nomadseason

May Weather in Cornwall, United States

Last updated: June 24, 2025

In Cornwall, United States, the average temperature in May is a pleasant 15°C (60°F). However, temperatures can vary, dipping to a chilly 0°C (32°F) at their lowest and soaring to a warm 33°C (92°F) at their peak. This month sees approximately 119 mm (4.7 in) of precipitation spread over 13 days, contributing to an average humidity of 69%.

May Temperature in Cornwall

In May in Cornwall, the average temperature is 15°C (60°F). Maximums can reach 33°C (92°F), and minimums can be as low as 0°C (32°F). This varied climate makes Cornwall an ideal destination for travelers seeking both warm and cool experiences throughout the month.

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

The chart illustrates May temperature patterns in Cornwall, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Cornwall, May typically has an average temperature of 15°C (60°F), with highs reaching up to 33°C (92°F) and lows dropping to around 0°C (32°F).
JanFebMarAprMayJunJulAugSepOctNovDec303339496069757366564234
Data source: Temperature data for Cornwall generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Cornwall

In Cornwall in May, the precipitation amount is 119 mm (4.7 in) spread over 13 days.

May Precipitation Trends in Cornwall

The chart displays monthly precipitation patterns in Cornwall, 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 Cornwall, May typically receives around 119 mm (4.7 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec6995881181199512912111514190102
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

May Humidity in Cornwall

In Cornwall in May, humidity is 69%. With an average temperature of 15°C (60°F), this humidity feels like a cool, damp embrace that can make outdoor activities feel slightly heavier and more exhausting, but still inviting for exploring the charming sights and sounds of the area.

May Average Humidity in Cornwall

This chart illustrates the average monthly humidity levels in Cornwall, 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 Cornwall is approximately 69%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%82%81%78%70%69%62%65%68%74%82%80%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Cornwall

In Cornwall 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 Cornwall.

Maximum UV Index Levels in Cornwall for May

The chart shows the monthly maximum UV Index (UVI) for Cornwall 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 Cornwall typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356810101098642
Data source: Cornwall 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 Cornwall Compares to Other Months

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

This table compares monthly weather conditions in Cornwall, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-1°C (31°F)69 mm (2.7 inches)84%moderate
February Weather1°C (33°F)95 mm (3.7 inches)82%moderate
March Weather4°C (39°F)88 mm (3.5 inches)81%high
April Weather10°C (50°F)118 mm (4.6 inches)78%very high
May Weather15°C (60°F)119 mm (4.7 inches)69%very high
June Weather20°C (69°F)95 mm (3.7 inches)69%very high
July Weather24°C (75°F)129 mm (5.1 inches)62%very high
August Weather23°C (73°F)121 mm (4.8 inches)65%very high
September Weather19°C (67°F)115 mm (4.5 inches)68%very high
October Weather14°C (57°F)141 mm (5.5 inches)74%high
November Weather6°C (42°F)90 mm (3.5 inches)82%moderate
December Weather1°C (35°F)102 mm (4.0 inches)80%low

Compare Cornwall's Climate with Cities Worldwide