On March 4, the Washington State Senate passed SB 5171, which moves the primary (for office other than President) from late August to early August. The filing deadline moves three weeks earlier, into late April. The bill passed with only one “no” vote.
Washington uses a top-two system. One of the disadvantages of that system is that all avenues to the November ballot are shut off early in the year (except for write-ins). In a traditional system, even if the major parties choose their nominees in the first half of the year, there is usually a method for independent candidates, or new parties, to get on the ballot later. This flexibility is useful if some important and unexpected public event occurs in the middle of the year, to make it possible for voters to support someone entering the race late, in response to that unexpected event.