Election Day is Tuesday, Nov. 3. San Mateo County runs its election with vote centers, and any voter can use any center. Here is what you need to know.

Where to vote

The county elections office says 50 vote centers open on Monday, Nov. 2, from 9 a.m. to 5 p.m. On Election Day they are open from 7 a.m. to 8 p.m. You can also drop your mail ballot in an official drop box. A mailed ballot counts only if it is postmarked on or before Election Day and arrives within seven days.

If you make a mistake on your ballot, you can ask for a replacement. If you missed the registration deadline, you can still register and vote at a vote center under Conditional Voter Registration.

Ballots already in

As of 5 p.m. on Oct. 29, the county had received 116,235 mail ballots and 2,104 ballots at vote centers. The county calls this a raw estimate that is updated daily.

County measures

NBC Bay Area named Measure U, Redwood City's Measure E and Half Moon Bay's Measure Q as ones to watch. Our explainers:

City measures

The county list also has Measure L (extreme weather), the Regional Transit Measure, school measures in Burlingame, Cabrillo, Jefferson Union, San Carlos and San Mateo-Foster City, and city measures in Belmont, Brisbane, Burlingame, East Palo Alto (O and CC), Half Moon Bay (Q), Pacifica (BB), Portola Valley (N), San Bruno (S), San Carlos and San Mateo (H and F).

Races

See our guides to the District 5 supervisor race and the San Mateo City Council races.

How to vote

Election Day is Tuesday, Nov. 3. Polls and vote centers close at 8 p.m., and mailed ballots must be postmarked by Election Day and arrive within seven days. You can check your registration and ballot status at sos.ca.gov/elections. California lets you register and vote the same day at a vote center.