Housing Inventory: Median Days on Market in San Mateo County, CA was 25.00000 Level in February of 2026, according to the United States Federal Reserve. Historically, Housing Inventory: Median Days on Market in San Mateo County, CA reached a record high of 80.00000 in December of 2021 and a record low of 15.00000 in February of 2018. Trading Economics provides the current actual value, an historical data chart and related indicators for Housing Inventory: Median Days on Market in San Mateo County, CA - last updated from the United States Federal Reserve on April of 2026.