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May Weather in Rock Falls, United States

Last updated: June 24, 2025

In Rock Falls, United States, the average temperature in May hovers around 17°C (62°F), with extremes ranging from a chilly -1°C (30°F) to a toasty 34°C (94°F). During this month, expect approximately 157 mm (6.2 in) of precipitation over about 16 days, contributing to an average humidity of 79%. Whether you’re exploring the local sights or enjoying the weather, be prepared for the dynamic climate!

May Temperature in Rock Falls

In May in Rock Falls, the average temperature is 17°C (62°F), with maximums reaching up to 34°C (94°F) and minimums dropping as low as -1°C (30°F). This diverse temperature range makes Rock Falls an ideal destination for travelers seeking both warm and cooler weather experiences.

May Weather in Rock Falls: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Rock Falls, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rock Falls, May typically has an average temperature of 17°C (62°F), with highs reaching up to 34°C (94°F) and lows dropping to around -1°C (30°F).
JanFebMarAprMayJunJulAugSepOctNovDec232640496273767368543932
Data source: Temperature data for Rock Falls generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Rock Falls

In Rock Falls in May, the total precipitation amount is 157 mm (6.2 in) spread over 16 days.

May Precipitation Trends in Rock Falls

The chart displays monthly precipitation patterns in Rock Falls, 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 Rock Falls, May typically receives around 157 mm (6.2 inches) of precipitation spread over approximately 16 days.
JanFebMarAprMayJunJulAugSepOctNovDec59598611015714198731151155250
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Rock Falls

In Rock Falls in May humidity is 79%. With an average temperature of 17°C (62°F), this humidity feels like a warm blanket wrapping around you, making strolling through the streets a bit heavier but still comfortably refreshing for travelers.

May Average Humidity in Rock Falls

This chart illustrates the average monthly humidity levels in Rock Falls, 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 Rock Falls is approximately 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%83%84%85%79%82%80%81%80%82%88%84%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Rock Falls

In Rock Falls 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 Rock Falls.

Maximum UV Index Levels in Rock Falls for May

The chart shows the monthly maximum UV Index (UVI) for Rock Falls 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 Rock Falls typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35689101098642
Data source: Rock Falls 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 Rock Falls Compares to Other Months

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

This table compares monthly weather conditions in Rock Falls, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-5°C (24°F)59 mm (2.3 inches)82%moderate
February Weather-3°C (26°F)59 mm (2.3 inches)83%moderate
March Weather4°C (40°F)86 mm (3.4 inches)84%high
April Weather9°C (49°F)110 mm (4.3 inches)85%very high
May Weather17°C (62°F)157 mm (6.2 inches)79%very high
June Weather23°C (73°F)141 mm (5.6 inches)82%very high
July Weather24°C (76°F)98 mm (3.8 inches)80%very high
August Weather23°C (73°F)73 mm (2.9 inches)81%very high
September Weather20°C (68°F)115 mm (4.5 inches)80%very high
October Weather12°C (54°F)115 mm (4.5 inches)82%high
November Weather4°C (39°F)51 mm (2.0 inches)88%moderate
December Weather0°C (32°F)50 mm (2.0 inches)84%low

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