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September Weather in Herculaneum, United States

Last updated: June 24, 2025

In September, the average temperature in Herculaneum, United States is a pleasant 22°C (72°F), with minimums dipping to 8°C (46°F) and maximums soaring up to 35°C (94°F). Expect some rain as the area receives around 68 mm (2.7 in) of precipitation over 7 days. The average humidity sits at a comfortable 76%, making it a season perfect for enjoying the local scenery!

September Temperature in Herculaneum

In September in Herculaneum, the average temperature is 22°C (72°F). Maximums can reach 35°C (94°F), and minimums can be as low as 8°C (46°F). This makes it an ideal time for travelers to enjoy a range of outdoor activities while being prepared for varying weather conditions.

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

The chart illustrates September temperature patterns in Herculaneum, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Herculaneum, September typically has an average temperature of 22°C (72°F), with highs reaching up to 35°C (94°F) and lows dropping to around 8°C (46°F).
JanFebMarAprMayJunJulAugSepOctNovDec333648556776797672594540
Data source: Temperature data for Herculaneum 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 Herculaneum

In Herculaneum in September, the precipitation amount is 68 mm (2.7 in) over the course of 7 days.

September Precipitation Trends in Herculaneum

The chart displays monthly precipitation patterns in Herculaneum, 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 Herculaneum, September typically receives around 68 mm (2.7 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec77841321371438889124691047162
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Herculaneum

In Herculaneum in September humidity is 76%. With an average temperature of 22°C (72°F), this humidity feels like a warm embrace, making travel slightly uncomfortable as you navigate through the thick, saturated air.

September Average Humidity in Herculaneum

This chart illustrates the average monthly humidity levels in Herculaneum, 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 Herculaneum is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%80%82%83%81%80%76%76%85%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Herculaneum

In Herculaneum in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Herculaneum.

Maximum UV Index Levels in Herculaneum for September

The chart shows the monthly maximum UV Index (UVI) for Herculaneum 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 Herculaneum typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3579101110109753
Data source: Herculaneum 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 Herculaneum Compares to Other Months

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

This table compares monthly weather conditions in Herculaneum, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)77 mm (3.0 inches)82%moderate
February Weather2°C (37°F)84 mm (3.3 inches)80%moderate
March Weather9°C (48°F)132 mm (5.2 inches)80%high
April Weather13°C (56°F)137 mm (5.4 inches)80%very high
May Weather19°C (67°F)143 mm (5.6 inches)82%very high
June Weather24°C (76°F)88 mm (3.5 inches)83%extreme
July Weather26°C (80°F)89 mm (3.5 inches)81%very high
August Weather25°C (76°F)124 mm (4.9 inches)80%very high
September Weather22°C (72°F)68 mm (2.7 inches)76%very high
October Weather15°C (59°F)104 mm (4.1 inches)76%high
November Weather7°C (45°F)71 mm (2.8 inches)85%moderate
December Weather4°C (40°F)62 mm (2.5 inches)86%moderate

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