If you traveled anywhere near the Twin Cities the last couple of days, you may have seen some MnDot signs that read, "Air Quality Alert. Refuel after Dusk." I had not recalled seeing that ever before. So I wanted to do some digging to find out what that meant.

KARE 11 Meteorologist Sven Sundgaard pointed out why. Pumping gas into your vehicle releases VOC's. (Volatile Organic Compounds)and in the extreme heat and strong sun, it creates Ozone. Ozone in the stratosphere is good. It helps protect us from the harmful rays of the sun. Ground level Ozone causes us to have breathing problems or in the case of the elderly or those with asthma or other lung issues it can be extra hard on them.

And ground-level ozone tends to increase dramatically on these hot steamy days. It makes sense now. Besides waiting to fuel after dark is probably better in another way. It will be much more comfortable standing at the pump with the sun setting.

Getty Images