical enough to be among the warmest on record at the Jersey Shore.
From June to September, peak beach season, the ocean water temps, measured at Atlantic City’s Steel Pier, averaged 71.4 degrees – tied with 1951 for the fifth warmest season since recordkeeping began in 1912.
The National Oceanic and Atmospheric Administration oversees this data. Jim Eberwine, my weather dad and longtime NOAA meteorologist, collected the daily data, who then passed it along to me.
This was exactly five degrees warmer than last year’s 66.4 degrees. Remember last year? The water was cold. You sweated on the sand but shivered in the ocean. June and July had zero days with a water temperature above 75 degrees in Atlantic City. In fact, 11 July days were in the very chilly 50s; 55 degrees was the 8 a.m. water temperature on July 18, 2024.
The old saying, “life’s at ease with an ocean breeze” is true. Wind direction all summer, and during Local’s Summer in September, played a critical role in this top five ranking.
There are three main factors that drive water temperatures.
The Sun: In spring and summer, the sun is higher in the sky, so it warms up the ocean water faster. In fall and winter, the sun is lower, so the water stays cooler.
The Currents: In New Jersey, there is a warm ocean current called the Gulf Stream. It starts near Florida and flows all the way to Europe. It does not always reach New Jersey, but sometimes does when it swirls, bringing warmer water to the shore.
Wind Direction: Winds that blow from the east, called onshore winds, push warmer ocean water toward the beach. But winds from the south or southwest bring colder water. When winds blow along the shore, they can cause something called Ekman Pumping. This pushes warm surface water away and pulls colder water up from the bottom of the ocean to where we swim.
While the sun and currents are constant, the wind direction varies day by day, month to month and, for purposes of this column, year by year.
This year, onshore winds blew 30% of the time between June and August at Atlantic City International Airport in Egg Harbor Township, our NOAA weather station with wind direction measurements closest to Atlantic City. The average is 15% of the time. In other words, we had twice the onshore winds as usual. September was the same, with onshore winds roughly 38% of the time in 2025. The average is 27%.
Those extra onshore winds pushed in warmer water from the Gulf Stream, and limited the amount of colder upwelling. It also led to an August that was cooler than average on land, and just about average during September, according to New Jersey State Climatologist Dave Robinson, my other weather dad.
The average June-to-September water temperature is 68.6 degrees. June was the only month below average at 65.8 degrees. That is not a surprise. However, July (72.9 degrees), August (74.8 degrees), September (72.1 degrees) were all above average.
If you had to compare it, the sea surface temperatures you experienced this season were more like an average season for Virginia Beach. Aug. 16 and 17 were the warmest water days, staying above 80 degrees. June 1 had the coldest water, staying below 60 degrees. No surprise there, as the sun is trying to heat up the water.
Joe Martucci, a Certified Broadcast Meteorologist and Digital Meteorologist, is the President and Director of Meteorology for Cup A Joe Weather and Drone. You can connect with him at cupajoe.live.
