A strong ridge of high pressure will keep our skies sunny (although some haze is likely) and our temperatures generally mild, although overnight low temperatures will be quite cold. The high pressure ridge sitting over us will cap some pretty strong inversions and thus air quality is likely to deteriorate as we head through the week. The pattern remains essentially unchanged for the next seven days.

Foundation vent 2

Yesterday I asked whether one should close foundation vents in the winter. While it makes sense on the surface to close them, I have had several building experts tell me that it is a bad idea. The problem is that closed vents can trap moisture under your home, and that can lead to moisture condensation along the rim joists and mud sill. In addition to that, mold and fungus not only like moisture, they also prefer a steady temperature. With the vents closed, the lack of temperature differences in the day and nighttimes could promote mold and fungus growth.

foundation vent 3

How your crawl space is insulated might come into play. Check under your crawl space. If your foundation is insulated, you will have to make a decision whether you prefer moisture under the house (closed vents), or higher heating bills (open vents). Insulating the sub floor instead of the foundation is a good solution to solve both problems, since you can keep the vents open without losing heat.