Some estimates put the count at 2.8 million visitors who crowd New England during the confines of a fall-foliage time span best counted in weeks.
When and where the leaves change is up to the weather, the soil, the sunlight, the elevation, the latitude and the trees themselves -- each species operates on a different biological clock. That's why fall-foliage hot lines are useful in planning trips.
But there's a caveat: Leaf-peeping is popular and requires booking reservations weeks and perhaps months in advance; and you won't know the very best time to go until it's time to go. For New England, it's fairly safe, season-wise, to plan something between mid-September and mid-October (that's when the big tour companies schedule their trips). These numbers might help; but some won't be in operation, or won't provide foliage information, until the season gets started:
Connecticut, (800) 282-6863; Maine, (800) 533-9595; Massachusetts, (800) 227-6277 or (800) 447-6277; New Hampshire, (800) 258-3608; New York, (800) CALL-NYS; Rhode Island, (800) 556-2484, and Vermont, (800) 837-6668.