Rio Grande Temperature by Month

Rio Grande in Puerto Rico enjoys a stable climate, with daytime temperatures staying close to 29°C (84°F) throughout the year. Explore the full monthly breakdown below.

The climate in Rio Grande remains fairly constant, offering comfortable temperatures throughout the year. Maximum daytime temperatures reach a very warm 31°C (88°F) in August, dropping to a comfortable 28°C (82°F) in January. Nighttime lows stay between 26°C (79°F) and 23°C (73°F).

The chart below illustrates the average maximum day and minimum night temperatures in Rio Grande by month:

The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest. August, the warmest month, gets 267 hours of sunshine.

The chart below shows the average temperature throughout the year:

Rio Grande's average annual maximum temperature is 29°C (84°F). To put that in context, here's how it compares to a few well-known destinations:

Seville, Spain averages 23°C (73°F) a year, one of the warmer cities in Western Europe, with long hot summers.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation, summers are often cool and foggy, winters mild.

Melbourne, Australia averages 20°C (68°F) annually, known for unpredictable weather, with four seasons sometimes happening in one day.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Rio Grande, January is the coolest month, with average highs of 28°C (82°F) and humidity around 74%, considered high. In August, the warmest month, temperatures average 31°C (88°F) with 76% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Rio Grande's weather, including monthly rainfall, sunshine hours, and humidity, visit our Rio Grande climate page.