The San Joaquin Valley's clean-air spring is just about over. Figures show state ozone violations have occurred on 10 of the last 12 days.

And Arvin, usually the smog kingpin in the Valley, is not the worst place in the region. Clovis has claimed that spot for now.

Ozone forms best in heat and sunshine. With 90-degree heat on the way this week, there may be more violations on the way.

The Valley already leads California in state violations. The California Air Resources Board revised its data and discovered Clovis in April had two violations of the federal standard, which is more lenient than the state standard.

Clovis also has 20 violations of the state standard -- most in the state. Arvin and Sequoia-Kings Canyon National Parks both have 13.

For total violations over the past five years, Arvin is the worst place in the country. Will Clovis continue to lead the Valley and the state in ozone violations? Only time will tell.