Climate and average weather in Saint-Brieuc

In Saint-Brieuc, the summers are mild, showery, and partly cloudy and the winters are cool and mostly cloudy.

Best: late May to late September

Over the course of the year, the temperature in Saint-Brieuc typically varies from 4°C to 21°C, and is rarely below -2°C or above 25°C. August is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Saint-Brieuc for warm-weather activities is from late May to late September.

Hottest
Aug
21°
Coldest
Jan
Wettest
Dec
71 mm
Driest
Jul
46 mm
Rain / yr
685 mm
131 wet days
Daylight
8.1–15.9 h
shortest–longest
Elevation
96 m
48.5°N
Clearest
Jul
63% cloud
Air quality
Good
PM10 15.4 µg/m³ · 2019

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

Saint-Brieuc weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late May to late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Saint-Brieuc, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 3.5 months, from June 9 to September 23, with daily high temperatures above 18°C. The hottest month of the year in Saint-Brieuc is August, with an average high of 21°C and low of 14°C.

The cool season lasts 3.6 months, from November 21 to March 11, with daily high temperatures below 11°C. The coldest month of the year in Saint-Brieuc is January, with an average low of 4°C and high of 9°C.

Days typically run about 6°C warmer than nights, with the widest day–night swing (around 8°C) in July.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan94
Feb94
Mar115
Apr136
May169
Jun1912
Jul2113
Aug2114
Sep1912
Oct1610
Nov127
Dec95

How hot and cold Saint-Brieuc really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about -0°C (around January 29), with roughly 26 freezing days a year (feels-like at or below 0°C), worst in January.

-5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan9904
Feb9904
Mar111125
Apr131336
May161679
Jun19191212
Jul21211313
Aug21211414
Sep19191212
Oct1616810
Nov121247
Dec9915

Average hourly temperature in Saint-Brieuc

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on August afternoons, near 21°C, and coldest before dawn in January, near C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Saint-Brieuc weather by month

Every month at a glance. Click a month for its detailed page.

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

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Saint-Brieuc gets about 685 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.0 months, from around Sep 25 to Jan 24, peaking in November at about 43% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Sep 4.

December is the wettest month by volume, with 71 mm over about 13 wet days; July is the driest, with 46 mm.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwettermostly drysome rainoften wetvery wetNov 30 · 43%Sep 4 · 26%
Rain on a day (%)Rain days
Jan3711
Feb3911
Mar3411
Apr3912
May3711
Jun3310
Jul299
Aug3010
Sep319
Oct3912
Nov4213
Dec4213

Monthly rainfall

Over a full year, Saint-Brieuc collects about 685 mm of rain across 131 wet days — roughly 57 mm in an average month.

It doesn’t fall evenly. December is the wettest month with 71 mm, while July is the driest at just 46 mm. The three wettest months alone bring about 30% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100JanFebMarAprMayJunJulAugSepOctNovDec605351576256464948686471
Rainfall (mm)Rain daysSnow days
Jan60110
Feb53111
Mar51110
Apr57120
May62110
Jun56100
Jul4690
Aug49100
Sep4890
Oct68120
Nov64130
Dec71131

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Saint-Brieuc, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around May 18 and lasts for 4.3 months, ending around September 26. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 42% of the time on average.

The cloudier part of the year begins around September 27 and lasts for 5.9 months, ending around March 26. The cloudiest month is January, when it is overcast or mostly cloudy 74% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecSep 6 · 44%Jan 20 · 26%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2674
Feb2971
Mar3070
Apr3565
May3268
Jun3763
Jul4258
Aug4060
Sep3961
Oct3268
Nov2971
Dec2971

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 13, brings about 15 h 54 min of light; the shortest, around December 13, only 8 h 06 min — a swing of roughly 7 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan8.69:055:36
Feb9.98:306:22
Mar11.67:347:08
Apr13.46:297:54
May15.05:378:37
Jun15.85:159:08
Jul15.55:319:03
Aug14.16:108:20
Sep12.46:557:16
Oct10.67:406:12
Nov9.08:285:24
Dec8.29:045:11

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Saint-Brieuc averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 7 days.

The sunnier stretch runs 4.6 months, from around May 13 to Sep 28. The sunniest month is July, with roughly 7 sunny days (gloomy).

