My boss, out of the blue yesterday, asked me if it ever gets too hot for me to play. I've played in 112* in Phoenix before. Fairly frequently play in mid-90s in NY. Those days are worse than the 112 in Phoenix. I said no. But I'll play in anything. I've played in sleet, snow, hail (one time it hailed on us while blowing a steady 45mph gusting to 55mph - as verified by an anemometer in the clubhouse), torrential rain, high winds, cold, hot, you name it.
Lightning will get me off the golf course though. I'm not an idiot (well, not that much of one anyway).
I'm an all weather golfer. Luckily in my part of the Bay Area, it never get's much hotter than mid-70s, and the only humidity fog, so I don't have to deal with hot and humid weather.
Most of the year I only have time to play once a week, and it's my weekly psychological break from the daily experience of work/parenthood so I hate to miss it. The only thing that really gives me pause is high winds, because my home course has tons of trees, and quite a few are diseased/dying.
Often times when I am out playing and the weather is really shitty I will momentarily question my decision to play, but I rarely regret it.
I can't really vote. I'll play in 50° if it's even a little sunny and not pouring. I'll play in 90°.
I generally won't play when it's pouring, ridiculously windy, or > 100° or below about 40°.