Where does “extemporally” come from?

extemporally (English) comes from English extemporal, from Latin extemporalis, from Latin -ālis, from Proto-Italic -ālis.

extemporally (English): In an extemporal manner

Definitions

Step	Language	Word	Meaning
1	English	extemporal	Extemporaneous
2	Latin	extemporalis	unpremeditated; spontaneous
3	Latin	-ālis	—
4	Proto-Italic	-ālis	—

extemporally — Etymology, Origin & Word History | Etymology Explorer