January Weather in Decatur, United States

Last updated: June 24, 2025

In January, the average temperature in Decatur, United States is a brisk 6°C (43°F). Expect minimums that can plunge to -12°C (10°F) and maximums that may reach a mild 24°C (75°F). During this month, precipitation amounts total around 98 mm (3.8 in) stretched over 10 days, contributing to an average humidity of a high 86%. Stay prepared for varied weather conditions!

January Temperature in Decatur

In January in Decatur, the average temperature is 6°C (43°F). The maximum can reach 24°C (75°F), and the minimum can be as low as -12°C (10°F). This diverse temperature range means travelers should pack layers to be prepared for both warmer days and chilly nights.

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

The chart illustrates January temperature patterns in Decatur, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Decatur, January typically has an average temperature of 6°C (43°F), with highs reaching up to 24°C (75°F) and lows dropping to around -12°C (10°F).

Data source: Temperature data for Decatur generated using information from the Copernicus Climate Change Service.

January Precipitation in Decatur

In Decatur in January, the precipitation amount is 98 mm (3.8 in) spread over a period of 10 days.

January Precipitation Trends in Decatur

The chart displays monthly precipitation patterns in Decatur, 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 Decatur, January typically receives around 98 mm (3.8 inches) of precipitation spread over approximately 10 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in Decatur

In Decatur in January humidity is 86%. With an average temperature of 6°C (43°F), this humidity feels like a chilling blanket enveloping you, making outdoor exploration feel damp and uncomfortable.

January Average Humidity in Decatur

This chart illustrates the average monthly humidity levels in Decatur, 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 Decatur is approximately 86%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Decatur

In Decatur 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 Decatur, you can check the information here.

Maximum UV Index Levels in Decatur for January

The chart shows the monthly maximum UV Index (UVI) for Decatur 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 Decatur typically reaches 3, which falls under the moderate exposure category.

Data source: Decatur 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 Decatur Compares to Other Months

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

This table compares monthly weather conditions in Decatur, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	6°C (43°F)	98 mm (3.8 inches)	86%	moderate
February Weather	9°C (48°F)	173 mm (6.8 inches)	86%	high
March Weather	12°C (54°F)	162 mm (6.4 inches)	86%	very high
April Weather	16°C (61°F)	152 mm (6.0 inches)	82%	very high
May Weather	21°C (71°F)	120 mm (4.7 inches)	85%	extreme
June Weather	24°C (76°F)	104 mm (4.1 inches)	85%	extreme
July Weather	27°C (80°F)	108 mm (4.2 inches)	83%	extreme
August Weather	26°C (79°F)	114 mm (4.5 inches)	76%	very high
September Weather	24°C (75°F)	93 mm (3.7 inches)	76%	very high
October Weather	18°C (65°F)	124 mm (4.9 inches)	80%	high
November Weather	10°C (51°F)	78 mm (3.1 inches)	88%	moderate
December Weather	8°C (47°F)	133 mm (5.2 inches)	88%	moderate