The weather in San Diego is sunny and mild all year round, with little variation in temperature between summer and winter. Occasional heat spells are caused by the hot Santa Ana winds blowing in from the desert, otherwise temperatures range between a low of 57°F (14°C) and average high of 72°F (22°C). May and June are prone to fog. Rainfall is low, most of it falling between December and March.

Getting around San Diego is relatively easy without a car, with three types of public transport servicing the city. Buses and the Trolley light rail cover the city, but service generally stops around midnight. The Trolley is the best way to get to the border with Mexico for trips to Tijuana. Passes are available from the Transit Store for both bus and trolley fares; it also provides timetables and route information. A Coaster train service operates during morning and evening rush hours, linking downtown with the outlying northern coastal communities as well as providing four services on Saturdays. The Coronado Ferry as well as a water taxi service shuttle passengers between the city and Coronado Island (also connected to the mainland by bridge). Privately-owned Old Town Trolley Tours offers hop-on, hop-off narrated tours of places of interest for tourists, though this option is a bit more expensive than the public Trolley. Taxis must be ordered by phone, but waiting times can be long. Cycling is a popular way to get around San Diego, and there are numerous bike hire shops and many designated bicycle lanes. Some bus routes, the trolleys and the Coronado Ferry offer free passage of bicycles, allowing people to get to an area by public transport and then explore from there. Although possible to get around using public transport, many people prefer to rent a car, especially as there is no public transport late at night, and some areas are easier and quicker to get to by car. The city is easy to navigate with well laid out highways, and parking meters are plentiful. Car rental agencies require a credit card or cash deposit and a valid driver's license, and the minimum age is usually 25 years.

English is the most common language but Spanish is often spoken in south-western states.

The US Dollar (USD) is the unit of currency and is divided into 100 cents. Only major banks exchange foreign currency. ATMs are widespread and credit cards and travellers cheques are widely accepted. Travellers cheques should be taken in US Dollars to avoid hassles. Banking hours are Monday to Friday 9am to 3pm.