Autumn's Early Grip: New Hampshire Prepares for a Significant Mid-Week Weather Shift

As we step further into September, New Hampshire is gearing up for a significant meteorological shift, signaling an early but undeniable taste of autumn. While Monday offered a pleasant respite with comfortable temperatures, the coming days promise a dramatic change, ushering in a cooler, wetter pattern.

Today, Tuesday, September 16, 2025, marks the beginning of this transition.

Expect to see increasing cloud cover throughout the morning, gradually thickening as a system approaches. By the afternoon, scattered showers are likely to develop across much of the state, with the North Country facing potentially more persistent rainfall. Temperatures will take a noticeable dip, struggling to climb much beyond the low 60s in many areas.

The chill deepens considerably into Wednesday.

Don't be surprised to find yourself reaching for a heavier jacket as temperatures across the Granite State will remain stubbornly in the 50s, or even lower in higher elevations. Expect more widespread, albeit lighter, showers, particularly during the morning hours. The air will feel distinctly crisper, truly announcing autumn's arrival.

Looking ahead to Thursday and Friday, the skies are expected to clear, offering a return to sunshine.

However, the cold air mass will linger, ensuring brisk days and even colder nights. Residents in higher terrain and more rural areas should be mindful of the potential for frost advisories overnight as temperatures could drop significantly after sunset. Daytime highs will hover in the upper 50s, feeling much cooler than earlier in the week.

As the weekend approaches, there's a glimmer of hope for a gradual warming trend.

Mostly sunny conditions are anticipated to prevail, with temperatures slowly creeping back into a more comfortable range, though still feeling definitively autumnal. Be sure to dress in layers and keep an umbrella handy for the mid-week. This week's forecast is a clear reminder that while summer's warmth was lovely, New Hampshire's signature crisp autumn air is officially moving in.