Rennes weather in May

In May, Rennes sees average daytime highs of 18°C and overnight lows near 9°C, with 63 mm of rain across 10.8 wet days and about 14.9 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 17°C in the first days to 20°C by the end. The sky is clear or mostly clear about 17% of the time in May, and the air most often feels dry.

Daylight stretches from about 14 h 12 min at the start of May to 15 h 30 min by month's end. Set against the rest of the year, May is Rennes's 6th-clearest and 8th-windiest month. For the whole year in context, see Rennes's year-round climate.

Daytime high
18°
5th warmest
Overnight low
8th coldest
Rainfall
63 mm
10.8 wet days
Daylight
15 hours
5:34 AM – 8:32 PM
Cloud cover
68%
6th clearest
Wind
13 km/h
8th windiest
Solar energy
5.37 kWh/m²
Travel score
5.6
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 May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 17°C in the first days to 20°C by the end.

A typical May day in Rennes reaches about 18°C in the afternoon and slips back to 9°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 23°C. Set against its neighbours, May runs about 3°C warmer than April and about 3°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1168
2178
3178
4178
5178
6178
7178
8178
9179
10179
11179
12189
13189
14189
15189
16189
17189
18189
19199
201910
211910
221910
231910
241910
251910
261910
272010
282010
292011
302011
312011

How May really feels in Rennes

Once humidity and wind are folded in, May 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

May 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 May compares with the rest of the year at a glance. May is the 5th-warmest and 5th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 17% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 69%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12674
22674
32674
42674
52674
62674
72674
82773
92773
102872
112971
122971
133070
143070
153268
163268
173367
183367
193466
203466
213565
223664
233664
243664
253664
263664
273664
283763
293763
303664
313565

Chance of precipitation in May

Any precipitation

Rennes gets around 63 mm of rain over 10.8 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 35% and peaks near 40% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
140
240
340
439
538
638
737
836
936
1035
1135
1235
1335
1435
1535
1635
1735
1835
1934
2034
2134
2234
2334
2434
2534
2633
2733
2833
2933
3033
3133

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 89% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19730
29640
39640
49550
59550
69460
79460
89370
99370
109370
119370
129280
139280
149280
159280
169280
179280
189190
1990100
2090100
2188111
2287121
2386131
2486131
2585141
2684151
2782162
2881172
2980182
3079192
3177203

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3112light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 14 h 12 min at the start of May to 15 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 78 minutes over May. Sunrise moves from 5:57 AM to 5:19 AM, and sunset from 8:11 PM to 8:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.25:578:11
214.35:558:12
314.35:538:14
414.45:528:15
514.45:508:17
614.55:498:18
714.55:478:19
814.65:458:21
914.65:448:22
1014.75:428:24
1114.75:418:25
1214.85:408:26
1314.85:388:28
1414.95:378:29
1514.95:358:30
1615.05:348:32
1715.05:338:33
1815.05:328:34
1915.15:308:36
2015.15:298:37
2115.25:288:38
2215.25:278:39
2315.25:268:41
2415.35:258:42
2515.35:248:43
2615.45:238:44
2715.45:228:45
2815.45:218:46
2915.55:208:47
3015.55:198:48
3115.55:198:49

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.37 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 — May's 5.37 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.1Bright
85.1Bright
95.1Bright
105.2Bright
115.2Bright
125.2Bright
135.3Bright
145.3Bright
155.3Bright
165.4Bright
175.4Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.6Bright
235.6Bright
245.6Bright
255.6Bright
265.7Bright
275.7Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in May

Is May a good time to visit Rennes?

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

5.6
Sightseeing
5th-best month of the year
2.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Rennes for sightseeing.

What to pack for Rennes in May

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

In May, Rennes sees daytime highs around 18°C and nights near 9°C. Worth packing: rain gear and sun protection. About 11 days see rain.

rain gearsun protection

Sea temperature near Rennes in May

The nearest coast averages about 13°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 6 — 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
May 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).