New Hampshire's Early Autumn Outlook: Your Guide to September 1st, 2025 Weather

Welcome to your detailed weather update for New Hampshire on September 1st, 2025! As we step into the fresh embrace of early autumn, residents across the Granite State can look forward to a blend of lingering summer warmth and the crisp hints of the season to come. Our WMUR meteorologists have the full breakdown to help you plan your day and the week ahead.

For Monday, September 1st, 2025, expect generally pleasant conditions across New Hampshire.

Most areas will see a mix of sun and clouds throughout the day, with periods of bright sunshine dominating the forecast. Temperatures will be quite comfortable, with daytime highs reaching into the mid-70s for southern and central regions, while northern New Hampshire will experience slightly cooler, yet still mild, temperatures hovering in the low 70s.

Humidity levels will remain on the lower side, making for a very enjoyable day outdoors.

A gentle breeze from the northwest, around 5 to 10 mph, will add a refreshing touch to the air, particularly in exposed areas. There's a minimal chance of any significant precipitation today, so feel free to leave the umbrella at home if you're heading out to enjoy the last vestiges of summer activities or beginning your fall adventures.

As evening approaches, temperatures will steadily drop, leading to a cool and comfortable night.

Overnight lows are expected to settle into the low to mid-50s across much of the state, with some valleys and higher elevations potentially dipping into the upper 40s. This makes for ideal sleeping weather and a perfect opportunity to open the windows and enjoy the fresh autumn air.

Looking ahead into the first week of September, the forecast appears to hold steady with generally fair weather.

We anticipate mostly dry conditions with a continued mix of sun and clouds. Temperatures are expected to hover around seasonal averages, providing a delightful transition period before the deeper chill of fall sets in. Stay tuned to WMUR for daily updates and any shifts in this evolving early autumn weather pattern!