Napa (CA) monthly weather averages

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at Napa

Napa average temperature chart (Celsius) Napa average temperature chart (Fahrenheit)
Average monthly temperatures in Napa (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 12.6 15.6 16.9 19.4 22.6 25.9 27.7 27.5 26.4 23.3 16.8 12.7
°F 54.7 60.1 62.5 67 72.6 78.6 81.8 81.5 79.6 74 62.3 54.8

Please note: these are the average peak daytime temperatures (usually around mid-afternoon) so do not show daytime / night highs and lows. To see the daily range of temperatures have a look at the temperature max / min chart below.

Average rainfall & rainy days

The graph below shows the average rainfall and number of rainy days per month.

Napa monthly rainfall chart (mm) Napa monthly rainfall chart (inches)
Average monthly rainfall in Napa (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 157 115 97 47 14 5 1 3 10 41 100 127
inches 6.2 4.5 3.8 1.8 0.5 0.2 0.1 0.1 0.4 1.6 3.9 5
Rainy days 10 9 10 6 3 1 1 1 2 4 9 10

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Napa

Napa average daily sunshine chart
Average daily sunshine Napa
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 6.1 7.9 9.4 11.3 12.2 12.5 12.5 11.5 10.7 9.2 6.6 5.5

Day / night temperatures

The graph below shows the daily range of temperatures for each month.

Napa average minimum / maximum temperatures (Celsius) Napa average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Napa (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 3 4.8 5.4 6.3 8.5 11 12 12.1 11.2 8.9 5.7 3.3
Max °C 12.9 15.9 17.2 19.8 22.9 26.3 28.1 27.9 26.8 23.7 17.1 12.9
Min °F 37.3 40.6 41.7 43.3 47.3 51.7 53.5 53.8 52.2 48 42.3 37.9
Max °F 46.2 50.5 52.3 55.4 60.3 65.5 68 68 66.2 61.3 52.5 46.6

Sea temperature

The graph below shows the average sea temperature.

Napa average sea temperature chart (Celsius) Napa average sea temperature chart (Fahrenheit)
Average sea temperature around Napa in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 12.1 12 11.9 11.7 11.8 12.2 13.1 14 14.4 14 13.4 12.6
°F 53.8 53.6 53.5 53.1 53.2 54 55.5 57.2 57.9 57.3 56.1 54.6

Wind speed

The graph below shows the average wind speed.

Napa average winspeed by month (km/h) Napa average winspeed by month (mph)
Average wind speed in Napa (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 12 14 16 17 19 19 18 17 15 13 12 12
mph 7 9 10 11 12 12 11 11 9 8 7 7

A monthly average windspeed of over 16km/h or 10mph suggests a location is fairly windy.

Relative humidity

The graph below shows the average relative humidity.

Napa relative humidity averages
Average relative humidity in Napa
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
81% 77% 72% 68% 66% 64% 63% 66% 65% 68% 76% 81%

Other monthly averages

UV index Best time to go?

Napa weather stats

Napa weather statistics
Hottest month: July 27.7°C 81.9°F
Driest month: July 1mm 0ins
Sunniest month: May 12.2hrs
Coldest month: January 12.6°C 54.7°F
Wettest month: January 157mm 6.2ins
Warmest sea: September 14.4°C 57.9°F
Map showing location of Napa (38.29714, -122.28553)

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