May Weather in Crystal Lake, United States

Last updated: June 24, 2025

In May, the average temperature in Crystal Lake, United States hovers around 15°C (59°F). However, be prepared for a range of conditions, as temperatures can drop to a minimum of 1°C (34°F) and soar to a maximum of 34°C (93°F). During this time, expect 110 mm (4.3 in) of precipitation spread across approximately 12 days, with an average humidity level of 69%.

May Temperature in Crystal Lake

In May in Crystal Lake, the average temperature is 15°C (59°F). Maximum temperatures can reach 34°C (93°F), while minimums can drop to a chilly 1°C (34°F). Make sure to pack both light summer clothes and warmer layers for your trip!

May Weather in Crystal Lake: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Crystal Lake, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Crystal Lake, May typically has an average temperature of 15°C (59°F), with highs reaching up to 34°C (93°F) and lows dropping to around 1°C (34°F).
JanFebMarAprMayJunJulAugSepOctNovDec303238485969747366554233
Data source: Temperature data for Crystal Lake 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 Crystal Lake

In Crystal Lake in May, the precipitation amount is 110 mm (4.3 in) over a span of 12 days.

May Precipitation Trends in Crystal Lake

The chart displays monthly precipitation patterns in Crystal Lake, 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 Crystal Lake, May typically receives around 110 mm (4.3 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec698885128110801418610113892121
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Crystal Lake

In Crystal Lake in May humidity is 69%. With an average temperature of 15°C (59°F), this humidity feels like a mild blanket wrapping around you, making it slightly uncomfortable for traveling; you'll likely find yourself seeking shade and refreshing drinks to stay cool as you explore.

May Average Humidity in Crystal Lake

This chart illustrates the average monthly humidity levels in Crystal Lake, 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 Crystal Lake 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 Crystal Lake

In Crystal Lake 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 Crystal Lake.

Maximum UV Index Levels in Crystal Lake for May

The chart shows the monthly maximum UV Index (UVI) for Crystal Lake 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 Crystal Lake typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3568910998642
Data source: Crystal Lake 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 Crystal Lake Compares to Other Months

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

This table compares monthly weather conditions in Crystal Lake, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-1°C (30°F)69 mm (2.7 inches)84%moderate
February Weather0°C (32°F)88 mm (3.5 inches)82%moderate
March Weather3°C (38°F)85 mm (3.4 inches)81%high
April Weather9°C (49°F)128 mm (5.0 inches)78%very high
May Weather15°C (59°F)110 mm (4.3 inches)69%very high
June Weather20°C (69°F)79 mm (3.1 inches)69%very high
July Weather23°C (74°F)141 mm (5.6 inches)62%very high
August Weather23°C (73°F)86 mm (3.4 inches)65%very high
September Weather19°C (66°F)101 mm (4.0 inches)68%very high
October Weather13°C (56°F)138 mm (5.4 inches)74%high
November Weather5°C (42°F)92 mm (3.6 inches)82%moderate
December Weather1°C (34°F)121 mm (4.8 inches)80%low

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