‘September gloom’ and autumn chill takes over NJ this week, watching potential coastal storm

The Bottom Line

The theme of this week: “September gloom,” as we are now in a stretch of cloudy and unseasonably cool weather. Plus, each day this week has a rain chance in the forecast, thanks to a stalled frontal boundary just south of New Jersey. Having said that, Monday should offer a temporary break in the wet weather, as we dry out a bit with a few peeks of sun possible through the middle of the day. However, spotty showers return late, with a much wetter day on deck for Tuesday. Plus, temperatures will struggle to reach 70 degrees for the duration, making for a cool end to summer and beginning of fall. The Autumnal Equinox arrives Tuesday at 8:04 p.m. Wednesday and Thursday will remain mostly cloudy, with a few showers around and highs only in the 60s. And then our attention will turn to a coastal storm system expected to develop off our shoreline — a nor’easter — that could bring additional rain, wind, and surf impacts to New Jersey late this week into the weekend. However, exact timing and intensity of those impacts are still very much up in the air and something we will be watching closely as the week goes on.

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Weather Hazards

For the time being, there are no major alarm bells to ring. As rain returns late Monday into Tuesday, some pockets of heavy stuff are possible. But in general, we are just looking at run-of-the-mill rainy weather for most of this week.

The late-week nor’easter could pump out some stronger winds, especially along the eastern edges of the state. And that could lead to some coastal impacts, including tidal flooding and big waves. I am not overly concerned about flash flooding from heavy rain or severe weather from thunderstorms from this storm system at this time. But the overall forecast for late this week into early next week remains highly uncertain and volatile.

Climatological Context

September 21 is the 264th day of 2026.

Normal high temperatures range from 75 to 77 degrees, while normal low temperatures range from 56 to 59 degrees.

September is, on average, New Jersey’s fourth warmest and sixth driest month of the year.

Monday

The overall theme of this week is gloomy, unsettled weather. Each day contains a rain chance in the forecast. But Monday offers a bit of a break from wet weather.

Temperatures are in the 60s across New Jersey early Monday morning. Parts of the state picked up almost 2 inches of rain Sunday, making for a soggy finish to the final weekend of summer. Road conditions are still wet and soggy, although very little is actually falling from the sky anymore.

Monday will be a little better and a little brighter, and most of the daytime hours should stay dry.

Still, with a stalled frontal boundary sitting just to our south, expect clouds to dominate with just a few peeks of sunshine breaking through around midday.

High temperatures will only rise a few degrees, maxing out near 70 degrees. The small diurnal temperature range is one effect of stagnant, cloudy, damp weather — thermometers simply do not budge very far.

Spotty showers will probably return around Monday late afternoon, continuing into the evening. Rain may become steadier and heavier overnight. Low temperatures are forecast to dip into the upper 50s.

Tuesday

The Autumnal Equinox, officially arriving at 8:04 p.m. And the change of seasons will likely be a wet one, as Tuesday will be the wettest day of the next several.

Expect periods of rain through much of the day, with cloudy skies and unseasonably cool temperatures. It will not rain all day though, so not necessarily a wash out. High temperatures will only reach the middle 60s.

There is no need to ring major flooding alarm bells here, although pockets of heavier rain are possible. Just put those umbrellas up and flip on those windshield wipers.

Farewell summer. See you next year.

Wednesday

Wednesday remains unsettled, but not as wet as Tuesday.

Just a few showers will be possible. Otherwise, expect mostly cloudy skies, breezy conditions, and highs stuck in the mid 60s.

That is well below normal for late September and definitely has an October-ish flavor. I am confident you will find some dry breaks between showers, but sunshine will be limited.

Thursday & Beyond

Thursday keeps the damp and dreary weather going.

Expect cloudy skies, highs again in the mid 60s, and the chance of coastal showers.

And then our attention will increasingly turn offshore, where a coastal storm system is expected to begin organizing near the U.S. East Coast.

Yes, you can call it a nor’easter. (While the definition fits, I prefer to go with the more generic "coastal storm" in this case, as "nor'easter" carries a connotation of snow — which is not true, and also not the case.)

The consensus forecast suggests a deepening area of low pressure over the ocean may come close enough to New Jersey to bring some impacts our way. I am talking about a combination of rain, wind, rough surf, and coastal flooding. Timing would be roughly Friday through the weekend.

But there is still a lot we do not know regarding the exact track, timing, strength, and how close the storm ultimately gets.

At this point, wind and coastal impacts are more concerning to me than heavy rain. (Worst case scenario: A period of 60 mph wind gusts?) Big waves and tidal flooding could become issues along the Shore regardless of the storm’s precise path.

So this is one to watch, not one to panic about just yet. Let's see how things continue to develop.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook for the latest forecast and realtime weather updates.