Rio Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Rio, Peloponnese, Greece. This average is based on long-term data collected between 1990 and 2020. Let's now guide you through the details for a complete overview.

Generally, Rio receives mid-range precipitation levels, with 955 mm (38 in) annually. The distribution varies significantly throughout the year, with a distinct dry season during certain months, as shown in our charts below.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

The climate in Rio shows significant variation throughout the year. Expect 133 mm (5.2 in) of precipitation during the wettest month December, distributed over 13 rainy days.

In contrast, August offers drier and sunnier days, with around 18 mm (0.7 in) of rainfall over 3 rainy days.

December, the wettest month, has a maximum daytime temperature of 13°C (55°F). The city receives 108 hours of sunshine in this period. During the driest month August you can expect a temperature of 31°C (88°F). For more detailed insights into the city's temperatures, visit our Rio Temperature page.

Rio's average annual precipitation is 955 mm (38 in). Let's compare this to some popular worldwide tourist destinations:

New York City, USA, receives 1276 mm (50 in) of rainfall annually, with precipitation evenly distributed throughout the year.

In Seoul, South Korea, the average annual precipitation is 1237 mm (49 in), with most rain falling during the summer monsoon season.

Melbourne, Australia, has 690 mm (27 in) of rainfall annually, spread fairly evenly throughout the year.

Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm (66 in) of annual rainfall, with the heaviest precipitation occurring during September and October.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

Precipitation has a very strong role in determining the local climate and ecosystem:

• Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
• Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.

• The U.S. has a significant number of thunderstorms every year, with over 14.6 million taking place across the world annually.
• Approximately 70% of lightning bolts strike land rather than oceans.
• A storm named John was the longest-lasting Pacific tropical storm, continuing for 31 days. As it crossed the dateline twice, it changed status from a hurricane to a typhoon and back to a hurricane.

For more detailed information about Rio's weather, including sunshine hours, humidity levels, and temperature data, visit our Rio Climate page.