How long will you be on vacation? How far along the coast do you plan on going and where do you plan to stop, Maine is a long coastline.
Timimg is everything and there's no way to know for sure ahead of time. The White Mtn region is famous for fall foliage, but the difference from one weekend to the next can be huge. You'll want to pay close attention to local TV coverage and websites to know where to go. Colors will turn first at higher elevations and then gradually work down into the valleys.
No one seems to recommend a truly beautiful part of New Hampshire and that is the southwest corner. Not only is it convenient to western Mass and southern Vermont, both beautiful areas, it offers gorgeous foliage, quaint villages, apple orchards, covered bridges, great restaurants and places to stay. Because of its location it makes a great place to plan day trips from also. Foliage can be tracked at the state web site, www.visitnh.gov, with daily updates from volunteer leaf peeper reporters. Early Oct is usually the start of peak foliage.
I would agree with Weaver, but late Sept/early Oct is more likely to be full color in the north. Question is, are you flying into Boston and heading north to Bar Harbor, or into Bangor, which is close to BH, and heading south? If you fly into Boston, I would recommend heading up the coast. Ogunquit will be along the way, and a very nice place for an overnight, if that is what you are thinking.
From BH, your may want to head across Rte 2 through Maine, across the White Mountains of NH, and across VT. This is one gorgeous and rural drive, and should be in beautiful color about that time. From Burlington or Montpelier VT you will have a straight shot on I-89 to I-93 back down to Boston, if that is where your flight is. About 3+ hours straight shot.
You would see some color in northern NH and VT during the last week or so of September, but the peak colors don't arrive until October. The higher mountain elevations are usually at peak during the first week of the month, and peak color in the lower elevations around the mountains typically follows in the second week. By Columbus Day weekend, much of NH and VT is at high or peak color. This great color usually lasts for another week or so before winding down, with only coastal areas experiencing true peak colors during the last week of the month.
Of course, every year is a little different, so these are just general guidelines based on personal observations. This site can be useful in getting an idea of when to expect peak foliage: foliagenetwork.com/index.php…
The White Mountains of NH are definitely a must-see. There are several scenic drives, including the Kancamagus Highway between Conway and Lincoln, I-93 from Lincoln through Franconia Notch State Park, Route 302 through Crawford Notch State Park, the Mt. Washington Auto Road, and Bear Notch Rd. Cathedral Ledge and Echo Lake in North Conway are also gorgeous in the fall. These drives can be put together to form a loop.
Just south of the White Mountains, the Lakes Region also makes for some great fall drives. My favorite village in the state is Sandwich, and a nice drive is Route 113 between Sandwich and Holderness, with a stop at the Rattlesnake Mtn. trailhead for a quick hike that gives you an incredible view of Squam Lake. Also of interest in the area is the Castle in the Clouds in Moultonborough and the lakeside towns of Meredith and Wolfeboro. If the foliage conditions are right, a drive around Lake Winnipesaukee is great.
As for Vermont, it's hard to find a country road that *isn't* scenic in the fall. You should plan on a stop at Quechee Gorge and Woodstock. Another great drive is Route 7A between Manchester and Bennington, taking the Mount Equinox Skyline Drive for incredible vistas. The northern part of the state provides an endless supply of amazingly picturesque drives, but I can't provide any specific recommendations - they're all great.
Are you confused yet? All of the advice given is great and you really can't go wrong. It is just a matter of how much driving you want to do vs how much you want to get out of the car experience the wonderful views. For instance, a great hike which ends with great views is Mt Chocorua which is at the southern end of the MW Valley. mountainsummits.com/mountains/…chocorua.htm
Viewing the foliage is so much nicer when it is not blurry as you drive by. The Mt Equinox suggestion is also great in Vt for wonderful views. Stop for a drink in the Equinox hotel tavern.
I have a feeling that part of your decision will be based on how far north you want to go with the Maine
Coast. If it is just southern maine, then you could fly into Providence, RI spend time in Boston (45 minuts away), drive up the coast to maine, across the White Mtn, over to Vt and down the spine of Vt and then leave from Albany. This depends on SWA being available to you.
Just a thought Happy planning
In New Hampshire's White Mountains, you should check out the Bear Mountain Lodge in Bethlehem. It's a beautiful new log cabin that's set back on the property with great views of Mt. Washington. It's close to Franconia Notch, the Flume, Cannon Mtn, etc. and a short drive to the Cog Railway station. There are great restaurants in the area, Cold Mountain Cafe and Rosa Flamingo's as well as Timbur Alley and Baliwick's in Littleton.
We stayed their last year and loved it. The innkeepers work very hard to make everyone have a great stay. Michael is funny and has tons of great suggestions for hikes and Carol's breakfasts were excellent and filling. We loved the raspberry muffins and french toast one morning.
We are already planning a trip back this year and can't wait. We've recommended them to friends and family and a couple have gone themselves and been very happy. Check their reviews to see what others are saying. You wouldn't be disappointed.
I am not really sure how to advise you if you are going up to Arcadia. If you post on the Maine forums, maybe there are folks who can help with routes across the state. Seems that since you are that far north, you should head across to NH, VT and back down to Boston. You should mapquest the trip so you can see how much driving you will be doing.