Post #1227: COVID-19 trend to 8/30/2021, no change

Posted on August 31, 2021

We’re still not at the peak of the Delta wave.  We still seem to be on track for an early-September peak.  US daily new COVID-19 cases per 100,000 population per day stands at 49.6.  It’s up 7% over the last seven days, not materially different from the recent trend. 

South Carolina joins Florida and Mississippi as the states exceeding 100 new cases per 100,000 per day.  Louisiana didn’t report new data, and I suspect that will be true for a while yet.  (I’m holding them in my data at a constant 91 new cases / 100K /day, their last data-based seven-day moving average.)

As with prior waves, there are interesting regional patterns that, to me, at least,  suggest that local climate plays some sort of a role in this.  The entire South-Central region appears to have peaked.  By contrast, excluding Missouri (where this outbreak started), every state in the Midwest and Mountain regions is still seeing new case rates increase.

I find that interesting because those are the regions that started off last year’s winter wave of COVID-19.  And so, I guess a question that we need to start asking is whether this U.S. summer Delta wave will finish before the winter wave gets rolling.

We have some pretty strong clues that the winter wave is going to be different this year, compared to last.  Mainly, the hallmark of the Delta variant in a half-vaccinated population is high hospitalization rate and low death rate.  Not a lot of deaths, arguably attributable to a high vaccination rate in the elderly.  But many more hospitalizations per case than we have seen in the past.

Even in a normal year, hospital occupancy rises somewhat in winter.  This year, a winter wave driven by the high-hospitalization Delta variant seems like a pretty clear collision course.  I think we’ll be returning to an era when your primary patriotic duty is not to be the person who fills the next hospital bed.

You’re going to be hearing people urging you to get your flu shot this year.  I’m certainly going to get one.  The flu shot is, at best, 60% effective against any infection.  But much like the COVID-19 vaccine, it’s better than that at preventing severe illness.  This is not going to be a good year to be hospitalized for a wintertime respiratory illness.

And for goodness sake, if you’re still using those 20-cent disposable blue masks, do yourself a favor, toss them in the trash, and buy some NIOSH-certified N95s while you can.  Consider that upgrade to be your patriotic duty.

Data source for this and other graphs of new case counts:  Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 8/31/2021, from”  The NY Times U.S. tracking page may be found at

Here are a two graphs showing that FL/LA/MS appear to have peaked, and are now being passed by other states where new case rates are still rising.

In the South Central region (which would include the Gulf Coast), it looks like nearly every state has peaked.  Or, at least, the contour of the the collection of states looks like a peak.  By contrast, with the exception of Missouri, it looks like every state in the Midwest and Mountain regions has rising rates.  Below, from top to bottom:  South Central, Midwest, Mountain.

Let me briefly remind you why that matters, on the graph below.  If you’ll study last year’s winter wave, those regions led it.  They started their rise, in earnest, in September, and peaked by Thanksgiving.  They were the bellwether.  By November, pretty much every region had sharply rising new-case rates.

It’s tough to focus on winter right now, but the timing of last year’s winter wave is a fact.  And tomorrow is the first of September.  Coincidentally, the graph above starts on 9/1/2020.   I’m betting we’ll have some sort of winter wave this year, and I’m betting that it’s going to stress out the U.S. hospital system pretty badly.  Ignoring that won’t make it go away.