INDIANAPOLIS – It has been 10 days since our last 90 degree high in Indianapolis, but it would be shocking if we did not exceed the mark at least a couple times in the next week. Central Indiana is not alone however, a the majority of the US is joining us in starting the month of August with some serious heat.

Expansive ridge distributes high heat

A strong ridge is expanding across the US this week and is the culprit for what will be record warmth across many regions. Pictured below is a map of 500mb heights across the US. This indicates the height at which you would have to travel for the air pressure to fall to 500 millibars (roughly half that at sea level).

This is important meteorologically because it’s a good indicator of the large scale weather pattern. Because warm air expands, we can conclude that the overall air mass is warmer when the 500mb level is higher up. In this case of this week, 500mb heights will be anomalously high across nearly the entire US. This will support widespread above to well above average temperatures. Highs in the triple digits will be possible all the way from Massachusetts to Montana!

Indiana’s slice of this week’s heat

Indiana will run it back to 90 degrees as soon as Tuesday with this hot air mass taking hold. Rain chances will remain low outside of Southwest Indiana and a partly cloudy sky will help us reach the mark. Humidity will be higher end and is the main deterrent of even higher heat, though it will certainly make it feel hotter. Wednesday is expected to be the hottest day this week with highs in the 92-95 range. Rain chances will remain low once again, but humidity will make it feel like it’s in the low 100s!

Thursday & Friday may be a tad cooler, but this is largely because storms return to the forecast. More widespread activity is expected on Thursday with a low chance for severe weather. Feels-like temps will still reach well into the 90s. Friday will feature isolated storm chances and a brief reprieve from high heat & humidity, but it should not be difficult for feels-like temps to scrape 90 once more.

High heat and humidity will continue to increase once more by the weekend.