Rennes Climate & Monthly Temperature Overview – France

Summer in Rennes

Summer in Rennes spans from June to August and is generally warm and sunny, although occasional thunderstorms can occur. Average temperatures range from 15°C (59°F) to 25°C (77°F), with highs sometimes reaching 30°C (86°F). The days are long, with about 15 hours of daylight, providing ample opportunities for outdoor activities. Rainfall is moderate, averaging around 55mm (2.2 inches) per month.

Winter in Rennes

Winter in Rennes lasts from December to February and is typically chilly and overcast. Average temperatures hover around 5°C (41°F), with lows occasionally dipping below 0°C (32°F). Snowfall is infrequent, but when it occurs, it can accumulate up to a few centimeters. The days are short, with only around 8 hours of daylight. Rainfall is common, averaging about 70mm (2.8 inches) per month. Fog and mist are also prevalent during this time, particularly in the mornings.

Seasonal Variations

Rennes experiences distinct seasonal variations in average temperature. The warmest months are July and August, with average highs of around 25°C (77°F) and average lows of 14°C (57°F). Winters are mild, with average temperatures ranging from 8°C (46°F) in December to 10°C (50°F) in February. The coldest month is January, with average highs of 9°C (48°F) and lows of 3°C (37°F).

Year-Round Averages

Overall, Rennes has a temperate climate, with annual average temperatures ranging from 10°C (50°F) to 12°C (54°F). The city experiences an average of 1,600 hours of sunshine per year, with the sunniest months being June and July. Precipitation is distributed evenly throughout the year, with an annual average of around 800 millimeters (31 inches).

High-Level Cloud Cover

Rennes, France, experiences a range of cloud cover throughout the year, influenced by its temperate oceanic climate. During the winter months (December to February), high-level clouds, such as cirrus and cirrostratus, are common. These clouds are thin and wispy, allowing some sunlight to penetrate. They often produce halos or sundogs, spectacular optical phenomena that create colorful rings or arcs around the sun.

Mid-Level Cloud Cover

In spring and autumn (March to May and September to November), mid-level clouds, primarily altostratus and altocumulus, are prevalent. Altostratus clouds form a uniform, gray layer that can obscure the sun, casting a diffuse light. Altocumulus clouds, on the other hand, are characterized by their rounded masses or rolls. They often precede the arrival of a warm front and can bring light rain or drizzle.

Low-Level Cloud Cover

During the summer months (June to August), низкие облака, such as stratus and stratocumulus, become more frequent. Stratus clouds form a dense, uniform layer that blocks most sunlight, resulting in overcast conditions. Stratocumulus clouds, on the other hand, are composed of irregular patches or clumps that may allow some sunlight to filter through. Both types of low-level clouds are associated with stable atmospheric conditions and can produce persistent rain or drizzle.

Annual Precipitation

Rennes, France, experiences a temperate oceanic climate with evenly distributed precipitation throughout the year. The average annual precipitation is approximately 770 millimeters (30.3 inches). The driest month is February, with an average of 45 millimeters (1.8 inches) of rain, while the wettest month is December, with an average of 85 millimeters (3.3 inches) of rain. Rennes receives ample rainfall during both the winter and summer months, and it rarely experiences extreme drought conditions.

Seasonal Distribution of Precipitation

Precipitation in Rennes varies seasonally, with distinct patterns during the year. The winter months (December to February) are generally the wettest, with an average monthly precipitation of over 70 millimeters (2.8 inches). The spring months (March to May) are slightly drier, with an average monthly precipitation of around 60 millimeters (2.4 inches). The summer months (June to August) are typically the driest, with an average monthly precipitation of less than 50 millimeters (2 inches). However, occasional thunderstorms can bring significant rainfall during this period. The autumn months (September to November) are characterized by a gradual increase in precipitation, with an average monthly precipitation of around 60 millimeters (2.4 inches).

Rainfall Patterns in Rennes

Rennes, the capital of Brittany in northwestern France, experiences a temperate oceanic climate characterized by moderate rainfall throughout the year. The average annual precipitation is around 32 inches (810 mm), with more significant amounts occurring during the winter months. From October to February, rainfall is typically heaviest, with an average of 3 to 4 inches (76 to 102 mm) per month. During the spring and summer, rainfall becomes less frequent but can still occur in the form of occasional showers or thunderstorms.

Seasonal Variations in Rainfall

The seasonal distribution of rainfall in Rennes is influenced by the prevailing westerly winds and the city’s location near the Atlantic Ocean. In the winter, these winds carry moisture-laden air from the ocean, leading to more frequent and intense rainfall. In contrast, during the summer, the winds weaken, and the air becomes drier, resulting in less precipitation. As a result, summers in Rennes are typically warm and dry, with an average of only 2 to 3 inches (51 to 76 mm) of rainfall per month.

