The town of Antofagasta has a cold desert climate with abundant sunshine and strong maritime influence.
The marked aridity and water scarcity are regulated by the Humboldt Current, addition to the high humidity and morning fog known as “Camanchaca”. Furthermore, the Pacific anticyclone generates winds from the south and southwest.
The average annual temperature is 16.8 °C (62.2 °F). The average daily low temperature in the warmest month, January, is 17.5 °C (63.5 °F) while the average daily high temperature is 23.2 °C (73.8 °F). The coldest month, July, sees an average low temperature of 11.8 °C (53.2 °F) and an average high temperature of 16.5 °C (61.7 °F). The highest temperature recorded is 30.0 °C (86.0 °F) in January 1998 and the lowest recorded is 3.0 °C (37.4 °F) in September 1978.
The Atacama Desert coast is subject to a climate of extreme aridity, and therefore generates a low average annual rainfall of 3.4 mm (0.13 in) (1970–2000), and the Town of Antofagasta itself receives an annual average of less than 0.1 mm (0.00 in) of rainfall per year, earning it the record as the world’s driest town. However, the sporadic occurrence of heavy rainfall, together with the geomorphologic situation of the city, make it susceptible to be affected by mud flows and landslides. Between 1916 and 1999, the city was affected by floods or landslides on seven occasions: 1925, 1930, twice in 1940, 1982, 1987 and 1991, of which the most important episodes in 1940 and 1991.