Updated 09.01.21 @ 7:30a
Welcome to fall- at least from a meteorological perspective! Averages in Indianapolis for the month of September include highs that fall from 82.6° on the 1st to 72.7° at month’s end. Lows drop from the lower 60s (62.5°) to the low 50s (51.6°). We average 3.2″ of rainfall during the month.
As we look at September 2021, the month will get off to a cooler than normal start, but we don’t think we’re quite done with the warmer temperatures. The MJO is forecast to rumble into the notorious warm phases for September and the EPO is showing signs of wanting to spend most of the time in a positive manner.
We’ll take this into account, along with factoring in the trends from the latest longer range computer models (European Weeklies, CFSv2, and JMA) to build our September forecast:
Summed up, we’re talking about a month that is very near seasonal norms from a temperature perspective (once all is said and done) and slightly wetter than average.