May Weather in Harrisburg, United States

Last updated: June 24, 2025

In May, the average temperature in Harrisburg, United States is a pleasant 20°C (69°F). However, be prepared for fluctuations, as temperatures can dip as low as 4°C (39°F) and soar up to 33°C (92°F). Rain is a potential companion this month, with an average precipitation of 128 mm (5.0 in) spread over about 13 days. Keep in mind that the average humidity levels are high at 82%, adding to the overall climate experience.

May Temperature in Harrisburg

In May in Harrisburg, the average temperature is 20°C (69°F). Maximums can reach 33°C (92°F), while minimums can drop to as low as 4°C (39°F). This variation in temperature makes it a perfect time for travelers to enjoy a mix of warm days and cooler nights, allowing for comfortable outdoor activities.

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

The chart illustrates May temperature patterns in Harrisburg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Harrisburg, May typically has an average temperature of 20°C (69°F), with highs reaching up to 33°C (92°F) and lows dropping to around 4°C (39°F).

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

May Precipitation in Harrisburg

In Harrisburg in May, the precipitation amount is 128 mm (5.0 in) spread over 13 days.

May Precipitation Trends in Harrisburg

The chart displays monthly precipitation patterns in Harrisburg, 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 Harrisburg, May typically receives around 128 mm (5.0 inches) of precipitation spread over approximately 13 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 Harrisburg

In Harrisburg in May humidity is 82%. With an average temperature of 20°C (69°F), this humidity feels like a warm, sticky embrace that clings to your skin, making it necessary to stay hydrated while exploring the sights.

May Average Humidity in Harrisburg

This chart illustrates the average monthly humidity levels in Harrisburg, 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 Harrisburg is approximately 82%, 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 Harrisburg

In Harrisburg in May, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Harrisburg.

Maximum UV Index Levels in Harrisburg for May

The chart shows the monthly maximum UV Index (UVI) for Harrisburg 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 Harrisburg typically reaches 11, which falls under the extreme exposure category.

Data source: Harrisburg 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 Harrisburg Compares to Other Months

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

This table compares monthly weather conditions in Harrisburg, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (36°F)	96 mm (3.8 inches)	86%	moderate
February Weather	4°C (39°F)	115 mm (4.5 inches)	84%	high
March Weather	9°C (49°F)	137 mm (5.4 inches)	84%	high
April Weather	14°C (57°F)	134 mm (5.3 inches)	80%	very high
May Weather	20°C (69°F)	128 mm (5.0 inches)	82%	extreme
June Weather	25°C (77°F)	120 mm (4.7 inches)	83%	extreme
July Weather	27°C (80°F)	91 mm (3.6 inches)	79%	very high
August Weather	25°C (78°F)	84 mm (3.3 inches)	76%	very high
September Weather	23°C (74°F)	79 mm (3.1 inches)	75%	very high
October Weather	16°C (61°F)	114 mm (4.5 inches)	74%	high
November Weather	8°C (46°F)	90 mm (3.5 inches)	85%	moderate
December Weather	5°C (42°F)	88 mm (3.5 inches)	88%	moderate