March marks the start meteorological spring and ranks as the city’s fastest warming month, but the weather this year is more reminiscent of mid-winter. Saturday’s highs will reach the middle 30s and that will be the last time temperatures here break the freezing mark until Thursday. A late-season cold wave will send Chicago-area temperatures tumbling as a major snow storm socks the southern Midwest. Area temperatures will fall from the 20s early Sunday, plunging below zero in many location by daybreak Monday. Highs on Monday will struggle to reach double-digits, eradicating the current March 4 record low maximum of 17 degrees set back in 1890. The cold weather will persist, with slow moderation by the end of the week, but with the warm-up comes the threat of snow as another storm system passes through the Ohio Valley.