A/c in the context of the article?
* https://en.wikipedia.org/wiki/Humid_continental_climate
However, the general point stands in mostly-cold zones: it is possible to control humidity independently of temperature.
Also, most people want good indoor air quality, so bringing in filtered outside air, and tempering it with exhausted stale air is becoming more common (and is part of the building code in many regions):
* https://www.ecohome.net/guides/2276/choosing-between-an-hrv-...
* https://www.venmar.ca/23-detail-faq-en-what-is-the-differenc...
And that venting could help control humidity as well.