This terminology is used by general contractors in the construction trades. In fact, contracts often have built-in stipulations pertaining to the effects of adverse weather conditions on scheduled completion of work.
Contractors use local weather statistics, usually from NOAA, to determine the mean number of days each month that may obstruct work progress or cause delays. Such disruptions are factored into the project work schedules. These adverse weather days may be associated with storm fronts, excessive wetness, extreme wind, or extreme temperature conditions.
When the number of adverse weather days exceeds the climatological average for a specific location, the contractor may request an extension to the work schedule. In this approach to contracting, historical climate is factored into the planned completion schedule for each phase of a project, especially those that will take months to years to reach completion.
I suspect such an approach has been taken with construction of the new Gopher football stadium, as well as the new Twins baseball stadium. Generally the mean number of adverse weather days is higher during the winter season, especially in northern climates like Minnesota.