CHICAGO (CBS) -- We've made it to the middle of the week and are greeted with some stagnant weather.

Air quality alert is in effect until midnight for most of the DMA - unhealthy for sensitive groups. The primary pollutant will be ozone.

Temperatures will become fairly hot this weekend as we get close to 90 by Saturday. The next rain chance is on Sunday with a passing storm system. We will likely not get much from it...1/4 of an inch if we are lucky.

But it will cool down on the other side of the system early next week.

TODAY: MOSTLY SUNNY, WARM, AND DRY. COOLER LAKESIDE.  HIGH 85

TONIGHT: MOSTLY CLEAR AND COMFORTABLE. LOW 66

THURSDAY: MOSTLY SUNNY AND WARM. HIGH 82