Lake Michigan has risen six inches in the past month, according to the National Weather Service, which said the change in water level required an influx of roughly 2.335 trillion gallons of water.
Why is the water level so high now? In a tweet Thursday, the NWS attributed it in large part to "the very wet conditions across the region over the past several months," adding that Chicago had its second-wettest spring on records.
The Chicago area has had 78 days with measurable precipitation so far this year, with 10 days left in June, according to the NWS. That marks the second-highest number for the period of January through June since 1892 and 1878, which both saw 85 days with rain.
With rain in the forecast for several days through the end of the month, it's possible that record could be broken, forecasters said.
Lake Michigan's high water levels were expected to continue through the fall, the NWS said, as water levels have been above the long-term average for the past few years.
The main issue, per the NWS, is an "increased susceptibility to lakeshore flooding and beach erosion, especially during wind events on the lake."
Just last week, part of Chicago's Lakefront Trail was closed for that very issue, as high winds and waves "completely inundated" parts of the city's lakeshore.