A hot weekend is in store for Missouri and Illinois. Afternoon high temperatures will climb into the low to mid 90s both days. The humidity will be slowly increasing through the weekend. Heat indices will be close to the actual temperature Saturday and just a few degrees above Sunday.
By Monday, the humidity levels will be high enough to push the heat index around or a little above 100°.
With mostly sunny skies Saturday, not only will it warm quickly, ground level ozone may be a problem, especially for those with lung illnesses. Air quality was in the Orange category Friday and is expected to be orange again Saturday.
This impacts sensitive groups. Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy exertion outdoors.
The chance of thunderstorms will increase by Tuesday and the cloud cover should keep temperatures in the 80s for highs.
