San Diego enjoys a hot-summer Mediterranean climate (Köppen Csa), but it is notably more arid than typical Mediterranean zones, with the coastal airport area even straddling the borderline between semi-arid and arid classifications. Temperatures are remarkably mild year-round, averaging from 57.3°F (14.1°C) in January to 72°F (22°C) in August, with only about 25 days annually exceeding 80°F (27°C), though the record high is a scorching 111°F (44°C) set on September 26, 1963 (tied in 2010), and the record low is 25°F (-4°C) from January 7, 1913. A defining feature is the marine layer, which brings morning fog and cool, cloudy conditions, famously nicknamed "May gray" and "June gloom" during the late spring and early summer. Occasional Santa Ana winds from inland deserts bring hot, dry air, making October the peak of fire season despite the generally mild averages. Precipitation is scarce, averaging under 12 inches (30 cm) annually, heavily concentrated from December to March, and is highly variable, leading to both droughts and floods; notably, San Diego receives more tropical storm remnants than anywhere else in California, including the 1858 hurricane and Hurricane Hilary in 2023. While the coast is dry, rainfall increases dramatically inland—El Cajon gets over 20 inches and Palomar Mountain over 40 inches per year—and the city enjoys about 146 fully sunny days annually.