After a few places this Saturday evening saw some sprinkles, rain will become more widespread overnight and for the early parts of Sunday. While no big rain totals will come from tomorrow's rain, the best time to see some light showers will be in the morning and through the early afternoon hours Sunday.
With a lake breeze coming off of Lake Michigan all-day Sunday, temperatures will struggle to get out of the upper 60's for high temperatures. The last time Rockford saw a high in the 60's was back on June 16, where the official high temperature at the Chicago Rockford International Airport reached 68°.
Most of Sunday afternoon and evening will be dry but rather overcast. These conditions will go into the start of the work week on Monday, which is when changes will begin in our region.
Beginning late Sunday, wind will shift from coming off of Lake Michigan (East), eventually coming out of the South Southeast. Whenever winds come from the south, it means that more moist, humid air will make way into our region. This will occur with a big heat dome that will form during the beginning of the week.
High temperatures Monday will be in the upper 70's, which is when summer-like conditions will begin. Tuesday and Wednesday both call for highs in the upper 80's, which is 10-11° above normal. This moist air will also create summer-like dew points near 70° and at times just above that. This means it will not only feel warmer outside, but more humid too.
While there are only a couple of days in the 80's forecast this next week, the Climate Prediction Center says that going through Mid-September, above normal temperatures are favored throughout the entire contiguous United States.