Optimal period for the East Coast is shoulder season: April-May-June (spring) and September-October (autumn). Perfect temperatures (15-23°C), often clear sky, urban parks at their peak (Central Park, Boston Common, National Mall), reasonable airfare (Paris-NYC €450-700 return), moderate crowds outside key events.
New England foliage (mid-September to mid-October) is one of America's most beautiful natural spectacles — Vermont, New Hampshire, Maine, Berkshires in red-orange-gold. Optimal peak around October 5-15 for northern zones (Vermont, NH, Maine), October 10-20 for Berkshires and northern New York. Book 3-6 months ahead. Washington D.C. cherry blossoms (late March-early April, Cherry Blossom Festival, gifted by Japan in 1912) also draw millions.
Summer (July-August) brings crushing heat and humidity — NYC, Washington 30-35°C with 75-85% humidity, 40°C feels-like, A/C essential. Boston slightly cooler (28-32°C) thanks to ocean breeze. Peak airfare (€700-1,100 return), saturated Times Square, 2-3h Statue of Liberty wait. Upsides: many festivals (Central Park SummerStage, Newport Folk Festival, Tanglewood Berkshires), Cape Cod / Hamptons / Outer Banks beaches in full swing, long evenings.
Winter (November-March) is freezing but magical. New York in December is a must — Rockefeller Center tree, Christmas markets, Bryant Park ice skating, Macy's windows, Broadway musicals festive season. But -5 to 5°C, icy winds, possible blizzards (Sandy 2012, 2015 blizzard, paralyse transport), short nights (4:30pm sunset in December). Stratospheric Christmas/New Year fares (Manhattan hotels €400-800/night). Prefer January-February-March for best deals.
Read also
- New York City — Manhattan, Times Square, Central Park, Brooklyn: the world's most iconic metropolis.
- United States — Complete country-continent guide: ESTA visa, currency, regions, best time.
- California — The West Coast alternative: Los Angeles, San Francisco, Yosemite.
- Florida — The beach and Disney option: Miami, Orlando, Keys.