Welcome to meteorological fall. While the season doesn't officially begin until September 22 when the sun shines directly on the earth's equator, September through November are known as fall in the meteorology world.
This is the month when we usually get sustained cool temperatures and first frosts. This year shouldn't be any different. While temperatures will cool slightly by the end of the week, they'll slowly rebound for the weekend with highs returning to the 70s. But the one thing you'll notice this month is more frequent cool downs with the cool air lingering longer than before.
Average highs in KELOLAND go from the upper 70s and lower 80s at the beginning of the month to the middle 60s to near 70 at the end. Overnight lows also tumble, from the 50s at the beginning to the 40s at the end. At this time, I see no reason why we'll be above average for temperatures this month, so expect below average temps to continue.
Average rain also takes a hit. In fact, central and western South Dakota usually see just less than two inches for the month while the east is between two and a-quarter to two and three-quarters. I believe our active weather pattern will also continue into September, so don't be surprised to be above average for rain this month.
Mother Nature starts to show her beauty in September as leaves start to change and fall due to the shorter daylight. Enjoy it because we all know that snow will soon be falling.