I want to take a Metro North train north along the Hudson River from New York City, about 1-2 hours travel, maybe Peekskill. When would be the best time this year?
Foliage is late this year in this region. Normally you would expect peak foliage in mid-October, but we're still seeing a lot of green here currently. Based on current levels, I would expect to see peak color during the first two weeks in November.
If foliage is your main concern, I would consider traveling a little further north than Peekskill. You'll be getting better scenery if you stay on Metro-North until you get up to the Poughkeepsie region. Even if you don't feel like renting a car, taking the Walkway Over the Hudson to the west side of the river will put you right at the foothills of the Catskills.