All City of San Mateo Libraries will be closed on the following days:
2021
- Friday, January 1: New Year's Day Holiday
- Monday, January 18: Martin Luther King, Jr. Holiday
- Monday, February 15: Presidents' Day Holiday
- Monday, May 31: Memorial Day Holiday
- Monday, July 5: Independence Day Holiday (observed)
- Monday, September 6: Labor Day Holiday
- Monday, October 11: Staff Development Day*
- Thursday, November 11: Veterans Day Holiday
- Wednesday, November 24: Day before Thanksgiving - Closing at 5pm
- Thursday, November 25: Thanksgiving Holiday
- Friday, December 24: Christmas Eve
- Saturday, December 25: Christmas Holiday
- Friday, December 31: New Year's Holiday (observed)
*Libraries will be closed for in-service training of Library employees.