Weather in San Juan in August 2025
Average weather
Average temperature in San Juan in August
Going from a maximum of +95°F during the day to a minimum of +77°F during the night, the temperature in August averages around +90°F.
The average maximum temperature goes up 0% by the end of the month, compared with the beginning of the month, from +90°F to +90°F.
Is San Juan warm or cold in August?
San Juan is typically hot in August.
Maximum temperatures go up compared to the previous month from +88°F to +88°F. The minimum temperature also goes up from +79°F to +79°F.
Make sure that you pack your summer linen and swimming costumes; it’s probably going to be hot.
August is one of the warmest months in San Juan, here is the comparison with other months:
Water temperature in San Juan in August
Water in San Juan in August is Very warm. It varies from +83°F to +86°F, with an average of +84°F. This is almost similar to the air temperature, which averages +88°F.
The water temperature in August is one of the warmest of the entire year:
Can you swim in San Juan in August?
Climate in San Juan in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +88°F | +88°F | +88°F | ||||
| Min. temperature | ||||||
| +73°F | +73°F | +73°F | ||||
| Max. temperature | ||||||
| +95°F | +95°F | +95°F | ||||
| Rainfall | ||||||
| 84 mm | 106 mm | 148 mm | ||||
| Wind | ||||||
| 3 m/s | 3 m/s | 2 m/s | ||||
| Avg. water temperature | ||||||
| +83°F | +84°F | +85°F | ||||
| Humidity | ||||||
| 78% | 78% | 78% | ||||
| Air pressure | ||||||
| 1016 HPa | 1015 HPa | 1013 HPa | ||||
| Sunny days | ||||||
| 1 | 1 | 1 | ||||
| Cloudy days | ||||||
| 5 | 3 | 2 | ||||
| Rainy days | ||||||
| 21 | 22 | 20 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as ok as in July. The temperature levels stay the same in the area of +88°F for average maximum temperature during the day. Prepare for more rain. Average rainfall goes from 84 mm to 106 mm. Humidity levels don’t change as the month goes on, averaging around 78%. The average wind speed doesn’t change much during August, staying around 3 m/s. The amount of sunny days stay about the same, averaging 1 sunny days during the month.
September brings much the same weather, it remains ok.
Wind
The average wind speed is 4 m/s getting up to 7 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in San Juan is gradually increasing during August, going from 4 m/s to 4 m/s over the course of the month.
Rain
How was the weather last August in San Juan?
Climate Change Over the Years
The climate in San Juan in August has not changed that much over the last 43 years.
The average temperature was the lowest in 2008 (+84°F) and the highest in 2013 (+87°F). The driest year was 1994 with only 675 mm of rainfall, and the wettest year was 2023 with 2338 mm.
FAQ
Is August a good time to visit San Juan?
Can you sunbathe in San Juan in August?
Can you swim in San Juan in August?
Is San Juan rainy in August?
Is it sunny in San Juan in August?
Monthly weather in San Juan
Source of the data
For this page, we’ve looked at the typical weather in San Juan, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.