MADISON, Wis. – Typically, the Madison area picks up nearly 14″ of snow during a normal January. However, January 2025’s total snow accumulation is just over a half an inch. The reason is likely due to the cooler than average air that’s been present through most of the month.
January 2025 is half way over and most of Wisconsin has yet to accumulate over 5″ of snow, according to the Midwestern Regional Climate Center’s cliMATE page. Central and southern Wisconsin especially are lacking snow from the start of the month through January 17th with a large swath of the area accumulating less than 1″ of snow.
With less than two weeks left in January, and long range model’s current data suggesting minimal snow chances through the end of month, what is causing the lack of snow to central and southern Wisconsin? The answer is likely due to strong high pressure systems coming in from Canada.
As their name suggests, high pressure systems are areas of pressure with more pressure than their low pressure system counterparts. This is because from their top to the surface of the Earth, air is sinking or moving towards the surface. Whereas air rises upwards through the atmosphere in a low pressure system.
On weather maps with surface pressure on them, the lower the number represents a low pressure system while the higher the number represents a high pressure system. When high pressure systems are over an area, they’re usually distinguishable by two characteristics – clearer sky conditions along and/or light winds.
The first of these two characteristics, the clearer sky conditions, are especially likely during the winter months because high pressure systems become stronger in cold weather. The reason is because during colder weather, air molecules move slower thus creating a denser, or heavier, airmass. Which makes it harder for clouds, snow or wintry mix to develop over an area.
Since the beginning of January, there have been three days of measurable snow recorded in the Madison area: January 10th, January 15th and January 16th. Also since January started, strong high pressure systems have been coming out of Canada, moving over the Midwest and eventually pushing east into the Atlantic.
Each time one of these high pressure systems move in, they bring with them a large area of cooler, drier and sinking air. All of which is spread over a wide area, the size of a few states, which creates a weather “force field”. While high pressure systems get stronger during the winter months, low pressure systems get weaker…