Climate
The weather in San Francisco tends to be relatively mild year-round without the extreme fluctuations experienced in other parts of the country. Typically the best months of the year are April, May, June, September and October. These months tend to be warmer with sparkling clear days. San Francisco's summer climate is typically cool with early morning fog that burns off by mid-day. Summer evenings tend to be relatively cool. Winters are very mild compared to the rest of the United States, with several periods of temperate weather broken up by the occasional rain storm.

Casual wear is acceptable most of the time. Some establishments (nightclubs and bars) have a 'no jeans, no running shoes' policy. Certain dining rooms require men to wear jackets to dinner.

Credit Cards
Most credit cards are widely accepted throughout San Francisco. Bank machines can be found everywhere and debit cards are also widely used. If you are using a foreign card at a bank machine, your money will be disbursed in U.S. funds.

Currency
Financial institutions will provide a credible rate of exchange when switching your currency for U.S. dollars.

Electrical Current
110 Volts, 60 Cycles AC (same as Canada and Mexico)

Health Insurance
The United States has a very high quality of medical care. However, it is a private system and, as such, is very expensive by any standard. You should consider the purchase of your own health insurance a necessity. Even if you are covered by your home country's national health insurance system, your country will probably not pay all costs associated with health care in the U.S., so additional coverage is necessary.

Visitors taking medicine prescribed by a doctor should bring a copy of the prescription in case it needs to be renewed by a doctor in the U.S.

Liquor Laws
In the United States, all states require that you be 21 years of age or older to purchase and/or consume alcoholic beverages.

Public Holidays

Time Zones
The continental United States has four time zones: Eastern, Central (1 hour behind Eastern), Mountain (2 hours behind Eastern), and Pacific (3 hours behind Eastern). San Francisco is in the Pacific time zone.

Tipping
Tips or service charges are not usually added to a bill in the U.S. The exception to this is when a large group of approximately eight or more are dining together in a restaurant, in which case the establishment may state in advance that a gratuity of 15% will automatically be added to the bill.

In general, a tip of 15% of the sub-total (before taxes) is given. This applies to waiters, waitresses, barbers and hairdressers, taxi drivers, etc. At hotels, airports and railway stations, bellhops, doormen, redcaps (porters), etc. are generally paid $1-2 per item of luggage.

New Requirements for Travelers
As of January 23, 2007, travelers to and from Canada, Mexico, Central and South America, the Caribbean, and Bermuda will be required to have a passport or other secure, accepted document to enter or re-enter the United States. This requirement will apply to all air travel and will be extended to all land and sea border crossings sometime in June 2008.

For more information, visit the US Department of State's travel website.