Temperatures across the state might be warming up, but the water temperature in the lake remains cold, in the upper-40s to mid-50s, according to the National Weather Service in Grand Rapids.
The weather service said about 20 percent of people who fall in cold water die within the first minute of immersion because of cold water shock.
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"This cold water can cause a shock to your body with rapid loss of heat and also muscle control," the weather service wrote in a Facebook post Thursday. "Wearing a life jacket and limiting your body's exposure to the water would be wise decisions this weekend."
Temperatures are expected to reach the mid-80s throughout Memorial Day weekend in Grand Rapids and Detroit, according to the weather service offices for both regions.
But Friday the Lake MIchigan water temperature in Holland was 58 degrees.
The Coast Guard says there is also an additional drowning danger in the cold water.
"You jump in thinking it is going to be really warm water and it is not," explains Coast Guard Operations Petty Officer Michael Sheahan at the Grand Haven station. "Your initial reaction is to just gasp and if you are under water you are going to suck in water. That big gulp of water could lead to drowning."
The Coast Guard advises swimmers to put their toe in first and ease into the lake to avoid a shocking surprise.
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Contact Hasan Dudar: hdudar@freepress.com.