Everybody began to look upon the danger as good as over

From A Journal of the Plague Year by Daniel Defoe.  

However, all this went off again, and the weather proving cold, and the frost, which began in December, still continuing very severe even till near the end of February, attended with sharp though moderate winds, the bills decreased again, and the city grew healthy, and everybody began to look upon the danger as good as over; only that still the burials in St Giles’s continued high. From the beginning of April especially they stood at twenty-five each week, till the week from the 18th to the 25th, when there was buried in St Giles’s parish thirty, whereof two of the plague and eight of the spotted-fever, which was looked upon as the same thing; likewise the number that died of the spotted-fever in the whole increased, being eight the week before, and twelve the week above-named.

This alarmed us all again, and terrible apprehensions were among the people, especially the weather being now changed and growing warm, and the summer being at hand. However, the next week there seemed to be some hopes again; the bills were low, the number of the dead in all was but 388, there was none of the plague, and but four of the spotted-fever.

But the following week it returned again, and the distemper was spread into two or three other parishes, viz., St Andrew’s, Holborn; St Clement Danes; and, to the great affliction of the city, one died within the walls, in the parish of St Mary Woolchurch, that is to say, in Bearbinder Lane, near Stocks Market; in all there were nine of the plague and six of the spotted-fever. 

Parallels to today:

In most quarters, it has been anticipated that there would be a cyclicality to Covid-19 with an anticipation that it would synchronize to the seasons with onsets in fall and winter.  In practice, we are seeing intermittence without really seeing cyclicality yet. 

We don't know why some countries are not hid till many months after others.  Some regions of the US are on their second wave while others appear on a third wave for reasons not known with confidence.   

It is not that there is not cyclicality or that that cyclicality won't be tied to the seasons.  We just aren't seeing it yet with any predictability.  

This uncertainty has colored (along with sheer partisan bias) the coverage of state re-openings.  Some states reopening early and with great confidence, others later with great trepidation.  We don't know yet.