Fresno County as of a few weeks ago, has downgraded from purple category (the most severe) to red category (one step below purple). This means fewer restrictions for businesses and the like, including schools. If a county doesn’t relapse back into the purple category, then schools can open so long as 14 consecutive days (of being in the red zone) have passed. However, in the event that Fresno County returns to being in the purple zone after some schools have already applied for waivers, in which they can still reopen.
However, there’s plenty of things that can go wrong. Schools are in enclosed spaces, kids aren’t (nor should you expect them to be) always methodological, generally don’t have the best hygiene/sanitary habits, and with the lack of rapid testing (or testing in general) and no COVID-19 vaccine in sight, I would imagine that reopening schools right now would be irresponsible. It will be a great challenge for everyone, but nevertheless, schools can reopen safely. Maybe just not now; in a few months maybe, if Fresno becomes orange or yellow (categories below purple and red).