Climate and average weather in Coleraine

In Coleraine, the summers are cool, wet, and mostly cloudy and the winters are cold, windy, snowy, and mostly cloudy.

Best: late June to early October

Over the course of the year, the temperature in Coleraine typically varies from 5°C to 15°C, and is rarely below 3°C or above 17°C. August is the hottest month of the year, while February is the coldest.

Based on the travel score, the best time of year to visit Coleraine for warm-weather activities is from late June to early October.

Hottest
Aug
15°
Coldest
Feb
Wettest
Nov
149 mm
Driest
May
71 mm
Rain / yr
1283 mm
203 wet days
Daylight
6.9–17.1 h
shortest–longest
Elevation
5 m
55.1°N
Clearest
May
66% cloud

Coleraine is town and civil parish in County Londonderry, Northern Ireland.

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

Coleraine 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 June to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Coleraine stay fairly even through the year, without a distinct hot or cool season. The warmest month is August, with an average high of 15°C and low of 13°C; the coolest is February, with an average low of 5°C and high of 8°C.

Days typically run about 2°C warmer than nights year-round.

10°15°20°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan86
Feb85
Mar86
Apr97
May119
Jun1311
Jul1413
Aug1513
Sep1412
Oct1210
Nov108
Dec96

Average hourly temperature in Coleraine

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 15°C, and coldest before dawn in February, near C.

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

Coleraine 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 / 12420.30.67.51.0
Feb / 10016.919.20.9
Mar / 91160.811.41.1
Apr / 7813.90.213.81.6
May11° / 7113.4015.82.3
Jun13° / 11°8614.60172.9
Jul14° / 13°9516.1016.53.5
Aug15° / 13°10416.2014.73.7
Sep14° / 12°10116.3012.53.5
Oct12° / 10°13918.9010.22.6
Nov10° / 14920.80.28.11.7
Dec / 147200.771.3

Chance of rain

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

Coleraine gets about 1283 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.5 months, from around Sep 25 to Mar 9, peaking in November at about 71% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Apr 18.

November is the wettest month by volume, with 149 mm over about 21 wet days; May is the driest, with 71 mm.

0%10%20%30%40%50%60%70%80%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetNov 10 · 71%Apr 18 · 43%
Rain on a day (%)Rain days
Jan6520
Feb6017
Mar5216
Apr4514
May4413
Jun4815
Jul5216
Aug5316
Sep5416
Oct6119
Nov6921
Dec6520

Monthly rainfall

Over a full year, Coleraine collects about 1283 mm of rain across 203 wet days — roughly 107 mm in an average month.

It doesn’t fall evenly. November is the wettest month with 149 mm, while May is the driest at just 71 mm. The three wettest months alone bring about 34% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100125150175JanFebMarAprMayJunJulAugSepOctNovDec1241009178718695104101139149147
Rainfall (mm)Rain daysSnow days
Jan124201
Feb100171
Mar91161
Apr78140
May71130
Jun86150
Jul95160
Aug104160
Sep101160
Oct139190
Nov149210
Dec147201

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Coleraine, 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 March 29 and lasts for 3.3 months, ending around July 5. The clearest month is May, when the sky is clear, mostly clear, or partly cloudy 38% of the time on average.

The cloudier part of the year begins around September 28 and lasts for 6.0 months, ending around March 28. The cloudiest month is January, when it is overcast or mostly cloudy 78% 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%JanFebMarAprMayJunJulAugSepOctNovDecMay 7 · 42%Jan 27 · 20%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2278
Feb2377
Mar2575
Apr3466
May3862
Jun3070
Jul2575
Aug2773
Sep2773
Oct2575
Nov2476
Dec2377

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 14, brings about 17 h 06 min of light; the shortest, around December 14, only 6 h 54 min — a swing of roughly 10 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan7.58:524:20
Feb9.28:035:19
Mar11.46:536:20
Apr13.85:327:21
May15.84:268:19
Jun17.03:549:00
Jul16.54:148:50
Aug14.75:087:54
Sep12.56:086:34
Oct10.27:075:16
Nov8.18:114:13
Dec7.08:563:50

Sunny days

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

Coleraine averages about 3 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 7 days.

The sunnier stretch runs 3.9 months, from around Mar 14 to Jul 11. The sunniest month is May, with roughly 6 sunny days (gloomy).

The greyest month is January, down near 2 sunny days — about 64% fewer than the May peak.

0510JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedMay 57 daysJan 272 days
Sunny daysSky
Jan2Gloomy
Feb3Gloomy
Mar3Gloomy
Apr5Gloomy
May6Gloomy
Jun4Gloomy
Jul3Gloomy
Aug3Gloomy
Sep3Gloomy
Oct2Gloomy
Nov2Gloomy
Dec2Gloomy

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 Coleraine, the air stays dry or comfortable essentially all year. Even in September, the muggiest month, it feels humid or worse only about 0% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDeccomfortabledry
Dry (%)Comfortable (%)
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun991
Jul8614
Aug7624
Sep8911
Oct991
Nov1000
Dec1000

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 Coleraine is typically breezy, near 26 km/h, and varies a lot with the seasons.

