INDIANAPOLIS — September is known a transition month in central Indiana and can produce a wide range of temperatures.
The next 48-72 hours will be a perfect example of that with the temperature pendulum swinging from the 50s tonight and Saturday morning to the 90s Sunday afternoon.
This is the result of comfortably dry air in place currently over the Ohio Valley with dewpoints in the 40s and 50s that delivers pleasant lows. A wind shift to the southwest this weekend, combined with hazy sunshine, boosts high temperatures into the 80s Saturday and 90°+ Sunday.
The only thing that could keep highs from reaching the 90s is an expected increase of remnant wildfire smoke that's modeled to increase from the west over the weekend. Latest modeling suggests this will be well aloft, so it's conceivable it may have little impact to temperatures.
It will definitely dim the blue sky and create the "fiery" sunrise and sunsets. This bout of wildfire smoke and heat lingers into the middle of next week. Temperatures in the 90s in September are not uncommon. Since 1871, Indianapolis averages about two days in September of 90°+.
