Except for the windy, chilly winter months, Shanghai teems with tourists and business travelers, most notably May through October. July and August are unpleasantly hot and humid as a rule; locals often sleep on cots on the sidewalks to escape the pent-up heat of the day in their small apartments. Shanghai's busiest tourist periods coincide with its mildest weather in the spring and fall. September and October are really the ideal times to visit, but they're also popular times for meetings and conventions, leading to high hotel occupancy and uncompetitive room rates. To avoid the big crowds and still enjoy decent weather, the ideal time to visit is in late March or late October/early November. Besides the climate, the other major consideration in the timing of your visit should be the domestic Chinese travel season.
Climate-- Shanghai, located on the 31st parallel north, has a climate comparable to that of the southeastern coast of the United States, except that Shanghai's summer is hotter. Spring, from mid-March to mid-May, is mild but rainy. Summer, from mid-May to mid-September, is oppressively hot and humid. Winter, from mid-November to mid-March, is damp and chilly, but there is seldom snow and the daytime temperatures are usually above freezing. Autumn (Sept-Oct) is the most comfortable season, being neither too hot nor too rainy, but typhoon-propelled rains can strike in September.
Holidays-- National holidays observed in Shanghai with days off includeNew Year's Day(Jan 1),Spring Festival/Chinese New Year(first day of the lunar calendar: Feb 18, 2007; Feb 7, 2008, and January 26, 2009),Labor Day(May 1), andNational Day(Oct 1). Domestic travel peaks during these last three holidays.
Spring Festival,the Chinese New Year, is the most important holiday. Officially, it is a 5-day national holiday (expanded to 7 days when you include the weekend), meaning that on the first 3 days, banks, offices, and many workplaces are closed. In reality, the effects of this holiday are felt from 2 weeks before the date until 2 weeks after, as Chinese travel to and from their hometowns, which may be very far from their place of work. The 15th day of the New Year is marked by the Lantern Festival celebrations.
The other two busy periods for domestic travel are the weeks surroundingLabor Day(May 1), andNational Day(Oct 1). Both holidays have been expanded to 7 days (including 1 weekend) to encourage Chinese to travel and shop. During these times, hundreds of millions of
Chinese are on the move, especially at the beginning and end of the 7 days, taxing all transportation systems to the extreme. While offices, banks, smaller restaurants, and some sights may be closed for part of each holiday period, you will find in Shanghai that hotels that normally cater to business travelers will offer significant discounts during those times.