In my coronavirus trackers and simulations revisited post, I have updated the CDC link o their new “COVID-19 by County” page based on guidance issued Friday, February 26 (it’s 2022 in case you are an anthropologist reading this thousands of years in the future.) The updated recommendation is to mask indoors if new cases in your county are 200,000 per 100,000 population per week, AND if the number of people entering the hospital and/or in the hospital is above certain thresholds. It’s a little hard to find the data and figure out yourself, so if you trust the CDC (and who wouldn’t?) you can just type in your county and they will tell you if it is high/medium/low. My home county of Philadelphia is in the medium category, indicating we don’t need to mask indoors, but the city will be slow to react and the school district will be even slower if they react at all.