Rennes Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Rennes, Brittany, France. 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, Rennes has a moderate amount of precipitation, averaging 782 mm (31 in) of rain/snowfall annually.

Monthly Precipitation Levels

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

The wettest period in Rennes occurs in December, which receives around 78 mm (3.1 in) of precipitation. During the driest month, July, Rennes experiences moderate rainfall, totaling approximately 53 mm (2.1 in). The consistent precipitation levels throughout the year contribute to a relatively stable climate.

December, the wettest month, has a maximum daytime temperature of 10°C (50°F). The city receives 68 hours of sunshine in this period. During the driest month July you can expect a temperature of 25°C (77°F). For more detailed insights into the city's temperatures, visit our Rennes Temperature page.

Rennes's average annual precipitation is 782 mm (31 in). Let's compare this to some popular worldwide tourist destinations:

Boston, USA, experiences 1238 mm (49 in) of annual precipitation, including significant snowfall during the winter.

Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.

Adelaide, Australia, enjoys 511 mm (20 in) of annual precipitation, with dry summers and wet winters.

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.

Tropical Rainforests: In tropical regions, rainfall is generally abundant year-round. Areas near the equator, like the Amazon rainforest, can receive up to 3000 mm (118 in) of rain annually.

Desert Regions: Deserts such as the Sahara and Arabian deserts typically see less than 250 mm (9.8 in) of rainfall annually. Rainfall tends to be infrequent, but when it does occur, it is often intense.

Temperate Zones: In temperate regions, precipitation tends to be more evenly distributed, though areas closer to the ocean may see more rain in the winter months, and areas further inland experience drier summers.

Polar Regions: Precipitation in polar regions, like Antarctica, is extremely low, often falling as snow. Average annual precipitation in Antarctica is less than 200 mm (7.9 in), with some areas receiving as little as 50 mm (2 in) annually.

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA, over 31.5 meters (103 feet) fell during the winter of 1972.

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