July in San Mateo averages a daily high of 22°C with nights around 13.2°C. Rain is rare — about 0 wet days and 0mm across the month. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit San Mateo is May–October.
Based on SAN FRANCISCO INTERNATIONAL AIRPORT, CA US (7.2km), 1995–2024. 29 years of July data.