Climate in Rennes (Brittany)

The climate of Rennes is suboceanic, with quite mild, rainy winters and warm summers.
The city is located in north-western France, in the eastern part of Brittany, of which it is the capital.

Winter is a bit milder than in the rest of northern France, however, it is not as influenced by the ocean than the coasts of Brittany. Anyway, the sky is often cloudy, the humidity is high and there are periods when the wind blows moderate or strong. Rainfall is frequent.
Cold waves are shorter and less intense than in Paris and in the interior of France, but are a little more intense than on the coasts of Brittany (see Saint-Malo, Brest). However, there may occasionally be cold periods, in which the temperature drops below freezing, and it can even snow. The temperature dropped to -14.5 °C (6 °F) in January 1985.

In summer, temperatures are mild or pleasantly warm. It can also rain, but less often than in winter.
Hot days are rare, but the city is a little more exposed to heat waves than the coasts of Brittany, even though up here they usually last a few days, sometimes just a day or two. The highest record is 40.5 °C (104.9 °F), set in July 2022. The previous record was 40 °C (104 °F) and was set in July 2019. In August 2003, when there were seven days with more than 35 °C (95 °F), and in the summer of 2022 eight days, from June to August.

Best Time

The best time to visit Rennes runs from mid-May to mid-September, since it is the warmest and sunniest period of the year. Sometimes, it can be hot in July and August, while in other circumstances, nights can be cool or even a little cold even in these months, so it can be useful to bring a sweatshirt or sweater and a light jacket for the evening.

Rennes - Climate data

In Rennes, the average temperature of the coldest month (January) is of 6.2 °C (43.2 °F), that of the warmest months (July, August) is of 19.3 °C (66.7 °F). Here are the average temperatures.
Precipitation amounts to 695 millimeters (27.4 inches) per year: so, it is at an intermediate level. It ranges from 40 mm (1.6 in) in the driest month (August) to 75 mm (3 in) in the wettest ones (October, December) Here is the average precipitation.
There are on average around 1720 sunshine hours per year. Here are the average hours of sunshine per day.

Rennes - Weather by month

Based on the period 1991-2020

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January, the coldest month of the year, is generally a quite cold month. The average temperature is of 6.2 °C (43 °F), with a minimum of 3.3 °C (37.9 °F) and a maximum of 9.2 °C (48.6 °F).
On the coldest nights of the month, the temperature usually drops to around -4.5 °C (23.5 °F). However, it dropped to -11.3 °C (11.7 °F) in January 1997.
On the warmest days of the month, the temperature usually reaches around 14.5 °C (58 °F). However, it reached 16.8 °C (62.2 °F) in January 2003.
Precipitation amounts to 70 mm (2.8 in), distributed over 11 days.
The day lasts on average 8 hours and 50 minutes.
There are on average 2 hours of sunshine per day. So, the sun shines 25% of the time.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 14 kph (9 mph).

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February is generally a quite mild month. The average temperature is of 6.6 °C (44 °F), with a minimum of 3 °C (37.4 °F) and a maximum of 10.2 °C (50.4 °F).
On the coldest nights of the month, the temperature usually drops to around -3.5 °C (25.5 °F). However, it dropped to -10.8 °C (12.6 °F) in February 1991.
On the warmest days of the month, the temperature usually reaches around 15.5 °C (60 °F). However, it reached 20.9 °C (69.6 °F) in February 2019.
Precipitation amounts to 50 mm (2 in), distributed over 9 days.
The day lasts on average 10 hours and 10 minutes.
There are on average 3 hours of sunshine per day. So, the sun shines 31% of the time.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 14 kph (9 mph).

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March is generally a mild month. The average temperature is of 8.8 °C (48 °F), with a minimum of 4.5 °C (40.1 °F) and a maximum of 13.2 °C (55.8 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -2 °C (29 °F). However, it dropped to -7.3 °C (18.9 °F) in March 2005.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 19.5 °C (67 °F). However, it reached 23.4 °C (74.1 °F) in March 2017.
Precipitation amounts to 50 mm (2 in), distributed over 10 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 35% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is 14 kph (9 mph).

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April is generally a mild month. The average temperature is of 11 °C (52 °F), with a minimum of 6 °C (42.8 °F) and a maximum of 16 °C (60.8 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 0 °C (32 °F). However, it dropped to -2.8 °C (27 °F) in April 1996.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 23 °C (74 °F). However, it reached 27.7 °C (81.9 °F) in April 2018.
Precipitation amounts to 50 mm (2 in), distributed over 10 days.
The day lasts on average 13 hours and 50 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 39% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).

