Warm
Average highs sit around 27°C, giving warm days by monthly-average standards.
Weather Guide
Napa, California, United States Average Monthly Weather
Weather score47Mixed annual avg
Best months: July, August, June
Across the year, average daytime temperatures are around 21°C, sunshine averages 8.5h per day, and rainfall totals about 807mm. Sea temperatures average 12°C across the year.
Annual weather
Annual averages
Temp
21°C
Rain
807mm
Annual total
Sun
8.5h
Sea
12°C
Weather score
47
Mixed avg
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 3mm, which is relatively low for holiday planning.
Bright
Sunshine averages 10h per day, so bright days are a strong part of the month.
Cool sea
Sea temperatures average 12°C, so the water can feel cool.
Map
Weather map
Compare Napa, California, United States with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
August27°C average high
August is one of Napa's warmest months, with daytime heat above the yearly average.
Warmest monthsJune to September
This stretch sets the upper range for average daytime heat.
Rain
August3mm average rain
August is one of Napa's driest months, making outdoor days easier to plan than in wetter parts of the year.
Driest monthsApril to October
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
August10 hours average sun
August is brighter than Napa's yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsApril to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
August12°C average sea
August sits in the warmer sea-temperature season, usually making swimming easier to enjoy.
Warmest seaJanuary and August to December
Sea temperatures are usually near 12°C in this stretch, so swimming comfort is at its strongest.
Weather score
August69 weather score
August is one of Napa's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsMay to September
These months have the strongest weather score in the monthly averages.
