Windows are generally cheapest during late fall and winter, particularly from November through February. This is the off-season for home improvement projects, so demand for window installation drops significantly. Contractors and manufacturers often offer discounts to keep business steady during slower months.
You can find deals around Black Friday and post-holiday sales as well. Buying during this period can save you 10 to 20 percent compared to peak season prices in spring and summer, when renovation activity surges.