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May is generally a mild month. The average temperature is of 14.4 °C (58 °F), with a minimum of 9.3 °C (48.7 °F) and a maximum of 19.4 °C (66.9 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 3.5 °C (38.5 °F). However, it dropped to -1.1 °C (30 °F) in May 2019.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 27 °C (81 °F). However, it reached 30.3 °C (86.5 °F) in May 1992.
Precipitation amounts to 65 mm (2.6 in), distributed over 10 days.
The day lasts on average 15 hours and 20 minutes. So the days are long.
There are on average 6 hours of sunshine per day. So, the sun shines 40% of the time.
The average humidity is 73%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).

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June is generally a very mild month. The average temperature is of 17.4 °C (63 °F), with a minimum of 12.1 °C (53.8 °F) and a maximum of 22.6 °C (72.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 6.5 °C (44 °F). However, it dropped to 3.5 °C (38.3 °F) in June 2006.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 31 °C (88 °F). However, it reached 35.7 °C (96.3 °F) in June 2019.
Precipitation amounts to 45 mm (1.8 in), distributed over 7 days.
The day lasts on average 16 hours and 5 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 7 hours of sunshine per day. So, the sun shines 45% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).

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July, the warmest month of the year, is generally a warm month. The average temperature is of 19.3 °C (67 °F), with a minimum of 13.8 °C (56.8 °F) and a maximum of 24.8 °C (76.6 °F).
On the coldest nights of the month, the temperature usually drops to around 9 °C (48.5 °F). However, it dropped to 6.8 °C (44.2 °F) in July 2004.
On the warmest days of the month, the temperature usually reaches around 32.5 °C (90.5 °F). However, it reached 40.1 °C (104.2 °F) in July 2019.
Precipitation amounts to 50 mm (2 in), distributed over 7 days.
The day lasts on average 15 hours and 35 minutes. So the days are long.
There are on average 7 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).

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August, the warmest month of the year, is generally a warm month. The average temperature is of 19.3 °C (67 °F), with a minimum of 13.8 °C (56.8 °F) and a maximum of 24.8 °C (76.6 °F).
On the coldest nights of the month, the temperature usually drops to around 8.5 °C (47.5 °F). However, it dropped to 6.7 °C (44.1 °F) in August 1998.
On the warmest days of the month, the temperature usually reaches around 32.5 °C (90.5 °F). However, it reached 39.5 °C (103.1 °F) in August 2003.
Precipitation amounts to 40 mm (1.6 in), distributed over 6 days.
The day lasts on average 14 hours and 10 minutes. So the days are long.
There are on average 6.5 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).

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September is generally a very mild month. The average temperature is of 16.6 °C (62 °F), with a minimum of 11.4 °C (52.5 °F) and a maximum of 21.9 °C (71.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 6 °C (42.5 °F). However, it dropped to 2.5 °C (36.5 °F) in September 2018.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 28.5 °C (83 °F). However, it reached 34.2 °C (93.6 °F) in September 2020.
Precipitation amounts to 60 mm (2.4 in), distributed over 8 days.
The day lasts on average 12 hours and 30 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).

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October is generally a mild month. The average temperature is of 13.2 °C (56 °F), with a minimum of 9.3 °C (48.7 °F) and a maximum of 17.2 °C (63 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 2 °C (36 °F). However, it dropped to -4 °C (24.8 °F) in October 1997.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 22.5 °C (72.5 °F). However, it reached 30 °C (86 °F) in October 2011.
Precipitation amounts to 75 mm (3 in), distributed over 11 days.
The day lasts on average 10 hours and 40 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 36% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).

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November is generally a mild month. The average temperature is of 9.2 °C (49 °F), with a minimum of 5.9 °C (42.6 °F) and a maximum of 12.5 °C (54.5 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -1.5 °C (29.5 °F). However, it dropped to -6 °C (21.2 °F) in November 2010.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 17.5 °C (64 °F). However, it reached 21.4 °C (70.5 °F) in November 2015.
Precipitation amounts to 70 mm (2.8 in), distributed over 12 days.
The day lasts on average 9 hours and 10 minutes.
There are on average 2.5 hours of sunshine per day. So, the sun shines 30% of the time.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).

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December is generally a quite mild month. The average temperature is of 6.6 °C (44 °F), with a minimum of 3.6 °C (38.5 °F) and a maximum of 9.6 °C (49.3 °F).
On the coldest nights of the month, the temperature usually drops to around -4 °C (24.5 °F). However, it dropped to -8.4 °C (16.9 °F) in December 2009.
On the warmest days of the month, the temperature usually reaches around 14.5 °C (58.5 °F). However, it reached 17.8 °C (64 °F) in December 2015.
Precipitation amounts to 75 mm (3 in), distributed over 12 days.
The day lasts on average 8 hours and 25 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 2 hours of sunshine per day. So, the sun shines 26% of the time.
The average humidity is 88%. Hence, the air is normally humid.
The average wind speed is 14 kph (8 mph).