Above normal temperatures continue to be the rule heading into the second week of May. Area highs on Monday ranged from 80 degrees at Oswego and Plainfield, to the low 60s along lake Michigan. Officially, the high at O’Hare airport reached 75 degrees, a level 8 degrees above the normal for May 7th. Warmer air is due on Tuesday as high pressure slips off to the east, and winds turn southeast. Dry, low dew point air will warm efficiently, allowing 80-degree readings to become more prevalent. Medium range forecasts suggest the current warm spell will persist, with temperatures averaging about 6 degrees above normal through May 22nd. Humidity levels are to rise by Wednesday, raising the likelihood of thunderstorms midweek.