Lady Gaga joined her fiancé Taylor Kinney and others jumping into the frigid waters of Lake Michigan during the 16th Annual Chicago Polar Plunge at North Avenue Beach Sunday. Credit: Ashlee Rezin/Sun-Times

Welcome to the Reader‘s morning briefing for Monday, March 7, 2016.

  • Weather: Warm with a chance of rain

We’re getting a touch of early spring, with a high of 53 and a low of 50. It will be cloudy, and there’s a chance of rain in the morning and afternoon. [AccuWeather]

  • Rahm sits out the Polar Plunge while Lady Gaga gets in cold Lake Michigan

We have to give Lady Gaga credit—she jumped in Lake Michigan to raise money for Special Olympics Chicago for the second year in a row Sunday morning. She was accompanied by her fiancé, Chicago Fire star Taylor Kinney, and other cast members from Chicago Fire, Chicago P.D., and Chicago Med. They weren’t the only celebrities in attendance: the Today Show‘s Al Roker and Dylan Dreyer also jumped in. Mayor Rahm Emanuel was there but didn’t get in the water. [Tribune]

  • Nancy Reagan’s Chicago childhood

Former first lady Nancy Reagan passed away in Los Angeles Sunday at age 94, and Chicago played a very important role in her long, storied life. Most Chicagoans probably don’t know that she worked at Marshall Field’s as a sales clerk after graduating from the Latin School and before attending Smith College. [Tribune]

  • Man stabbed at CTA Belmont Red Line stop for “no apparent reason”

A 26-year-old man was stabbed as he exited a train at the Belmont Red Line stop in Lakeview around 3:30 AM Sunday. There is a suspect, but police have not released his description. [ABC7 Chicago]

  • Petition puts pressure on UIC to cancel controversial Donald Trump rally

    Republican presidential candidate Donald Trump is hosting a free rally at UIC Pavilion Friday night, and so far more than 40,000 people have signed a petition to cancel the event. Two of his Republican rivals, Senator Ted Cruz and Governor John Kasich, will also be making campaign stops in the Chicago area this week ahead of Illinois’s March 15 primary. [CBS Chicago]