Generally speaking (repeat, GENERALLY) Columbus Day week is the time
for the New England Fall foliage display, depending upon how far north
or south you are (i.e., it starts in Northern New Hampshire and spreads
southward as the days/weeks go by) and on the particular conditions
that year.

If you check the web, there are sites about the Fall foliage.  Try
Googling "fall new england foliage" or some such phrase.

The peak does vary from year to year.

Harvey Chao