September weather forecast
New Hampshire, USA

September in New Hampshire brings the arrival of autumn, with a noticeable decrease in temperatures and the beginning of the spectacular fall foliage for which the region is famous. The average lows for the state are from 47°F (8.3°C) to 54°F (12.2°C), and the average highs range from 66°F (18.9°C) to 74°F (23.3°C). This cooling trend signals the transition from the hot summer months to the more temperate and varied weather of fall.

Rainfall in September is relatively even, and the chance of thunderstorms diminishes as the month progresses. The coastal influence of the Atlantic Ocean continues to affect the southeastern part of the state, while the northern mountain ranges begin to exert more influence on the weather, especially in the northern regions.

Outdoor activities remain popular, but the focus shifts from beaches to the trails, mountains, and scenic drives that showcase the changing leaves. The early fall foliage draws visitors seeking to experience the natural beauty of New Hampshire's forests.

September serves as a bridge between the consistent warmth of summer and the cooler, more variable weather of autumn. It offers a blend of the last warm days of summer and the first cool nights of fall, with temperatures dropping noticeably, especially towards the end of the month.

Compared to August, September in New Hampshire brings a significant change in the weather, marked by cooler temperatures and the onset of the fall season. The shift is evident in the changing colors of the leaves, the decrease in humidity, and the gradual preparation for the colder months ahead.

---

• Manchester - September »
  In Manchester in September, during 8.4 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. On the first day of September in Manchester, sunrise is at 6:11 am and sunset at 7:20 pm.
• Nashua - September »
  The autumn equinox in September signals the commencement of fall in Nashua, reflected by a considerable drop in the daytime temperature to 72.5°F (22.5°C) and the temperature at night to 53.8°F (12.1°C). In Nashua, snow does not fall in June through September.
• Concord - September »
  In Concord in September, it is raining for 10.7 days, with typically 1.65" (42mm) of accumulated precipitation. In Concord, New Hampshire, snow does not fall in June through September.
• Derry - September »
  In Derry, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation. On the first day of September in Derry, sunrise is at 6:10 am and sunset at 7:19 pm.
• Dover - September »
  The month with the least rainfall in Dover is September, when the rain falls for 10.7 days and typically collects 1.26" (32mm) of precipitation. The month with the least rainfall in Dover is September, when the rain falls for 10.7 days and typically collects 1.26" (32mm) of precipitation.
• Rochester - September »
  In Rochester snow does not fall in June through September. In Rochester, New Hampshire, snow does not fall in June through September.
• Salem - September »
  In Salem, New Hampshire, in September, it is raining for 10.6 days, with typically 1.3" (33mm) of accumulated precipitation. An average nighttime temperature of 55.8°F (13.2°C) is recorded in Salem, New Hampshire, during September.
• Merrimack - September »
  In Merrimack, New Hampshire, in September, it is raining for 8.4 days, with typically 0.79" (20mm) of accumulated precipitation. In Merrimack, in September, during 8.4 rainfall days, 0.79" (20mm) of precipitation is typically accumulated.
• Londonderry - September »
  On the first day of September in Londonderry sunrise is at 6:10 am and sunset at 7:19 pm. In Londonderry, New Hampshire, in September, it is raining for 8.4 days, with typically 0.79" (20mm) of accumulated precipitation.
• Keene - September »
  In Keene, New Hampshire, snow does not fall in June through September. In Keene snow does not fall in June through September.
• Bedford - September »
  In Bedford in September, it is raining for 8.4 days, with typically 0.79" (20mm) of accumulated precipitation. In Bedford, in September, it is raining for 8.4 days, with typically 0.79" (20mm) of accumulated precipitation.