The Lava Fire currently burning east of I-5 in Siskiyou County tripled in size overnight and has now scorched 13,000 acres, or about 20 square miles. The blaze is hundreds of miles from San Francisco, but as it's taking shape to being the first truly major fire of the season in our half of the state, it could always end up being the first one that impacts our air quality.

Bay Area air quality during fire season has been a depressingly variable thing for the last several years, though no doubt 2020 brought the worst of it — with fires raging for months to our north, south, and east compounded by the fact that so many people were stuck at home and being told to keep their windows shut. And then came September 9, 2020, when a trick of the wind sent tons of smoke from fires in Northern California and Oregon down over San Francisco, turning the sky dark orange and blocking out the sun for a day. Good times.

We could also look back to the miserable week following the Camp Fire in Butte County in November 2018, when the toxic plumes from that tragedy enveloped the entire region for days on end.

The Lava Fire was 20% contained as of Tuesday morning, according to a Cal Fire incident report, but it grew three-fold since Monday night thanks to 50-mile-per-hour winds. As the Chronicle reports, it's burning just outside of Weed, California, in steep and largely inaccessible terrain near Mount Shasta and Lake Shastina. The fire is threatening railway lines that go into Oregon, and on Monday afternoon the fire jumped Highway 97, which now runs through the middle of the blaze.

The hearty June marine layer has kept San Francisco and much of the Bay Area relatively cool the past week despite a scorching heatwave up north and in more inland areas. And that looks to be continuing with partial clouds and highs in the mid-60s through the July 4th weekend, so perhaps the Lava Fire smoke won't be making its way toward us.

And, yes, the Sunday fireworks display at the Embarcadero will likely, as is tradition, be shot up into the fog so you can't really see it. Or you can only see the bottom half of it.