Rio Grande Weather in August
August in Rio Grande brings very high temperatures, with daytime highs of 31°C (88°F) and nights around 26°C (79°F). Quite a bit of rainfall is expected, around 135 mm (5.3 in), so pack an umbrella.
Rainfall in Rio Grande in August
Rain is expected on roughly 20 days, totalling around 135 mm (5.3 in) for the month. Wet weather is a regular and significant part of this month. Frequent days of rain combined with high totals means proper waterproofs are worth packing.
Temperature in Rio Grande in August
August in Rio Grande brings typical temperatures with highs around 31°C (88°F) and lows of 26°C (79°F). Mornings and evenings are often more comfortable than the peak afternoon hours. Nights are warm at 26°C (79°F). It's worth making sure your accommodation has decent ventilation or air conditioning.
Sunshine in Rio Grande in August
The days are predominantly sunny, with an estimated total of around 267 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.
Wind Speed in Rio Grande in August
August has wind speeds averaging 3 m/s (6 knots). You can expect comfortable light winds that steadily move flags and feel mild throughout the day. Since this is an average, daily conditions vary from gentle winds to more active breezes.
Average water temperature in August
The water is 29°C (84°F) — very warm by most standards. Comfortable to swim in, but not particularly refreshing if you're looking to cool off.August in Rio Grande has its charm, but if you're looking for destinations with pleasant temperatures and sunny skies, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our Rio Grande's climate page.
Rio Grande Temperature in August
Min Temperature
26°C (79°F)
Max Temperature
31°C (88°F)
Water Temperature
29°C (84°F) *
Chance of Rain
67%
Precipitation
135 mm (5.3 in)
Rainy days
20 days
Humidity
76% *
Windspeed
3 m/s (6 knots) *
Sunshine
267 hours *
Percentage Sunshine
68% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Rio Grande typically stay consistent throughout August, with daily highs averaging around 31°C (88°F). Nights are warm, with lows around 26°C (79°F).
Average temperatures in August
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in August
Historical weather for Rio Grande in August
Browse day-by-day weather records for Rio Grande spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Rio Grande historical weather extremes in August
Based on weather observations in Rio Grande between 1976 and 2025, these are the recorded extremes during August.
- The hottest August day on record in Rio Grande reached 35°C (95°F) (August 20, 1980).
- The coldest August day was on August 24, 1988, with a maximum of 26°C (79°F).
- Rio Grande registered its coldest August night on August 24, 1988, with temperatures dropping to 23°C (73°F).
Best Places in Puerto Rico in August
Find out more about the weather in Puerto Rico and which places have the best travel conditions in this month. See all of Puerto Rico in August →
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What to Wear in Rio Grande in August
Warm weather calls for comfortable, breathable clothing in August. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). High rain levels are expected, so pack waterproof gear and an umbrella or poncho. The water temperature sits at about 29°C (84°F), making it perfect for swimming and water activities. Don't forget to pack your favorite swimwear and perhaps some snorkel gear. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in Rio Grande in August
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our Rio Grande's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Rio Grande climate overview or explore weather in Puerto Rico.
