May Weather in Lewistown, United States

Last updated: June 24, 2025

In Lewistown, United States, the average temperature in May is a pleasant 18°C (64°F). However, temperatures can range from a chilly 0°C (32°F) to a warm 36°C (97°F). Expect 169 mm (6.7 in) of precipitation over the course of 15 days, accompanied by average humidity levels of 78%. Stay prepared for varied weather conditions!

May Temperature in Lewistown

In May in Lewistown, the average temperature is 18°C (64°F). The maximum can reach 36°C (97°F) and the minimum can be as low as 0°C (32°F). Be prepared for a wide range of temperatures, and pack accordingly for your trip!

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

The chart illustrates May temperature patterns in Lewistown, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lewistown, May typically has an average temperature of 18°C (64°F), with highs reaching up to 36°C (97°F) and lows dropping to around 0°C (32°F).

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

May Precipitation in Lewistown

In Lewistown in May, the precipitation amount is 169 mm (6.7 in) over a span of 15 days.

May Precipitation Trends in Lewistown

The chart displays monthly precipitation patterns in Lewistown, 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 Lewistown, May typically receives around 169 mm (6.7 inches) of precipitation spread over approximately 15 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 Lewistown

In Lewistown in May, humidity is 78%. With an average temperature of 18°C (64°F), this humidity feels like a warm, thick blanket wrapping around you, making traveling feel a bit sticky and sluggish, yet the coolness of the air tempers the intensity, inviting you to explore at a leisurely pace.

May Average Humidity in Lewistown

This chart illustrates the average monthly humidity levels in Lewistown, 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 Lewistown is approximately 78%, 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 Lewistown

In Lewistown in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Lewistown.

Maximum UV Index Levels in Lewistown for May

The chart shows the monthly maximum UV Index (UVI) for Lewistown 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 Lewistown typically reaches 10, which falls under the very high exposure category.

Data source: Lewistown 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 Lewistown Compares to Other Months

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

This table compares monthly weather conditions in Lewistown, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	60 mm (2.4 inches)	81%	moderate
February Weather	-1°C (30°F)	68 mm (2.7 inches)	81%	moderate
March Weather	6°C (42°F)	121 mm (4.8 inches)	81%	high
April Weather	11°C (51°F)	108 mm (4.3 inches)	82%	very high
May Weather	18°C (64°F)	169 mm (6.7 inches)	78%	very high
June Weather	24°C (75°F)	152 mm (6.0 inches)	81%	extreme
July Weather	25°C (78°F)	103 mm (4.0 inches)	79%	very high
August Weather	24°C (75°F)	86 mm (3.4 inches)	77%	very high
September Weather	21°C (70°F)	74 mm (2.9 inches)	78%	very high
October Weather	13°C (56°F)	117 mm (4.6 inches)	78%	high
November Weather	5°C (41°F)	57 mm (2.2 inches)	87%	moderate
December Weather	1°C (35°F)	52 mm (2.0 inches)	84%	low