Napa (CA) Temperatures: Monthly Averages and Year-Round Insights
On this page, we’ll explore Napa’s temperature statistics in detail, including day and night variations and monthly averages. We’ll also compare the annual temperature to other cities in the United States of America.
Monthly Temperature Averages
Depending on the time of the year, temperatures range from comfortable to mild in Napa. Average maximum 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, minimum temperatures typically average around 4°C during these months.
The chart below illustrates the average maximum day and minimum night temperatures in Napa by month:
The early hours of 4 AM to 6 AM often see the lowest temperatures, while 3 PM marks the peak of the day’s heat as the sun’s impact is strongest. September, the city’s warmest month, boasts 275 hours of sunshine.
The chart below shows the average temperature throughout the year:
January, the city’s coldest month, receives about 91 mm of rainfall spread over roughly 9 days. For more information, please visit our Napa Precipitation page.
Annual Temperatures in the United States of America Compared
The map below shows the annual temperature across the United States of America. You can also select the different months in case you are interested in a specific month.
very warm
warm
pleasant
moderate
cold
very cold
Napa Temperatures Compared World Wide
Napa’s average annual maximum temperature is 23°C. Let’s compare this with some popular tourist destinations:
Seville, Spain, stands out with its warm Mediterranean climate and an average annual temperature of 23°C.
Meanwhile, Queenstown, New Zealand, the average annual temperature is significantly lower at 10°C, with mild summers and cold winters.
Chicago, USA, has a significant seasonal range, with an average annual temperature of 15°C.
Perth, Australia, experiences a Mediterranean climate, with a pleasant average temperature of 25°C.
How are these Temperatures Measured?
Generally, temperature data depicting climate is usually given over a 30-year average in order to reduce short-term fluctuations and reveal better long-term trends in climate conditions.
This temperature data is taken from land-based thermometers, ocean buoys, ships, and satellites. These measurements are transmitted to weather stations and climate centers around the globe where they are processed, averaged, and analyzed in order to monitor the trends and create climate models.
Sea vs. Land Temperatures
The influence of nearby oceans or large water bodies significantly affects local temperatures:
- Ocean Influence: Coastal regions tend to have more stable temperatures, as large bodies of water absorb and release heat slowly. This often results in milder winters and cooler summers compared to inland areas.
- Continental Climates: Landmasses well away from large bodies of water tend to show greater extremes in temperature, having hotter summers and colder winters because of the absence of water as a moderating influence.
For more detailed information about Napa’s weather, including monthly rainfall, sunshine hours, and humidity levels, visit our Napa climate page.
Current temperature in Napa (CA)
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overcast and heavy rain
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