San Francisco has a microclimate that surprises first-time visitors. The warmest months are September and October, when the famous Bay Area fog retreats and temperatures reach 18C to 22C. This is the window for visiting Alcatraz, cycling across the Golden Gate Bridge, and exploring the Marin Headlands without thick morning clouds. June is the most famous fog month, with Karl the Fog (as locals call it) regularly obscuring the Golden Gate and cooling temperatures to 14C to 17C. Summer is actually cooler than spring in San Francisco due to the cold California Current offshore. Carry a jacket in any month. April and May have mild temperatures and lower rainfall after the winter wet season. The Cherry Blossom Festival in Japantown (April) and Bay to Breakers foot race in May are popular spring events. December through February is the rainy season, with consistent rain in January. The city's indoor culture of world-class restaurants, the Ferry Building Marketplace, and the SFMOMA are best enjoyed in winter.