San Juan monthly weather averages

Average daytime temperature

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

San Juan average temperature chart (Celsius) San Juan average temperature chart (Fahrenheit)
Average monthly temperatures in San Juan (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 26.7 26.9 27.5 28.3 29.3 30 29.9 30.2 30.2 29.9 28.5 27.3
°F 80.1 80.4 81.5 83 84.7 86 85.8 86.3 86.4 85.8 83.4 81.2

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.

San Juan monthly rainfall chart (mm) San Juan monthly rainfall chart (inches)
Average monthly rainfall in San Juan (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 116 82 79 121 182 152 180 195 188 171 178 151
inches 4.5 3.2 3.1 4.8 7.1 6 7.1 7.7 7.4 6.7 7 5.9
Rainy days 20 15 15 14 16 17 19 20 18 18 19 21

Average daily sunshine

The bar chart below shows the average daily sunshine hours in San Juan

San Juan average daily sunshine chart
Average daily sunshine San Juan
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 8.3 8.8 9.6 9.4 8.7 9.1 9.5 9.2 8.3 7.8 7.3 7.6

Day / night temperatures

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

San Juan average minimum / maximum temperatures (Celsius) San Juan average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in San Juan (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 20.1 19.8 20.6 21.3 22.4 23.3 23.6 23.7 23.4 23 22.1 21.1
Max °C 26.9 27.1 27.7 28.5 29.5 30.2 30.1 30.4 30.4 30.1 28.7 27.5
Min °F 68.2 67.6 69 70.3 72.2 73.9 74.4 74.6 74.1 73.3 71.8 70
Max °F 74.3 74.1 75.4 76.8 78.6 80.1 80.2 80.6 80.4 79.7 77.7 75.7

Sea temperature

The graph below shows the average sea temperature.

San Juan average sea temperature chart (Celsius) San Juan average sea temperature chart (Fahrenheit)
Average sea temperature around San Juan in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 26.6 26.2 26.2 26.7 27.5 28.1 28.4 28.7 29 28.9 28.3 27.3
°F 79.9 79.2 79.2 80.1 81.4 82.6 83 83.7 84.2 84 82.9 81.2

Wind speed

The graph below shows the average wind speed.

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

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.

San Juan relative humidity averages
Average relative humidity in San Juan
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
75% 73% 72% 72% 76% 76% 76% 77% 77% 77% 77% 75%

Other monthly averages

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San Juan weather stats

San Juan weather statistics
Hottest month: August 30.2°C 86.4°F
Driest month: March 79mm 3.1ins
Sunniest month: March 9.6hrs
Coldest month: February 26.9°C 80.4°F
Wettest month: August 195mm 7.7ins
Warmest sea: September 29°C 84.2°F
Map showing location of San Juan (18.46633, -66.10572)

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