October is the first month that comes to mind when you think of peak fall colors, but it really depends on what part of the country you live in.
Here in North Carolina, peak fall colors start around mid October in the mountains, and work their way into our area (Raleigh, Durham, Chapel Hill, NC) a few weeks later. Which means those radiant blazes of scarlet, yellow and orange don't really show up until November. In fact the most spectacular colors for autumn for our area often occur between November 7th and November 15th.
So if you are planning a wedding in the Raleigh, Durham, or Chapel Hill area, and you really want those fabulous
fall colors, think November!