January Weather in Grantham, United States

Last updated: June 24, 2025

In January, the average temperature in Grantham, United States hovers around -6°C (22°F). However, it's not uncommon to experience a chilling minimum of -29°C (-20°F), while the mercury can rise to a maximum of 15°C (59°F). Expect about 70 mm (2.7 in) of precipitation spread over 9 days, with an average humidity level of 86%, making it a rather damp month.

January Temperature in Grantham

In January in Grantham, the average temperature is -6°C (22°F). The maximum can reach 15°C (59°F), while the minimum can drop as low as -29°C (-20°F). Be prepared for a wide range of temperatures when traveling to Grantham during this month.

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

The chart illustrates January temperature patterns in Grantham, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grantham, January typically has an average temperature of -6°C (22°F), with highs reaching up to 15°C (59°F) and lows dropping to around -29°C (-20°F).

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

January Precipitation in Grantham

In Grantham in January, the precipitation amount is 70 mm (2.7 in) over the course of 9 days.

January Precipitation Trends in Grantham

The chart displays monthly precipitation patterns in Grantham, 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 Grantham, January typically receives around 70 mm (2.7 inches) of precipitation spread over approximately 9 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Grantham

In Grantham in January humidity is 86%. With an average temperature of -6°C (22°F), this humidity feels like an intense chill that cuts through layers of clothing, making travel uncomfortable and prompting the need for extra warmth and careful planning for outdoor activities.

January Average Humidity in Grantham

This chart illustrates the average monthly humidity levels in Grantham, 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 Grantham 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 Grantham

In Grantham 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 Grantham, you can check the information here.

Maximum UV Index Levels in Grantham for January

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

Data source: Grantham 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 Grantham Compares to Other Months

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

This table compares monthly weather conditions in Grantham, 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 (22°F)	70 mm (2.7 inches)	86%	moderate
February Weather	-4°C (25°F)	81 mm (3.2 inches)	84%	moderate
March Weather	0°C (32°F)	71 mm (2.8 inches)	82%	high
April Weather	6°C (44°F)	116 mm (4.6 inches)	80%	very high
May Weather	13°C (56°F)	78 mm (3.1 inches)	72%	very high
June Weather	19°C (66°F)	85 mm (3.4 inches)	72%	very high
July Weather	22°C (71°F)	120 mm (4.7 inches)	67%	very high
August Weather	21°C (69°F)	86 mm (3.4 inches)	66%	very high
September Weather	17°C (62°F)	64 mm (2.5 inches)	71%	high
October Weather	10°C (50°F)	132 mm (5.2 inches)	78%	moderate
November Weather	2°C (36°F)	100 mm (3.9 inches)	84%	moderate
December Weather	-3°C (27°F)	102 mm (4.0 inches)	81%	low