May Weather in Grantham, United States

Last updated: June 24, 2025

In Grantham, United States, the average temperature in May hovers around 13°C (56°F). During this time, temperatures can fluctuate, with a minimum of -1°C (31°F) and a maximum reaching 33°C (92°F). Expect approximately 78 mm (3.1 in) of precipitation over 11 days, accompanied by an average humidity of 72%. Stay prepared for a mix of weather conditions!

May Temperature in Grantham

In May in Grantham, the average temperature is 13°C (56°F). The maximum can reach 33°C (92°F), and the minimum can be as low as -1°C (31°F). This variation means that travelers should be prepared for both warm and chilly weather during their visit.

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

The chart illustrates May 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, May typically has an average temperature of 13°C (56°F), with highs reaching up to 33°C (92°F) and lows dropping to around -1°C (31°F).

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

May Precipitation in Grantham

In Grantham in May, the precipitation amount is 78 mm (3.1 in) over the course of 11 days.

May Precipitation Trends in Grantham

The chart displays monthly precipitation patterns in Grantham, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Grantham, May typically receives around 78 mm (3.1 inches) of precipitation spread over approximately 11 days.

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

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Millimeters (mm) Inches (in)

May Humidity in Grantham

In Grantham in May, humidity is 72%. With an average temperature of 13°C (56°F), this humidity feels like a damp blanket enveloping you, making outdoor activities somewhat uncomfortable and reminding travelers to stay hydrated and seek shade whenever possible.

May Average Humidity in Grantham

This chart illustrates the average monthly humidity levels in Grantham, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Grantham is approximately 72%, offering insight into how humid the weather typically is during this month.

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

May UV Index in Grantham

In Grantham in May, 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 Grantham.

Maximum UV Index Levels in Grantham for May

The chart shows the monthly maximum UV Index (UVI) for Grantham in May, 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 May, the maximum UV index in Grantham typically reaches 9, which falls under the very high exposure category.

Data source: Grantham May 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 May 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 May’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 May’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