Snowfall in Rennes, France

Snowfall in Rennes, France is a rare occurrence that typically only occurs a few times per year. The last snowfall in Rennes was in February 2018, when the city was blanketed in 10 centimeters of snow. The heaviest snowfall in recent history occurred in January 1987 when Rennes received 25 centimeters of snow. Temperatures in Rennes during the winter months average between 3 and 9 degrees Celsius, so when temperatures drop below freezing, snowfall is possible.

The effects of snowfall in Rennes can be significant. Snowfall can cause traffic congestion, delays, and cancellations. Schools and businesses may close, and public transportation may be disrupted. Snowfall can also cause power outages and damage to infrastructure. On the other hand, snowfall can also be a beautiful sight, and many people enjoy participating in winter activities such as sledding, snowboarding, and skiing.

Temperature and Humidity

Rennes, located in the northwest of France, experiences moderate temperatures and humidity levels throughout the year. Summers are typically warm and sunny, with average high temperatures ranging from 22 to 26 degrees Celsius (72 to 79 degrees Fahrenheit). Winters are relatively mild, with average low temperatures hovering around 2 to 5 degrees Celsius (36 to 41 degrees Fahrenheit). Humidity levels remain fairly constant throughout the year, with an average of around 75-85%. This combination of moderate temperature and humidity makes Rennes a comfortable place to visit or reside.

Precipitation and Sunshine

Rennes receives a moderate amount of precipitation throughout the year, with an average of around 800 mm (32 inches) annually. Rainfall is spread relatively evenly throughout the year, but tends to be slightly higher during the winter months. The city also experiences a significant amount of sunshine, averaging around 2,000 hours per year. This provides ample opportunities to enjoy outdoor activities and explore the region’s natural beauty. However, it’s important to note that showers or drizzle can occur at any time of the year, so it’s always a good idea to have an umbrella or raincoat at hand.

Moonrise and Moonset Times in Rennes, France

In Rennes, France, the moonrise and moonset times vary throughout the year. During the summer months, the moon rises later and sets later, resulting in longer nights. Conversely, during the winter months, the moon rises earlier and sets earlier, leading to shorter nights.

Moon Phases in Rennes, France

Throughout the month, the moon progresses through different phases. The new moon, when the moon is not visible from Earth, occurs every 29.5 days. The full moon, when the moon is fully illuminated by the sun, appears opposite the sun in the sky. The waxing crescent, waxing gibbous, waning gibbous, and waning crescent phases occur in between the new and full moons. Each phase lasts approximately 7 days. The moon’s phase influences the amount of moonlight available at night, affecting activities such as stargazing and nocturnal wildlife behavior.

Average Humidity Levels

Rennes, a city in northwestern France, experiences moderate humidity levels throughout the year. On average, the relative humidity hovers around 80% in the morning, gradually decreasing to about 65% in the afternoon. This pattern is consistent across the seasons, with slightly higher humidity levels during the winter months (December to February) and slightly lower levels during the summer months (June to August).

Seasonal Variations

Seasonal variations in humidity are primarily influenced by the amount of precipitation and temperature. During the winter, frequent rainfall and lower temperatures contribute to higher humidity levels. In contrast, during the summer, warmer temperatures and less rainfall result in lower humidity levels, making the air feel more comfortable and less muggy. It is worth noting that while humidity levels in Rennes are generally moderate, they can occasionally spike during periods of heavy rainfall or fog.

Wind Patterns and Characteristics

The wind regime in Rennes, France, is primarily influenced by its location in the Atlantic Ocean basin and its proximity to the English Channel. The prevailing winds originate from the west-southwest, bringing moist air from the Atlantic. During the winter months, these winds can be particularly strong, with frequent gusts and occasional storms. In summer, the winds tend to be lighter and come from a more southerly direction, contributing to the city’s warm and sunny climate.

Influence on Local Climate and Air Quality

The prevailing winds have a significant impact on the local climate and air quality in Rennes. The moist air from the Atlantic contributes to the city’s humid and temperate conditions, with mild winters and warm summers. Additionally, the winds help to disperse pollutants in the atmosphere, resulting in relatively good air quality in Rennes compared to other urban areas in France. The wind can also influence the city’s energy production, as it is harnessed by wind turbines to generate clean and renewable energy.

Spring (April-May):

Spring in Rennes is a delightful time to visit, offering a burst of color and warmth after the long winter months. The city awakens from its slumber, as parks and gardens bloom in vibrant hues. The weather is generally pleasant, with moderate temperatures ranging from 10-18°C (50-64°F). This makes it an ideal time for leisurely walks, outdoor dining, and exploring the charming Old Town. In early May, the annual Transmusicales Festival showcases a diverse lineup of national and international artists.

