Cabrillo National Monument enjoys a Mediterranean climate characterized by warm, dry summers and cool, mild winters. Weather data is recorded for San Diego at Lindbergh Field (the airport) which is directly across the bay from the monument. The average annual temperature is 64 degrees and the average annual rainfall is a scant 9.5 inches. Rainfall is concentrated in the winter, from November to April, but the amount can drastically change year to year, from 3.4 inches to 19.4 inches. This variability in rainfall causes certain types of plants to thrive one year and barely survive another. Nature makes up for this lack of rain when cold air from the ocean meets the balmy air on the land and dense fogs roll in. The fog adds moisture to allow species requiring more water to coexist with the desert plants and animals. The ocean also keeps air temperatures mild year-round, which allows heat-loving cactus to grow next to evergreen shrubs common in cooler climates, salamanders to walk past sunning desert snakes, and mosses to grow in the cool shade, a stone’s throw from where parched lichen cling to dry, hot boulders.