September Weather in Northampton, United States

Last updated: June 24, 2025

In September, the average temperature in Northampton, United States is a pleasant 18°C (65°F). However, be prepared for a range, as temperatures can dip to a minimum of 2°C (36°F) and soar up to a maximum of 33°C (92°F). Expect about 112 mm (4.4 in) of precipitation over 8 days, accompanied by an average humidity of 72%.

September Temperature in Northampton

In September, in Northampton, the average temperature is 18°C (65°F). The maximum can reach 33°C (92°F), while the minimum can be as low as 2°C (36°F). This temperature range makes Northampton an ideal destination for travelers seeking both warm days and cool nights.

September Weather in Northampton: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Northampton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Northampton, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (92°F) and lows dropping to around 2°C (36°F).
JanFebMarAprMayJunJulAugSepOctNovDec283036475868737265544032
Data source: Temperature data for Northampton generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Northampton

In Northampton in September, the total precipitation amount is 112 mm (4.4 in) spread over 8 days.

September Precipitation Trends in Northampton

The chart displays monthly precipitation patterns in Northampton, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Northampton, September typically receives around 112 mm (4.4 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec7997851441098915810611215697123
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Northampton

In Northampton in September humidity is 72%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace, making traveling somewhat uncomfortable as the air clings to your skin and the heat can be stifling, yet it's perfect for enjoying leisurely strolls under the shade.

September Average Humidity in Northampton

This chart illustrates the average monthly humidity levels in Northampton, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Northampton is approximately 72%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%88%86%84%76%72%67%64%72%81%87%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Northampton

In Northampton in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Northampton.

Maximum UV Index Levels in Northampton for September

The chart shows the monthly maximum UV Index (UVI) for Northampton in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Northampton typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35681010998642
Data source: Northampton September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Northampton Compares to Other Months

Weather in Northampton varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Northampton, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Northampton, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (28°F)79 mm (3.1 inches)89%moderate
February Weather-1°C (31°F)97 mm (3.8 inches)88%moderate
March Weather2°C (36°F)85 mm (3.4 inches)86%high
April Weather8°C (48°F)144 mm (5.7 inches)84%very high
May Weather15°C (59°F)109 mm (4.3 inches)76%very high
June Weather20°C (68°F)89 mm (3.5 inches)72%very high
July Weather23°C (73°F)158 mm (6.2 inches)66%very high
August Weather22°C (72°F)106 mm (4.2 inches)64%very high
September Weather18°C (65°F)112 mm (4.4 inches)72%very high
October Weather12°C (54°F)156 mm (6.2 inches)81%high
November Weather5°C (41°F)97 mm (3.8 inches)87%moderate
December Weather0°C (32°F)123 mm (4.8 inches)84%low

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