It was a picture-perfect Easter Sunday in Chicago. Temperatures reached the upper 70s, a far cry from last year’s chilly middle 30s, making this the city’s warmest Easter since 2014 when it reached 79. Though not as low as the city’s record, desert-like 12 percent relative humidity, recorded Saturday, it was extremely comfortable Sunday, adding to the day’s delightful weather. The mercury could reach 80 Monday for the first time this year, before dropping to more seasonable 60-degree readings Tuesday, in the wake of a Monday night cold front that threatens scattered showers and thunderstorms. Temperatures the rest of the week should fluctuate between 60s and lower 70s, as a series of weak weather systems traverse the Midwest. While addition shower activity is possible later in the week, limited moisture will inhibit precipitation in the Chicago area, with the heavier totals expected to fall well to the north and south of the city.