The weather to begin the month of September has been very pleasant – and very uncommon.

While it is fairly common to have quiet weather patterns and valley fog in September, it is very rare to have such a prolonged period like we have experienced so far this month. “We are stuck in a blocking weather pattern that have the jet stream well north into Canada and only weaker weather disturbances elsewhere in the country’s mid-section,” says National Weather Service Meteorologist Todd Shea.

The National Weather Service office in La Crosse monitors the weather for the area – including Prairie du Chien, Decorah, and Boscobel. Shea says they track conditions with surface observations taken mainly at airports and satellite imagery.

The previous record number of dry days to start the month of September was sixteen, set 116 years ago in 1893.

River valley fog becomes more frequent this time of year primarily due to longer hours of darkness and mature crops that provide ample low-level moisture for fog to form. “This isn’t all valley fog needs to form, though,” says the National Weather Service, “fog that forms because of intense nighttime cooling also needs clear skies and very light winds near the ground.”

“The pattern just didn’t want to budge,” says Shea, “but that will probably change going into next week it appears.”

Does an uncommonly dry and foggy start to the month of September help indicate what kind of weather we experience later in the Fall and Winter? “No, not really,” says Shea, “Our official Winter outlook typically comes out in mid-October.”