We had a week or so of that at the beginning of January here. In fact, I don't think it got above freezing here from Christmas eve until January 4th or so. High temperatures hovered around -3C most of those days, with lows around -12.
"A couple of days with 30+ C"? We get that most days between mid-June and early September here.
Lightweight.
(Of course, I do live in the barren desert, so....)
The first time I tried to bake bread, I added water that was too hot and killed the yeast. The resulting loaf (charitably speaking) was very high density.