The windier part of the year lasts 6.1 months, from around Sep 27 to Apr 1. The windiest month is January, averaging about 32 km/h (windy).

The calmer part of the year runs from around Apr 2 to Sep 26, with July the calmest month at about 20 km/h.

0510152025303540JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezywindyblusteryJan 9 · 33 km/hJul 21 · 20 km/h
Wind speed (km/h)Feels
Jan32windy
Feb31windy
Mar29breezy
Apr25breezy
May22breezy
Jun21breezy
Jul20light breeze
Aug21breezy
Sep25breezy
Oct29breezy
Nov31windy
Dec32windy

Best time to visit Coleraine

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around early July, Coleraine is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

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 Coleraine for general outdoor tourist activities is from late June to early October, with a peak score in the last week of August.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationAug 26 · 3.8

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
Jan1.0poor
Feb0.9poor
Mar1.1poor
Apr1.6poor
May2.3poor
Jun2.9poor
Jul3.5poor
Aug3.7fair
Sep3.5poor
Oct2.6poor
Nov1.7poor
Dec1.3poor

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Coleraine rarely gets warm enough to lift this score — no time of year really suits hot-weather activities here.

024681012JanFebMarAprMayJunJulAugSepOctNovDectemperaturecloudsprecipitation

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 Coleraine, 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 15°C), the essentials are a warm layer, rain gear and a windbreaker. In the cold season around February (highs near 8°C), pack a warm layer, a heavy coat, rain gear and a windbreaker.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Coleraine sees daytime highs around 15°C and nights near 13°C. Pack rain gear. Worth having: a warm layer and a windbreaker. About 16 days see rain.

Sea temperature near Coleraine

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 27 km away) is warmest in September at about 14°C and coldest in March near 8°C.

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

6°8°10°12°14°16°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan9Bracing
Feb8Bracing
Mar8Bracing
Apr8Bracing
May9Bracing
Jun11Bracing
Jul13Bracing
Aug14Bracing
Sep14Bracing
Oct13Bracing
Nov12Bracing
Dec10Bracing

UV index (midday) in Coleraine 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 Coleraine peaks around July 12 at about 5 (high) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 5 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJul 12UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Moderate
Apr3Moderate
May5High
Jun5Moderate
Jul5High
Aug4Moderate
Sep3Moderate
Oct2Low
Nov1Low
Dec0Low

Average hourly UV index in Coleraine

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 May the burn window is concentrated in the middle of the day: about 6.5 hours a day reach index 3 (protection recommended). 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
Mar00
Apr00
May6.50
Jun6.50
Jul6.50
Aug5.50
Sep1.50
Oct00
Nov00
Dec00
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Coleraine is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

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. Coleraine banks about 427 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

0200400600JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr0
May4
Jun50
Jul105
Aug125
Sep98
Oct45
Nov1
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.

Coleraine receives about 2.6 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.4 and 5.2 kWh/m².

The brighter stretch of the year lasts 5.8 months, from around Mar 23 to Sep 15. The brightest month is June, averaging about 5.0 kWh/m² (bright).

The dimmest month is December, down near 0.4 kWh/m² — roughly 91% less than the June peak.

0123456JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightJun 25.2 kWhDec 210.4 kWh
Solar energy (kWh/m²)Level
Jan0.6Dim
Feb1.3Dim
Mar2.3Moderate
Apr3.9Moderate
May5.0Bright
Jun5.0Bright
Jul4.5Bright
Aug3.8Moderate
Sep2.6Moderate
Oct1.5Dim
Nov0.7Dim
Dec0.4Dim

Where is Coleraine?

Coleraine sits at 55.1°N, 6.7°W, 5 m above sea level, in United Kingdom. The nearest listed city is Ballymena, 39 km away.

LetterkennyNewtownabbeyOmagh

Topography around Coleraine

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

Within 3 km, the terrain around Coleraine has only modest variations in elevation — a maximum elevation change of 82 m around an average of 30 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 385 m; within 80 km, large variations in elevation — a maximum elevation change of 675 m.

The land around Coleraine is covered by grassland (54%) and trees (22%) within 3 km, grassland (57%) and water (24%) within 16 km, and grassland (46%) and water (46%) within 80 km.

3 km
82 m
16 km
385 m
80 km
675 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Ballymena 39 km · Derry 44 km · Londonderry County Borough 44 km · Antrim 55 km · Larne 63 km · Letterkenny 71 km · Newtownabbey 72 km · Omagh 72 km

United Kingdom travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type D / G / M
230 V · 50 Hz
Prices
≈ 89% of US
price level, 2025
GDP per capita
$57,602
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2021
Road deaths
3.2
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 60%none 26%Muslim 4%other 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 Coleraine (55.1333°, -6.6667°, elevation 5 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).