The month in detail
What to expect in August
In the height of summer, Napa Valley sees high temperatures (91°F). Heat is a factor for outdoor activities. Rain is virtually absent (1% of days) — ideal for planning without a backup. A good balance between weather and crowds, even if June (9.3/10) remains theoretically better.
August ranks 4 out of 12 months in Napa Valley. Compared to July: −0.6h of sun per day.
This month's conditions
What it's like in August
UV index
8 · high
sunscreen and hat advised
Feels like
comfortable
11°
Daylight
13.5h of daylight
Air quality
good
AQI 24
Compare
Is August the right month?
The best month in Napa Valley is June (9.3/10), 0.7 pt higher than August.
Book
Plan your trip
Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.
Stay
Hotels & rentals · Napa Valley
Expedia →
Activities
Tours, tickets, experiences
See ↓
Flights
Multi-airline comparator
Kiwi →
🎟️ Activities & tours · Napa Valley
GetYourGuide selection · free cancellation
Practical info
What you need to know before you go
Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a city break.
Country · United States
🗣️LanguageEnglish
💶CurrencyUS Dollar ($)
🚗DrivingRight-hand
🛡️Safety ⓘVery safe · 1/5
💰Cost of living ⓘExpensive · 4/5
🌡️ Climate
🌍Climate typeTemperate
📈Climate trend ⓘStable
🔥Hottest monthJuly · 91°F
❄️Coolest monthJanuary · 55°F
🌧️Rainiest month ⓘJanuary · 28%
🏛️ City break
📅Tourist peak seasonJune → August
☔Indoor sights ⓘYear-round
🚇Public transportGood
Explore
Other destinations in August
If August doesn't convince you for this destination, compare with others.
Location
Where is Napa Valley ?
Global position + regional geographic context.
🌍 World
🔍 Geographic context
United StatesTemperate climate with a 9.3 → 4.2 gap between best and worst month. 10 years of ERA5 data to choose by project.
38.50°N · 122.27°W
Questions
Frequently asked questions
What is the best time to visit Napa Valley?
June is the best month with 86°F highs, 55°F lows, 10.1h of sunshine and 2.0% rainy days. The months of June & September offer comparable conditions.
How many hours of sunshine does Napa Valley get in June?
Napa Valley averages 10.1 sunshine hours per day in June. It is the sunniest month with a climate score of 9.1/10.
What is the rainiest month in Napa Valley?
January is the most unfavourable month with January has the lowest climate score of the year and the lowest climate score of the year.
What are the temperatures at night in Napa Valley in June?
In June, overnight lows reach 55°F, while afternoon highs average 86°F.
Is Napa Valley good in winter?
In winter (December-February), Napa Valley scores 4.1/10 on average — Difficult period — prefer the peak season.. The best month overall remains June with a score of 9.1/10.
When should you avoid Napa Valley?
January is the most difficult month to visit Napa Valley, with January has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.
Do you need sun protection in Napa Valley in August?
The average UV index reaches 8 in August in Napa Valley (high), with about 13.5h of daylight. Sunscreen and hat advised.