Collocations for autumn - noun

last, this past (esp. AmE)
the following, next, this, this coming
early, late
wet

weather
sun, sunlight, sunshine
frost, rain
gale, wind
landscape, sky
colours/colors
Now is the time when the autumn colours/colors are at their best.

leaf
the sound of autumn leaves rustling

equinox
term (BrE)
classes to be held for schoolchildren during the autumn term

collection, exhibition
their autumn collection of dresses