So far, Louisville’s air has been fairly healthy this summer: there haven’t been any ozone exceedences.

But the first one could come on Friday. The Louisville Air Pollution Control District has issued the third air quality alert of 2013. The Air Quality Index is forecast to be 133, which is unhealthy for sensitive groups. 

These sensitive groups include the elderly, the young, and anyone with heart or lung ailments.

Ozone is formed when pollution from cars and factories cooks under the sun. On bad air days, the Air Pollution Control District recommends Louisville residents avoid idling vehicles, share rides, delay mowing lawns or getting gas and try to combine errands to help improve the air quality.

You can check the air in real-time by clicking here and entering your zip code.

Erica Peterson reports on energy and the environment for WFPL. She is also Enterprise Editor.