San Bernardino Weather in September

Thinking of visiting San Bernardino in September? Expect moderate temperatures reaching 14°C (57°F) during the day, dropping to 4°C (39°F) at night, and note that quite a bit of rainfall is likely.

Rainfall in San Bernardino in September

Historically, September sees about 15 days of rain, with a monthly average of 146 mm (5.7 in). Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.

Temperature in San Bernardino in September

Expect highs of 14°C (57°F) in San Bernardino in September, with nights dropping to around 4°C (39°F). A light jacket or extra layer can be useful, especially outside the warmest hours of the day. At 4°C (39°F) overnight, it gets properly cold after dark. On the bright side, cold nights tend to make for excellent sleeping conditions.

Sunshine in San Bernardino in September

The month experiences a moderate amount of sunlight, with 156 hours of sunshine. This provides a nice balance between sunshine and clouds.

For San Bernardino itself, July and August generally stand out with the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.