It’s hazy as the field is prepared for the Mariners to play Oakland in the first game of a double header, Monday at T-Mobile Park in Seattle. Ken Lambert / The Seattle Times

The Mariners’ homestand against the San Francisco Giants just went up in smoke.

More specifically, the game originally scheduled for 6:40 p.m. at T-Mobile Park on Tuesday has been postponed because of poor air quality in the Seattle area, the team announced on Tuesday afternoon. The two-game series will instead be played in San Francisco on Wednesday and Thursday. Game times have yet to be determined.

According to the Air Now website — which uses government monitors for accurate air quality readings — the Air Quality Index for the area surrounding T-Mobile Park was 240 just prior to 2 p.m. on Tuesday. The AQI scale is measured between 0 and 500, with 0-50 being “good” and 200-300 registering as “very unhealthy.”

“Unfortunately, the air quality in Seattle has gotten worse overnight here at T-Mobile Park and it is not clearing at all today. Forecasters expect it to clear late Thursday and into Friday morning,” Mariners president and chief operating officer Kevin Mather said in a statement. “As always, the health and safety of the players, and our staff is our first priority.

“To assure the games could be played, the best solution was to re-locate to the Bay Area. We appreciate the Giants willingness to work with us on this challenge, and we look forward to returning to T-Mobile Park on Friday to host the Padres.”

An air quality alert for the Seattle area has been extended by the National Weather Service through noon on Thursday. The official alert states that “pollutants in smoke can cause burning eyes, aggravate heart and lung diseases, and aggravate other serious health problems. Clean Air Agencies recommend staying at home when possible, limiting outdoor activities, and following medical advice from health care professionals.”

As wildfires tear through parts of California, Oregon and Washington, a layer of smoke arrived in the Seattle area on Friday and has failed to dissipate in the days since. Despite the questionable conditions, the Mariners and A’s completed a doubleheader — with both games lasting seven innings — at T-Mobile Park on Monday.

After the first game, A’s starter Jesus Luzardo said that “I’m a healthy 22-year-old, I shouldn’t be gasping for air, or missing oxygen, when I’m getting to the line. So I’ll leave it at that.”

A’s reliever Jake Diekman also tweeted, “@MLB what’s the cut off for air quality?”

An MLB spokesperson confirmed there is not a set AQI index threshold where a game would have to be postponed, saying, “We advise clubs that they should speak with their local health departments and any other relevant local agencies for guidance on how to proceed.”

Mariners manager Scott Servais said after the conclusion of the doubleheader that none of his players were adversely affected by the conditions.

“It’s one of the reasons you know you got the roof on so you get some backdrop there and you can see the ball when it goes up in the air,” he said. “So no issues there. It’s certainly a little bit different than what you’re used to, but nobody had any problems.”