On average, the Cedar Valley will get its first taste of frost around September 28th, according to The Old Farmer's Almanac. The National Weather Service puts its estimate at around September 27th. 

In 2019, Waterloo received its first sub-32* temperature of the season on October 12th.

In 2018, Waterloo it was October 14th before we had sub-freezing temps; and in 2017, it didn't occur until October 16th.

So, if those trends continue, we may have a few weeks remaining of the growing season.

Nearly all of Minnesota has either a Frost Advisory or Frost Warning already this month. (September 9th)