Rio Grande Weather in December

December in Rio Grande averages 28°C (82°F) during the day and 24°C (75°F) at night. Quite a bit of rainfall is typical this month, with around 78 mm (3.1 in) on average. An umbrella is a good idea.

Rainfall in Rio Grande in December

Rain is expected on roughly 21 days, totalling around 78 mm (3.1 in) for the month. This is a month with many wet days but modest rainfall totals, so showers are generally light and easy to manage.

Temperature in Rio Grande in December

The temperature in Rio Grande in December is perfect. Daytime highs reach 28°C (82°F), with nights dropping to 24°C (75°F). This kind of day-to-night contrast is typical for this time of year. Nights stay warm at around 24°C (75°F), so light bedding and good ventilation are worth thinking about.

Sunshine in Rio Grande in December

The days are predominantly sunny, with an estimated total of around 216 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 December

Average wind speeds reach 3 m/s (6 knots) in December, creating light breezes that feel pleasant throughout the day. Some days are calmer, while others bring slightly more active breezes.

Average water temperature in December

With water at 27°C (81°F), you can expect warm, pleasant conditions for any water activity. There's no adjustment period — it feels comfortable straight away.

If you're inclined towards comfortable temperatures and drier conditions, December is a good time to visit Rio Grande.

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Check the conditions for any month of the year.

• January
• February
• March
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• May
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• August

• September
• October
• November
• December

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 December

Min Temperature 24°C (75°F)  

Max Temperature 28°C (82°F)  

Water Temperature 27°C (81°F) *  

Chance of Rain 70%  

Precipitation 78 mm (3.1 in)  

Rainy days 21 days  

Humidity 75% *  

Windspeed 3 m/s (6 knots) *  

Sunshine 216 hours *  

Percentage Sunshine 64% *  

* Data from: San Juan, Puerto Rico (18 KM, 11 Miles).

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Rio Grande typically stay consistent throughout December, with daily highs averaging around 28°C (82°F). Nights are warm, with lows around 23°C (73°F).

Average temperatures in December

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‹ January February March April May June July August September October November December ›

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 December

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‹ January February March April May June July August September October November December ›

Historical weather for Rio Grande in December

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.

Historical weather Temperatures Precipitation

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‹ January February March April May June July August September October November December ›

Rio Grande historical weather extremes in December

The extremes listed below come from historical weather data collected in Rio Grande from 1976 through 2025.

• The hottest December day on record in Rio Grande reached 33°C (91°F) (December 6, 1989).
• The lowest daytime temperature in December was 25°C (77°F), recorded on December 29, 2010.
• Nighttime temperatures dropped to 19°C (66°F) on December 24, 1991, marking the coldest December night on record.

What to Wear in Rio Grande in December

Warm temperatures in December make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Rain gear is recommended, you can expect wet weather on multiple days. Expect water temperatures of around 27°C (81°F), which is ideal for taking a refreshing dip. Bring swimwear and consider packing a towel for drying off. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Rio Grande in December

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

9/10

Cycling

7/10

Walking

7/10

Camping

8/10

Outdoor sports

7/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Puerto Rico, check out our Rio Grande's climate page.

More climate data for Rio Grande

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Rio Grande climate overview or explore weather in Puerto Rico.