Napa Weather in September

Napa in September sees high temperatures, with highs around 30°C (86°F) and overnight lows of 12°C (54°F). With just 3.8 mm (0.1 in) of rainfall on average, rain is rarely an issue.

Rainfall in Napa in September

Expect around a single day of rain based on historical data, with 3.8 mm (0.1 in) average. If rain does fall, it tends to be very light and barely worth getting out an umbrella for.

Temperature in Napa in September

Napa in September has excellent weather. Days reach 30°C (86°F) and nights cool to 12°C (54°F). Overall, the month follows a fairly predictable daily temperature pattern. Nights drop to around 12°C (54°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable. On average, this month sees the highest temperatures of the year. Worth packing a few lighter outfits.

Sunshine in Napa in September

The days are predominantly sunny, with an estimated total of around 275 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.

If you prefer enjoying temperate temperatures and rain-free days, April, May, June, July, August and October typically offer 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.