The October whiplash is in full swing. The San Joaquin Valley’s dirty air suddenly made a comeback in the last 10 days, then just as quickly vanished in a storm Monday.
Just a few weeks ago, I had written that the Valley has a good shot at the lowest-ever recorded number of federal eight-hour ozone exceedances. With a rash of exceedances — eight since Oct. 19 — it’s going to be close.
The total now is 91. The record is 93.
South Coast Air Basin in Southern California has 94 exceedances right now. The region has had only one ozone November exceedance in the last five years.
It’s possible the Valley could wind up with more than South Coast this year. That would mean the Valley would have the most in the nation.
There’s another issue in the Valley. A reader points out high hourly readings for tiny particle pollution, wondering why the residential wood-burning ban doesn’t start in October. Right now, the rule kicks in Nov. 1 each year.
As I understand it, the tiny particle threshold — known as the standard for PM-2.5 — is an average over 24 hours. So hourly readings, by themselves, are not considered exceedances.
But the reader pointed out some pretty high hourly readings, saying October is known for these problems. It might be worth taking a longer look at this point.
Remember, wood-burning restrictions begin Friday. Check with the San Joaquin Valley Air Pollution Control District’s web site to see if wood-burning is allowed in your county before you light up.