The National Weather Service issued a Frost Advisory for several counties across the Chicago area starting late Friday and lasting through early Saturday.
Winnebago, McHenry, Boone, Lake (IL), Ogle, Lee, De Kalb, Kane, DuPage, La Salle, Kendall, Grundy, Kankakee, Livingston, Iroquois and Ford counties are all under the Frost Advisory, which warns of temperatures falling into the low-to-mid 30s overnight.
Temperatures could drop below freezing "for a time" early Saturday morning, according to the advisory.
The alert takes effect beginning at midnight Friday and is scheduled to expire at 8 a.m. Saturday morning.
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The National Weather Service warned that the frost could kill sensitive outdoor vegetation if left uncovered.
After the frost clears Saturday morning, the rest of the day is expected to be mostly to partly sunny, breezy and cool. Temperatures highs will likely be in the mid-to-upper 50s in most areas.
Sunday will likely be partly cloudy in the morning with more coverage moving in throughout the day. According to the NBC 5 Storm Team, showers and storms could develop by the afternoon.