The city's peak seasons generally coincide with two activities: the sessions of Congress and springtime, starting with the appearance of the cherry blossoms along the Potomac. Specifically, when Congress is "in," from about the second week in September until Thanksgiving, and again from about mid-January through June, hotels are full with guests whose business takes them to Capitol Hill or to conferences. Mid-March through June traditionally is the most frenzied season, when families and school groups descend upon the city to see the cherry blossoms and enjoy Washington's sensational spring. This is also a popular season for protest marches. Hotel rooms are at a premium and airfares tend to be higher.

If crowds turn you off, consider visiting Washington at the end of August/early September, when Congress is still "out," and families return home to get their children back to school, or between Thanksgiving and mid-January, when Congress leaves again and many people are ensconced in their own holiday-at-home celebrations. Hotel rates are cheapest at this time, too, and many hotels offer attractive packages.

If you're thinking of visiting in July and August, be forewarned: The weather is very hot and humid. Many of Washington's performance stages go dark in summer, although outdoor arenas and parks pick up some of the slack by featuring concerts, festivals, parades, and more. And, of course, Independence Day (July 4th) in the capital is a spectacular celebration.

The Weather

Check the Washington Post's website (www.washingtonpost.com) or the Washington, D.C. Convention and Tourism Corporation website (www.washington.org) for current and projected weather forecasts.

Season by season, here's what you can expect of the weather in Washington:

Fall: This is my favorite season. The weather is often warm during the day -- in fact, if you're here in early fall, it may seem entirely too warm. But it cools off, even getting a bit crisp, at night. All the greenery that Washington is famous for dons the brilliant colors of fall foliage, and the stream of tourists tapers off.

Winter: People like to say that Washington winters are mild -- and sure, if you're from Minnesota, you'll find Washington warmer, no doubt. But D.C. winters can be unpredictable: bitter cold one day, an ice storm the next, followed by a couple of days of sun and higher temperatures. Pack for all possibilities.

Spring: Early spring weather tends to be colder than most people expect. Cherry blossom season, late March to early April, can be iffy -- and very often rainy. Then, as April slips into May, the weather usually mellows, and people's moods with it. Late spring is especially lovely, with mild temperatures and intermittent days of sunshine, flowers, and trees colorfully erupting in gardens and parks all over town. Washingtonians, restless after having been cooped inside for months, sweep outdoors to stroll the National Mall, sit on a park bench, or laze away an afternoon at an outdoor cafe. Spring is a great time to enjoy D.C.'s outdoor attractions. But during this season, the city is also at its most crowded with visitors and school groups.

Summer: Throngs remain in summer, and anyone who's ever spent August in D.C. will tell you how hot and steamy it can be. Though the buildings are air-conditioned, many of Washington's attractions, like the memorials, monuments, and organized tours, are outdoors and unshaded, and the heat can quickly get to you. Make sure you stop frequently for drinks (vendors are everywhere), and wear a hat and/or sunscreen.