The greyest month is November, down near 4 sunny days — about 48% fewer than the July peak.

0510JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedJul 187 daysNov 253 days
Sunny daysSky
Jan4Gloomy
Feb4Gloomy
Mar5Gloomy
Apr6Gloomy
May6Gloomy
Jun6Gloomy
Jul7Gloomy
Aug7Gloomy
Sep6Gloomy
Oct5Gloomy
Nov4Gloomy
Dec4Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Saint-Brieuc, how humid it feels changes noticeably over the year.

The more humid part of the year lasts 3.2 months, from around June 16 to September 21. The muggiest month is August, when the air feels humid, muggy or worse about 19% of the time.

The most comfortable stretch runs from around September 22 to June 15, and April is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecApr 21 · 100%Aug 7 · 78%humidcomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)
Jan100000
Feb100000
Mar100000
Apr100000
May93700
Jun712540
Jul3749130
Aug3547171
Sep623260
Oct821710
Nov97300
Dec100000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Saint-Brieuc is typically light breeze, near 16 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.9 months, from around Oct 11 to Apr 9. The windiest month is January, averaging about 18 km/h (light breeze).

The calmer part of the year runs from around Apr 10 to Oct 10, with August the calmest month at about 13 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyJan 6 · 19 km/hAug 3 · 13 km/h
Wind speed (km/h)Feels
Jan18light breeze
Feb18light breeze
Mar17light breeze
Apr16light breeze
May15light breeze
Jun14light breeze
Jul13light breeze
Aug13light breeze
Sep15light breeze
Oct16light breeze
Nov17light breeze
Dec18light breeze

Best time to visit Saint-Brieuc

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Saint-Brieuc throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late September, Saint-Brieuc is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Saint-Brieuc for general outdoor tourist activities is from late May to late September, with a peak score in the third week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 20 · 6.7

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan1.6poor
Feb1.8poor
Mar2.7poor
Apr3.6fair
May4.9fair
Jun6.0good
Jul6.6good
Aug6.6good
Sep6.1good
Oct4.5fair
Nov2.8poor
Dec1.8poor

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Saint-Brieuc for hot-weather activities is from early July to early September, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 29 · 4.4

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Saint-Brieuc, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around August (highs near 21°C), the essentials are rain gear and sun protection. In the cold season around January (highs near 9°C), pack a warm layer and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Saint-Brieuc sees daytime highs around 21°C and nights near 14°C. Worth packing: rain gear and sun protection. About 10 days see rain.

Sea temperature near Saint-Brieuc

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

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 (midday) in Saint-Brieuc by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

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

Average hourly UV index in Saint-Brieuc

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 3.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar10
Apr5.50
May70
Jun83.5
Jul7.52.5
Aug73
Sep50
Oct00
Nov00
Dec00
Almanac & agriculture

Growing season

Chance of a frost-free dayReliably frost-free (≥90%)

Saint-Brieuc is mild enough that a frost-free day stays more likely than not even in midwinter. Nights are reliably above freezing from about February 25 to December 12 (291 days); outside that window a hard frost is an occasional risk.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecreliably frost-freeFeb 2590%Dec 1290%
Frost-free chance (%)Frost nights
Jan8631
Feb8828
Mar961
Apr990
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov980
Dec8925

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Saint-Brieuc banks about 952 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

02004006008001,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr8
May81
Jun159
Jul224
Aug229
Sep164
Oct83
Nov5
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Saint-Brieuc receives about 3.4 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.9 and 5.9 kWh/m².

The brighter stretch of the year lasts 6.0 months, from around Mar 22 to Sep 20. The brightest month is June, averaging about 5.8 kWh/m² (bright).

The dimmest month is December, down near 0.9 kWh/m² — roughly 85% less than the June peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 215.9 kWhDec 220.9 kWh
Solar energy (kWh/m²)Level
Jan1.0Dim
Feb1.9Dim
Mar3.1Moderate
Apr4.6Bright
May5.4Bright
Jun5.9Bright
Jul5.7Bright
Aug4.8Bright
Sep3.6Moderate
Oct2.1Moderate
Nov1.3Dim
Dec0.9Dim

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
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).