San Bruno

What is the climate like in San Bruno?

The best time to visit San Bruno is typically April – October, with trip comfort peaking in September (8.4/10). San Bruno is warmest in September, when daily highs average 69°F (20°C), and coolest in December, when lows fall to about 48°F (9°C). The wettest month is typically January and the driest is August; the year sees roughly 23 in (576 mm) of precipitation.

• Best time to visitApril – October — comfort peaks in September (8.4/10)
• Warmest monthSeptember — average high 69°F (20°C)
• Coolest monthDecember — average low 48°F (9°C)
• Wettest monthJanuary (4.7 in (120 mm))
• Driest monthAugust (0.1 in (3 mm))
• Annual precipitation23 in (576 mm)
• Based on2016-2025 daily ERA5 reanalysis data (10-year normals)
• Records fromSan Francisco Intl AP, 4 km away (1945-2026)