Summer (June-August):

Summer months in Rennes bring warm and sunny weather, with average temperatures hovering around 22°C (72°F). The city transforms into a lively hub of activity, with locals and tourists alike soaking up the sunshine. The streets are filled with outdoor concerts, street performers, and bustling markets. The annual Les Tombées de la Nuit festival, taking place throughout July and August, offers a captivating blend of music, theater, and dance performances in various outdoor venues. However, it’s worth noting that summer can be crowded, and accommodations should be booked well in advance.

Solar Radiation and Potential

Rennes, the capital of Brittany in northwestern France, enjoys ample solar radiation due to its coastal location and temperate climate. According to the National Oceanic and Atmospheric Administration (NOAA), Rennes receives an average of 1,550 sunshine hours annually, with peak irradiance levels occurring during the summer months. This solar resource potential makes the city well-suited for solar energy utilization.

Solar Power Installations and Initiatives

Recognizing the potential of solar energy, Rennes has implemented several initiatives to promote its adoption. The city has installed numerous solar photovoltaic (PV) systems on rooftops, parking lots, and other urban areas. These systems generate clean, renewable electricity that contributes to the city’s energy mix. Additionally, the city offers incentives to residents and businesses for the installation of solar panels. As a result, solar energy has become increasingly popular in Rennes, with a growing number of homes and businesses harnessing the power of the sun.

Topography of Rennes

Rennes, the capital of the Brittany region in northwestern France, is a city of diverse topography. The city center is situated on a hilltop, providing panoramic views of the surrounding countryside. The river Vilaine flows through the city, creating a natural boundary between the historic center and the newer districts to the south. The landscape surrounding Rennes is characterized by rolling hills, forests, and meadows. To the west of the city lie the vast moors of Brocéliande, a legendary forest associated with the Arthurian legends.

Geological Influences

The topography of Rennes has been shaped by geological processes over millions of years. The city is located on the Armorican Massif, an ancient mountain range that has been eroded over time. The underlying rock formations consist of metamorphic and sedimentary rocks, including granite, schist, and sandstone. The river Vilaine has played a significant role in shaping the landscape, carving out a valley that has been widened and deepened by glaciers during the ice ages. The result is a varied topography that includes riverbanks, terraces, and hills. The presence of granite has contributed to the construction of many of Rennes’ historical buildings, as this durable material has been used for centuries to build fortifications and churches.

Rennes-Saint-Jacques Airport (RNS)

Rennes-Saint-Jacques Airport (RNS) is the closest airport to Rennes, France. It is located approximately 7 kilometers (4 miles) southwest of the city center and serves as a gateway to the Brittany region. RNS offers a range of domestic and international flights, connecting Rennes to major cities in France and destinations across Europe. The airport has a single passenger terminal with modern facilities, including duty-free shops, restaurants, and lounges. It is easily accessible by public transportation, with a direct bus service connecting the airport to the city center and train station.

Transportation Options

There are several convenient transportation options available to get from RNS to Rennes city center. The Star bus line C6 operates regularly between the airport and the city center, with a journey time of around 25 minutes. The journey by taxi takes approximately 15-20 minutes, while ride-sharing services like Uber are also available. Additionally, long-distance trains and buses depart from the Rennes train station, which is conveniently located within walking distance of the airport. The journey to Paris by high-speed train takes approximately 1 hour 30 minutes.

Culture and History in Rennes

Rennes, the capital of Brittany, boasts a rich cultural tapestry intertwined with its captivating history. The city’s heart is Place de la Mairie, overlooked by the majestic Hôtel de Ville, a testament to its architectural prowess. Rennes is renowned for its vibrant arts scene, hosting numerous festivals throughout the year, including Transmusicales, an international music event that has showcased emerging artists for decades. The city also exudes a literary flair, being the birthplace of the famous writer François-René de Chateaubriand, and is home to numerous bookstores and cultural institutions.

Modern Metropolis

Rennes seamlessly blends its historic charm with a vibrant modern character. As a major economic hub in Western France, the city is home to a thriving tech industry, attracting a young and dynamic population. It boasts a bustling pedestrianized center lined with charming cafés and shops, inviting visitors to soak in the city’s lively atmosphere. Rennes also prioritizes sustainability, with an extensive network of public transportation and a strong commitment to green spaces. Notable landmarks include the contemporary art museum, FRAC Bretagne, and the futuristic Les Champs Libres, housing the city’s library, museum, and science center.