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January Weather in Dayton, United States

Last updated: June 24, 2025

In Dayton, United States, the average temperature in January hovers around -2°C (29°F). Expect a minimum plunge to -26°C (-15°F), while the thermometer can rise to a pleasant 20°C (68°F). With an average precipitation of 100 mm (3.9 in) spread over 13 days, you're likely to experience quite a bit of rain. The air is notably humid, with an average humidity of 89%, making it a uniquely atmospheric month!

January Temperature in Dayton

In January in Dayton, the average temperature is -2°C (29°F), with a maximum that can reach 20°C (68°F) and a minimum that can drop as low as -26°C (-15°F). Travelers should prepare for a wide range of temperatures and pack accordingly.

January Weather in Dayton: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Dayton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Dayton, January typically has an average temperature of -2°C (29°F), with highs reaching up to 20°C (68°F) and lows dropping to around -26°C (-15°F).
JanFebMarAprMayJunJulAugSepOctNovDec283239496068737165554034
Data source: Temperature data for Dayton 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.

January Precipitation in Dayton

In Dayton in January, the total precipitation amount is 100 mm (3.9 in), occurring over a span of 13 days.

January Precipitation Trends in Dayton

The chart displays monthly precipitation patterns in Dayton, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Dayton, January typically receives around 100 mm (3.9 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec100123106135156139137105125128100106
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
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January Humidity in Dayton

In Dayton in January humidity is 89%. With an average temperature of -2°C (29°F), this humidity feels like a suffocating fog that clings to your skin, making outdoor adventures less enjoyable and giving travel a heavy and oppressive feel.

January Average Humidity in Dayton

This chart illustrates the average monthly humidity levels in Dayton, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Dayton is approximately 89%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%90%89%88%80%79%74%64%67%81%89%88%
Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Dayton

In Dayton in January, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Dayton, you can check the information here.

Maximum UV Index Levels in Dayton for January

The chart shows the monthly maximum UV Index (UVI) for Dayton in January, 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 January, the maximum UV index in Dayton typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
Data source: Dayton January 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 January Weather in Dayton Compares to Other Months

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

This table compares monthly weather conditions in Dayton, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (29°F)100 mm (3.9 inches)89%moderate
February Weather0°C (32°F)123 mm (4.8 inches)90%moderate
March Weather4°C (39°F)106 mm (4.2 inches)89%high
April Weather9°C (49°F)135 mm (5.3 inches)88%very high
May Weather15°C (60°F)156 mm (6.1 inches)80%very high
June Weather20°C (68°F)139 mm (5.5 inches)79%very high
July Weather23°C (73°F)137 mm (5.4 inches)74%very high
August Weather22°C (71°F)105 mm (4.1 inches)64%very high
September Weather18°C (65°F)125 mm (4.9 inches)67%very high
October Weather13°C (55°F)128 mm (5.0 inches)81%high
November Weather4°C (40°F)100 mm (3.9 inches)89%moderate
December Weather1°C (34°F)106 mm (4.2 inches)88%low

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