Of course weather plays a role. It's not the only one, however.
And Australia celebrates things like Christmas/Hanukkah/etc., New Years, and Australia Day all in a roughly month-long time frame, with all attendant travel and group gathering, correct?
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The human race still tends to fail upward over time. Of course, it only takes one civilization ending catastrophe to wipe us out, so we'd rather maintain that 100% record.
Even most of the stupid people will have immune systems more capable of fighting off subsequent COVID infections by this point. Their open flouting of danger won't have as much of an impact going forward...
....at least for this specific virus.