Oulu proves that temperature is a surmountable obstacle. I think the parent comment was right in that biking is very difficult to sell when those circumstances aren't right, even though some cities might overcome anything with sufficient bike culture and good infrastructure.
On the other end of the spectrum, and unanserwed in the article here—Sevilla might be a great place to study the effect of heat.
https://usa.streetsblog.org/2020/10/13/best-practices-how-se...