Depends on what you define as a warm spell. I know what you mean, that people will attribute a week or two that is well above average to global warming, which is definitely asinine. But if the warm spell we’re talking about is many locations having 10 or 11 months per year with above normal temperatures, year after year after year, then it gets a little murkier.
Edit: this is way off topic and we’re not going down this road in yet another thread. Agree to disagree.