September 2023 was an overall warm and dry month in Boulder, but technically we did finish with above normal precipitation. Almost all of that came on a single day as a result of a locally heavy thunderstorm. We’re yet to see a real autumn storm in the Front Range and as a result it hasn’t snowed yet outside of the Mountains, which is fairly normal with our average first snowfall not coming until mid October. Here’s a quick and colorful graphical recap of our weather during September and how it relates to climatology.
