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.

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• Manchester - September »
  In Manchester, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Manchester snow does not fall in June through September.
• Nashua - September »
  The month with the least rainfall in Nashua is September, when the rain falls for 7 days and typically collects 0.28" (7mm) of precipitation. In Nashua, New Hampshire, during September, the rain falls for 7 days and regularly aggregates up to 0.28" (7mm) of precipitation.
• Concord - September »
  In Concord, New Hampshire, during September, the rain falls for 10.7 days and regularly aggregates up to 1.65" (42mm) of precipitation. In Concord snow does not fall in June through September.
• Derry - September »
  September in Derry witnesses a gentle descent in average high-temperature, descending from August's moderately hot 80.1°F (26.7°C) to a pleasant 72.1°F (22.3°C). In Derry, in September, during 8.4 rainfall days, 0.79" (20mm) of precipitation is typically accumulated.
• Dover - September »
  On the first day of September in Dover sunrise is at 6:07 am and sunset at 7:19 pm. In Dover in September, it is raining for 10.7 days, with typically 1.26" (32mm) of accumulated precipitation.
• Rochester - September »
  The month with the least rainfall in Rochester is September, when the rain falls for 11.8 days and typically collects 1.5" (38mm) of precipitation. In Rochester, in September, during 11.8 rainfall days, 1.5" (38mm) of precipitation is typically accumulated.
• Salem - September »
  The month with the least rainfall in Salem is September, when the rain falls for 10.6 days and typically collects 1.3" (33mm) of precipitation. On the first day of September in Salem, New Hampshire, sunrise is at 6:09 am and sunset at 7:20 pm.
• Merrimack - September »
  In Merrimack, New Hampshire, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Merrimack snow does not fall in June through September.
• Londonderry - September »
  In Londonderry, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Londonderry, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation.
• Keene - September »
  On the first day of September in Keene, New Hampshire, sunrise is at 6:13 am and sunset at 7:24 pm. On the last day of September, in Keene, sunrise is at 6:45 am and sunset at 6:33 pm EDT.
• Bedford - September »
  On the first day of September in Bedford sunrise is at 6:10 am and sunset at 7:21 pm. In Bedford, during September, the rain falls for 8.4 days and regularly aggregates up to 0.79" (20mm) of precipitation.