In the year 2024, according to the page below or best substitute, SF will havew >320 days of "Good" EPA Air Quality Ratings in the year 2024.

This page tracks AQI in SF https://sfgov.org/scorecards/environment/days-epa-air-quality-index-rating-good

The number of good days in past years has been

2019: 313

2020: 277

2021: 310

It may take some time to resolve this since data lags.

If measurement chagnes, we will attempt to use the best substitute for the quality being measured at time of market creation. i.e. figure out what the number would have been had standards not changed. We will not use a new or redefined definition of "good" if one were to come into effect.