OLYMPIA—Washington’s indoor mask mandate, which was originally scheduled to end March 21, will now be over at 11:59 p.m. March 11.

Gov. Jay Inslee announced the change to the mandate’s end at a press conference Monday, Feb. 28. The move comes in a joint West Coast masking move-on, as Oregon and California will be ending most of their indoor mandates in a similar midnight masquerade.

The first day students won’t be required to wear masks at school will be Monday, March 14 instead of the previously scheduled March 21 date.

“We’ve continued to monitor data from our state Departm...