It was a beautiful summer day when I flew in the N3N. I honestly don't recall.
To be fair, I have not yet flown in a Stearman, so, no way to make a fair comparison.
That being said, I've flown my Tiger Moth down in the low 40's.
Very important to dress properly (basically, everything you own

)
Gloves are key. The throttle gets cold and steals the heat from a bare hand.
The rear pit of the Tiger is definitely draftier than the front.
Andy