Rennes weather in August

In August, Rennes sees average daytime highs of 23°C and overnight lows near 14°C, with 47 mm of rain across 8.2 wet days and about 14.1 hours of daylight. It is the 2nd-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 23°C through the month. The sky is clear or mostly clear about 24% of the time in August, and the air most often feels dry.

Daylight stretches from about 14 h 54 min at the start of August to 13 h 18 min by month's end. Set against the rest of the year, August is Rennes's 1st-clearest and 12th-windiest month. For the whole year in context, see Rennes's year-round climate.

Daytime high
23°
2nd warmest
Overnight low
14°
11th coldest
Rainfall
47 mm
8.2 wet days
Daylight
14 h 06 min
6:07 AM – 8:15 PM
Cloud cover
61%
1st clearest
Wind
12 km/h
12th windiest
Solar energy
4.85 kWh/m²
Travel score
7.1
out of 10

Rennes is capital city of the region of Brittany, France.

Air quality
Good
PM2.5 9.4 µg/m³ · 2019
Density
4,521/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 23°C through the month.

A typical August day in Rennes reaches about 23°C in the afternoon and slips back to 14°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 28°C. Set against its neighbours, August runs on par with July and about 3°C warmer than September.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12414
22414
32414
42414
52414
62414
72414
82414
92414
102414
112414
122414
132414
142414
152414
162414
172314
182314
192314
202314
212313
222313
232313
242313
252313
262313
272313
282313
292313
302313
312213

How August really feels in Rennes

Once humidity and wind are folded in, August averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Rennes weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 6411.20.58.61.5
Feb / 529.80.49.91.9
Mar12° / 5210.50.211.63.2
Apr15° / 5811.1013.44.3
May18° / 6310.8014.95.6
Jun21° / 12°539.1015.86.5
Jul23° / 14°467.8015.47.2
Aug23° / 14°478.2014.17.1
Sep21° / 11°498.2012.46.6
Oct16° / 6911.4010.64.9
Nov12° / 6511.3092.9
Dec / 7112.10.38.21.7

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in August, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13961
23961
34060
44258
54258
64258
74258
84258
94357
104456
114555
124555
134555
144654
154555
164555
174456
184456
194357
204258
214258
224258
234258
244159
254159
264159
274258
284159
294258
304357
314357

Chance of precipitation in August

Any precipitation

Rennes gets around 47 mm of rain over 8.2 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 26% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
124
224
324
425
525
626
726
827
927
1028
1128
1229
1329
1429
1529
1629
1729
1829
1928
2028
2127
2227
2326
2425
2524
2624
2723
2822
2922
3021
3121

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the dry band about 40% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
13245212
23244212
33244213
43343213
53343213
63442213
73442213
83442213
93541213
103541213
113641213
123641203
133741203
143740202
153840202
163840192
173940192
183940192
194040192
204039191
214139181
224239181
234438171
244537171
254636161
264836151
274935151
285035141
295234131
305234131
315334121

Wind in August

Winds average 12 km/h in August, the calmest month.

Across August, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912calm
3012calm
3112calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 54 min at the start of August to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 96 minutes over August. Sunrise moves from 5:47 AM to 6:28 AM, and sunset from 8:39 PM to 7:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.95:478:39
214.85:488:37
314.85:498:36
414.75:518:35
514.75:528:33
614.65:538:32
714.65:558:30
814.55:568:28
914.55:578:27
1014.45:598:25
1114.46:008:23
1214.36:018:22
1314.36:038:20
1414.26:048:18
1514.26:068:16
1614.16:078:15
1714.16:088:13
1814.06:108:11
1914.06:118:09
2013.96:138:07
2113.96:148:05
2213.86:158:03
2313.76:178:02
2413.76:188:00
2513.66:207:58
2613.66:217:56
2713.56:227:54
2813.56:247:52
2913.46:257:50
3013.36:277:47
3113.36:287:45

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.85 kWh/m².

For context, solar energy here swings from a low near 0.91 kWh/m² to a high of 5.77 kWh/m² in June across the year — August's 4.85 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.0Bright
125.0Bright
135.0Bright
144.9Bright
154.9Bright
164.9Bright
174.8Bright
184.8Bright
194.8Bright
204.7Bright
214.7Bright
224.7Bright
234.6Bright
244.6Bright
254.6Bright
264.5Bright
274.5Bright
284.5Bright
294.4Bright
304.4Bright
314.4Bright
Planning a trip in August

Is August a good time to visit Rennes?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.1
Sightseeing
2nd-best month of the year
5.7
Beach & pool
2nd-best month of the year

August is one of the better times to visit Rennes for general sightseeing.

What to pack for Rennes in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Rennes sees daytime highs around 23°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 8 days see rain.

light clothesrain gearsun protection

Sea temperature near Rennes in August

The nearest coast averages about 19°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 57 km away) is warmest in August at about 19°C and coldest in February near 8°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan9Bracing
Feb8Bracing
Mar8Bracing
Apr10Bracing
May13Bracing
Jun16Cool
Jul18Cool
Aug19Cool
Sep18Cool
Oct16Cool
Nov13Bracing
Dec10Bracing

UV index in Rennes in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Rennes peaks around June 18 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 18UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5High
May6High
Jun7High
Jul6High
Aug7High
Sep5Moderate
Oct3Moderate
Nov1Low
Dec1Low
Location & terrain

Where is Rennes?

Rennes sits at 48.1°N, 1.7°W, 39 m above sea level, in France. The nearest listed city is Cesson-Sévigné, 5.0 km away.

Topography around Rennes

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Rennes.

Within 3 km, the terrain around Rennes has only modest variations in elevation — a maximum elevation change of 51 m around an average of 40 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 118 m; within 80 km, significant variations in elevation — a maximum elevation change of 353 m.

The land around Rennes is covered by artificial surfaces (63%) and trees (29%) within 3 km, cropland (33%), grassland (28%) and trees (27%) within 16 km, and cropland (44%), grassland (27%) and trees (21%) within 80 km.

3 km
51 m
16 km
118 m
80 km
353 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Cesson-Sévigné 5.0 km · Vitré 35 km · Fougères 44 km · Saint-Malo 65 km · Laval 67 km · Mayenne 81 km · La Chapelle-sur-Erdre 91 km · Carquefou 92 km

France travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 77% of US
price level, 2025
GDP per capita
$48,986
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.3
per 100k, 2023
Road deaths
5.1
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 539
Religion
Roman Catholic 47%none 33%Muslim 4%Protestant 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Rennes (48.1111°, -1.6743°, elevation 39 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).