Climate in San Diego

If you're coming to San Diego expecting sunny weather, avoid coming in May or June, when San Diego is covered in clouds most days, a phenomenon referred to by the locals as "May Grey" or "June Gloom". September is usually the hottest month of the year in the daytime. Mid-September through October are labeled as the most at-risk months for wildfires, because of the long absence of any substantial rainfall. Along the beach during the warmer half of the year, it can get surprisingly cool after dark, even when it's not too cold a short distance inland. The months of March and April typically see the strongest winds. Along the coast, fog is most common September through April; it is not uncommon to experience 3-7 foggy days per month.

During the late summer and fall there is a reversal of the usual climate conditions, when hot, dry air blows from the desert to the coast. These winds are called the Santa Ana winds. Milder Santa Ana winds can result in excellent dry air conditions, but powerful ones can last days on end, significantly raising temperatures, creating tremendous fire danger, and making the outdoors unpleasant