September Weather in Altona, United States

Last updated: June 24, 2025

In September, the average temperature in Altona, United States sits at a comfortable 16°C (61°F). However, be prepared for temperature fluctuations, with a minimum of -3°C (26°F) and a maximum soaring to 34°C (93°F). Expect 42 mm (1.7 in) of precipitation spread over 9 days, alongside an average humidity level of 63%. It's a month of varied weather, so pack accordingly!

September Temperature in Altona

In September in Altona, the average temperature is 16°C (61°F), with maximums reaching 34°C (93°F) and minimums dropping as low as -3°C (26°F). This varied climate makes it important for travelers to pack accordingly, ensuring comfort for both warm and cool conditions.

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

The chart illustrates September temperature patterns in Altona, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Altona, September typically has an average temperature of 16°C (61°F), with highs reaching up to 34°C (93°F) and lows dropping to around -3°C (26°F).
JanFebMarAprMayJunJulAugSepOctNovDec262635425063686661443629
Data source: Temperature data for Altona 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 Altona

In Altona in September, the precipitation amount is 42 mm (1.7 in) spread over 9 days.

September Precipitation Trends in Altona

The chart displays monthly precipitation patterns in Altona, 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 Altona, September typically receives around 42 mm (1.7 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec2537646913680908142473021
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Altona

In Altona in September humidity is 63%. With an average temperature of 16°C (61°F), this humidity feels like a soft, damp blanket wrapping around you, making outdoor excursions a bit muggy but manageable.

September Average Humidity in Altona

This chart illustrates the average monthly humidity levels in Altona, 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 Altona is approximately 63%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%86%75%67%67%68%62%63%63%72%80%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Altona

In Altona 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 Altona.

Maximum UV Index Levels in Altona for September

The chart shows the monthly maximum UV Index (UVI) for Altona 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 Altona typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec46811111212119643
Data source: Altona 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 Altona Compares to Other Months

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

This table compares monthly weather conditions in Altona, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-3°C (27°F)25 mm (1.0 inches)84%moderate
February Weather-4°C (26°F)37 mm (1.5 inches)85%high
March Weather2°C (35°F)64 mm (2.5 inches)75%very high
April Weather5°C (42°F)69 mm (2.7 inches)67%extreme
May Weather10°C (50°F)136 mm (5.4 inches)67%extreme
June Weather17°C (63°F)80 mm (3.2 inches)68%extreme
July Weather20°C (68°F)89 mm (3.5 inches)62%extreme
August Weather19°C (67°F)81 mm (3.2 inches)63%extreme
September Weather16°C (61°F)42 mm (1.7 inches)63%very high
October Weather7°C (45°F)47 mm (1.9 inches)72%high
November Weather2°C (36°F)30 mm (1.2 inches)79%moderate
December Weather-1°C (30°F)21 mm (0.8 inches)85%moderate

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