Saint-Brieuc weather in September

In September, Saint-Brieuc sees average daytime highs of 19°C and overnight lows near 12°C, with 48 mm of rain across 9 wet days and about 12.4 hours of daylight. It is the 3rd-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 18°C by the end. The sky is clear or mostly clear about 21% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Saint-Brieuc's 2nd-clearest and 9th-windiest month. For the whole year in context, see Saint-Brieuc's year-round climate.

Daytime high
19°
3rd warmest
Overnight low
12°
10th coldest
Rainfall
48 mm
9 wet days
Daylight
12 h 18 min
6:55 AM – 7:16 PM
Cloud cover
63%
2nd clearest
Wind
14 km/h
9th windiest
Solar energy
3.64 kWh/m²
Travel score
6.1
out of 10
Air quality
Good
PM10 15.4 µg/m³ · 2019

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 20°C in the first days to 18°C by the end.

A typical September day in Saint-Brieuc reaches about 19°C in the afternoon and slips back to 12°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 23°C. Set against its neighbours, September runs about 2°C cooler than August and about 4°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
12013
22013
32013
42013
52013
62013
72012
82012
92012
102012
112012
122012
131912
141912
151912
161912
171912
181912
191912
201912
211911
221911
231811
241811
251811
261811
271811
281811
291811
301811

How September really feels in Saint-Brieuc

Once humidity and wind are folded in, September 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

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

Saint-Brieuc weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 6011.40.38.61.5
Feb / 5311.10.59.91.7
Mar11° / 5110.70.311.62.7
Apr13° / 5711.8013.43.6
May16° / 62110154.9
Jun19° / 12°569.5015.86.0
Jul21° / 13°469.1015.56.6
Aug21° / 14°499.5014.16.5
Sep19° / 12°489012.46.1
Oct16° / 10°6812.1010.64.5
Nov12° / 6412.6092.8
Dec / 7113.10.58.21.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 60%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14357
24456
34555
44654
54654
64654
74654
84456
94456
104456
114357
124258
134159
144060
154060
163961
173961
183961
193862
203763
213763
223664
233664
243565
253466
263466
273466
283367
293268
303169

Chance of precipitation in September

Any precipitation

Saint-Brieuc gets around 48 mm of rain over 9 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 31% and peaks near 38% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
126
225
325
425
525
625
725
826
926
1027
1127
1228
1329
1430
1530
1631
1732
1833
1933
2034
2135
2235
2335
2436
2536
2637
2737
2838
2938
3038

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 62% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
14940101
2513991
3523891
4523891
5543781
6563680
7563680
8573580
9573580
10593470
11593470
12603370
13613360
14623260
15633250
16643150
17643150
18663040
19663040
20663040
21672940
22682930
23682930
24682930
25682930
26682930
27692830
28702820
29712720
30712720

Wind in September

Winds average 14 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 6:33 AM to 7:15 AM, and sunset from 7:48 PM to 6:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.26:337:48
213.26:357:46
313.16:367:44
413.16:387:42
513.06:397:40
613.06:407:38
712.96:427:35
812.86:437:33
912.86:457:31
1012.76:467:29
1112.76:487:27
1212.66:497:25
1312.56:517:22
1412.56:527:20
1512.46:537:18
1612.36:557:16
1712.36:567:14
1812.26:587:11
1912.26:597:09
2012.17:017:07
2112.07:027:05
2212.07:047:03
2311.97:057:01
2411.97:076:58
2511.87:086:56
2611.77:106:54
2711.77:116:52
2811.67:126:50
2911.67:146:47
3011.57:156:45

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.64 kWh/m².

For context, solar energy here swings from a low near 0.88 kWh/m² to a high of 5.86 kWh/m² in June across the year — September's 3.64 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.2Bright
44.2Bright
54.2Bright
64.1Bright
74.1Bright
84.0Bright
94.0Moderate
103.9Moderate
113.9Moderate
123.8Moderate
133.8Moderate
143.7Moderate
153.7Moderate
163.6Moderate
173.5Moderate
183.5Moderate
193.4Moderate
203.4Moderate
213.3Moderate
223.3Moderate
233.2Moderate
243.1Moderate
253.1Moderate
263.0Moderate
273.0Moderate
282.9Moderate
292.9Moderate
302.8Moderate
Planning a trip in September

Is September a good time to visit Saint-Brieuc?

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

6.1
Sightseeing
3rd-best month of the year
2.7
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Saint-Brieuc for sightseeing.

What to pack for Saint-Brieuc in September

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

In September, Saint-Brieuc sees daytime highs around 19°C and nights near 12°C. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Saint-Brieuc in September

The nearest coast averages about 18°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 16 km away) is warmest in August at about 18°C and coldest in February near 9°C.

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

10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan10Bracing
Feb9Bracing
Mar9Bracing
Apr10Bracing
May12Bracing
Jun14Bracing
Jul16Cool
Aug18Cool
Sep18Cool
Oct16Cool
Nov14Bracing
Dec12Bracing

UV index in Saint-Brieuc in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Saint-Brieuc peaks around June 19 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 19UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May6High
Jun7High
Jul7High
Aug7High
Sep5Moderate
Oct3Moderate
Nov1Low
Dec1Low
Location & terrain

Where is Saint-Brieuc?

Saint-Brieuc sits at 48.5°N, 2.8°W, 96 m above sea level, in France. The nearest listed city is Pontivy, 52 km away.

Topography around Saint-Brieuc

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

Within 3 km, the terrain around Saint-Brieuc has only modest variations in elevation — a maximum elevation change of 141 m around an average of 92 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 275 m; within 80 km, significant variations in elevation — a maximum elevation change of 364 m.

The land around Saint-Brieuc is covered by artificial surfaces (41%) and trees (39%) within 3 km, trees (28%), cropland (28%) and water (23%) within 16 km, and water (33%), cropland (28%) and trees (24%) within 80 km.

3 km
141 m
16 km
275 m
80 km
364 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Pontivy 52 km · Lannion 56 km · Saint-Malo 58 km · Morlaix 78 km · Saint Helier 89 km · Rennes 93 km · Lanester 94 km · Vannes 95 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 Saint-Brieuc (48.5151°, -2.7684°, elevation 96 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).