Collocations for temperament - noun

fiery, violent, volatile
fragile (esp. BrE), high-strung (AmE), highly strung (BrE), nervous (esp. BrE)
cool, even, good, sanguine (BrE), unflappable (esp. BrE)
docile (esp. BrE)
sunny
difficult
right
He doesn't have the right temperament for the job.

romantic
artistic, judicial (AmE), scientific, etc.

have

by temperament, in temperament
She was fiery by temperament.