Napa (CA) Climate by Month
Napa experiences great temperature shifts.
The city's weather can transition from warm days
to mild weather.
It receives mid-range precipitation levels.
Now, let’s break down all the climate details for a clearer picture.
Average day and night temperature
The climate in Napa is known for significant temperature differences throughout the year, making the weather dynamic. Average daytime temperatures range from a comfortable 30°C in September, the warmest time of the year, to a moderate 14°C during cooler months like January. At night, temperatures typically average around 4°C during these months.
The mean minimum and maximum temperatures throughout the year
Precipitation and rainy days
Generally, Napa receives mid-range precipitation levels, with 585 mm annually. Significant seasonal changes in precipitation occur throughout the year. During the wetter season, December receives high rainfall, averaging 120 mm of precipitation, recorded across 11 rainy days. In contrast, the drier season, July brings less rainfall, with 0.1 mm over 0 rainy days.The mean monthly precipitation over the year, including rain, hail and snow
The average number of days each month with precipitation
Sunshine over the year
Seasonal changes in sunshine hours are quite dramatic in Napa. While May receives considerable daily sunshine with up to 10.3 hours, December marks the darkest time of the year, where sunshine is scarce with only 5.3 hours of sunlight per day.Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
The best time of year to visit Napa in the United States of America
During the months of April, May and October you are most likely to experience good weather with pleasant average temperatures that fall between 20°C and 26°C.Other facts from our historical weather data:
Yes, the months of May, June, July, August and September are very dry.
September has an average maximum temperature of 30°C and is the warmest month of the year.
The coldest month is January with an average maximum temperature of 14°C.
December tops the wettest month list with 120 mm of rainfall.
July is the driest month with 0 mm of precipitation.
May is the sunniest month with an average of 310 hours of sunshine.
No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.
