It’s Official — The Heat Is On!
Tuesday marked the first official heatwave of 2026. The earliest one since 2017 at Greg’s Weather Center in South Plainfield, NJ.
The First Heatwave of 2026 at Greg’s Weather Center Is Earliest Since 2017
SOUTH PLAINFIELD, NJ – By lunchtime, the news became official. With the thermometer reaching 92°, the third consecutive day of 90-degree weather was in the books at Greg’s Weather Center in South Plainfield, NJ. It’s official — The Heat Is On at GWC! On Monday, the high temperature reached 95°, marking the warmest day in May in at least four years in Northwestern Middlesex County. The first heatwave of 2026 is the earliest since 2017.
On Monday, the National Weather Service in Mount Holly, New Jersey, issued heat advisories, the earliest such alerts have been issued since 2006. Since GWC implemented its new Davis Weatherlink Console in April 2023, there have been 70 days with high temperatures of 90° or higher. Twelve of those days have had high temperatures of 95° or higher. Monday was the earliest of those twelve days. Records were matched or broken all across the Mid-Atlantic on Monday.
| Location | Monday’s High | Previous Record | Year |
| Philadelphia, PA | 96 | 94 | 1962 |
| Reading, PA | 96 | 96 | 1962 |
| Georgetown, DE | 96 | 91 | 1974 |
| Mount Pocono, PA | 88 | 87 | 1962 |
Another Scorcher in Store for Wednesday
The forecast from the NWS indicates that the high temperature on Tuesday could climb into the upper 90s to near 100° in Northwestern New Jersey. The mercury will reach the mid-90s again on Wednesday afternoon before a cold front moves in with strong to severe thunderstorms accompanying it. Behind the front, temperatures will be much cooler. Thursday’s high will likely be only in the low 70s, while Friday’s high will be even cooler in the mid-60s.
This early heatwave is the latest instance of the warmer than normal spring that has taken place across the Garden State in 2026. It also marks the second straight spring with relatively warmer and drier conditions than usual. At this time a year ago, there were nine days with high temperatures of at least 80°, but none of them were 90° or higher. As of today, there have been 12 days with high temperatures of at least 80°. Five of those days have had high temperatures of at least 90° with one reaching 95.
The First Heatwaves at Greg’s Weather Center
| Year | Duration | Dates |
| 2003 | 8 Days | June 23-30 |
| 2004 | 4 Days | May 22-25 |
| 2005 | 3 Days | May 27-29 |
| 2006 | 3 Days | July 16-18 |
| 2007 | 3 Days | July 8-10 |
| 2008 | 4 Days | June 7-10 |
| 2009 | 4 Days | August 16-19 |
| 2010 | 6 Days | July 4-9 |
| 2011 | 3 Days | May 27-29 |
| 2012 | 3 Days | June 20-22 |
| 2013 | 5 Days | May 29-June 2 |
| 2014 | 3 Days | July 1-3 |
| 2015 | 4 Days | July 19-22 |
| 2016 | 4 Days | July 5-8 |
| 2017 | 3 Days | May 17-19 |
| 2018 | 8 Days | June 28-July 5 |
| 2019 | 3 Days | June 26-28 |
| 2020 | 4 Days | July 19-22 |
| 2021 | 5 Days | June 5-9 |
| 2022 | 3 Days | May 21-23 |
| 2023 | 5 Days | September 4-8 |
| 2024 | 9 Days | June 18-26 |
| 2025 | 3 Days | June 23-25 |
| 2026 | 3 Days | May 17-19 |
Tied for Earliest Heatwave on Record at GWC
There is usually at least one heat wave per year in Northwestern Middlesex County. Since the installation of the first weather station at Greg’s Weather Center in May 2002, there have been several heatwaves during May, but this one is tied for the earliest on record. The longest was two years ago, from June 18th to June 26, a period of nine days. The first heatwaves of 2003 and 2018 were also over a week, as well as eight days. This latest torrid stretch will subside on Wednesday.
There appears to have been a pattern shift in the wake of the severe drought from August to November 2024. The last couple of years have been drier, with warmer weather happening earlier. In addition, an El Niño is in the process of developing in the Pacific. Indications are that this particular El Niño episode may be one of the strongest, if not the strongest, on record. The last major El Niño event was in 1997. The strongest one to occur was in 1877. The one in 1982-83 was the most significant of the modern era.