August in South San Francisco averages a daily high of 22.6°C with nights around 13.8°C. Rain is rare — about 0.4 wet days and 0.7mm across the month. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit South San Francisco is May–October.
Based on SAN FRANCISCO INTERNATIONAL AIRPORT, CA US (5.4km), 1995–2024. 30 years of August data.