Antrim weather in September

In September, Antrim sees average daytime highs of 16°C and overnight lows near 10°C, with 67 mm of rain across 12.7 wet days and about 12.5 hours of daylight. It is the 4th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 17°C in the first days to 15°C by the end. The sky is clear or mostly clear about 6% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 36 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Antrim's 9th-clearest and 8th-windiest month. For the whole year in context, see Antrim's year-round climate.

Daytime high
16°
4th warmest
Overnight low
10°
9th coldest
Rainfall
67 mm
12.7 wet days
Daylight
12 h 24 min
6:06 AM – 6:32 PM
Cloud cover
79%
9th clearest
Wind
14 km/h
8th windiest
Solar energy
2.69 kWh/m²
Travel score
4.4
out of 10

Antrim is town on the shore of Lough Neagh, in the baronies of Toome Upper and Toome Lower, Co. Antrim, in the northeast of Northern Ireland.

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 17°C in the first days to 15°C by the end.

A typical September day in Antrim reaches about 16°C in the afternoon and slips back to 10°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 19°C. Set against its neighbours, September runs about 2°C cooler than August and about 3°C warmer than October.

10°15°20°151015202530
Avg high (°C)Avg low (°C)
11711
21711
31711
41711
51711
61711
71711
81711
91611
101611
111610
121610
131610
141610
151610
161610
171610
181610
191610
201610
211510
221510
231510
24159
25159
26159
27159
28159
29159
30159

How September really feels in Antrim

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.

Antrim weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 7314.21.47.60.9
Feb / 6112.61.49.31.1
Mar / 6213.90.911.51.7
Apr11° / 6513.70.213.72.6
May14° / 7014.50.115.83.6
Jun17° / 10°7714016.94.5
Jul18° / 12°8214.8016.55.0
Aug18° / 12°8414.8014.74.9
Sep16° / 10°6712.7012.54.4
Oct13° / 8113.8010.23.1
Nov10° / 7713.80.28.21.8
Dec / 7613.10.77.11.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 6% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 80%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12080
21981
31981
41981
51882
61882
71882
81882
91882
101783
111882
121981
131981
141981
151981
162080
172080
182080
192179
202179
212278
222278
232377
242377
252377
262278
272278
282278
292278
302377

Chance of precipitation in September

Any precipitation

Antrim gets around 67 mm of rain over 12.7 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 43% and peaks near 45% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
142
243
343
443
543
644
744
844
944
1044
1144
1243
1343
1443
1542
1642
1741
1841
1941
2040
2140
2241
2341
2442
2543
2643
2744
2845
2945
3045

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 86% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
178202
279192
379192
480182
580182
681172
781172
882162
982162
1084151
1185141
1285141
1386131
1486131
1587121
1688120
1788120
1888120
1988120
2089110
2189110
2289110
2389110
2489110
2590100
2690100
2790100
2890100
299190
309190

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
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 36 min at the start of September to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 132 minutes over September. Sunrise moves from 5:38 AM to 6:33 AM, and sunset from 7:12 PM to 5:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:387:12
213.55:397:09
313.45:417:06
413.35:437:04
513.35:457:01
613.25:476:59
713.15:496:56
813.05:516:53
913.05:536:51
1012.95:556:48
1112.85:576:45
1212.75:586:43
1312.76:006:40
1412.66:026:38
1512.56:046:35
1612.46:066:32
1712.46:086:30
1812.36:106:27
1912.26:126:24
2012.16:146:22
2112.16:166:19
2212.06:186:16
2311.96:196:14
2411.86:216:11
2511.86:236:08
2611.76:256:06
2711.66:276:03
2811.56:296:01
2911.46:315:58
3011.46:335:55

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.69 kWh/m².

For context, solar energy here swings from a low near 0.45 kWh/m² to a high of 4.99 kWh/m² in May across the year — September's 2.69 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.3Moderate
23.2Moderate
33.2Moderate
43.1Moderate
53.1Moderate
63.1Moderate
73.0Moderate
83.0Moderate
93.0Moderate
102.9Moderate
112.9Moderate
122.8Moderate
132.8Moderate
142.8Moderate
152.7Moderate
162.7Moderate
172.7Moderate
182.6Moderate
192.6Moderate
202.5Moderate
212.5Moderate
222.5Moderate
232.4Moderate
242.4Moderate
252.3Moderate
262.3Moderate
272.2Moderate
282.2Moderate
292.1Moderate
302.1Moderate
Planning a trip in September

Is September a good time to visit Antrim?

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

4.4
Sightseeing
4th-best month of the year
0.5
Beach & pool
4th-best month of the year

September is a reasonable time to visit Antrim for sightseeing.

What to pack for Antrim in September

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

In September, Antrim sees daytime highs around 16°C and nights near 10°C. Worth packing: a warm layer and rain gear. About 13 days see rain.

a warm layerrain gear

Sea temperature near Antrim in September

The nearest coast averages about 14°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 28 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
Jul12Bracing
Aug13Bracing
Sep14Bracing
Oct14Bracing
Nov12Bracing
Dec11Bracing

UV index in Antrim in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Antrim peaks around May 22 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowMay 22UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Moderate
Apr3Moderate
May5High
Jun5Moderate
Jul5High
Aug5Moderate
Sep3Moderate
Oct2Low
Nov1Low
Dec0Low
Location & terrain

Where is Antrim?

Antrim sits at 54.7°N, 6.2°W, 33 m above sea level, in United Kingdom. The nearest listed city is Ballymena, 17 km away.

Topography around Antrim

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

Within 3 km, the terrain around Antrim has only modest variations in elevation — a maximum elevation change of 117 m around an average of 46 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 363 m; within 80 km, large variations in elevation — a maximum elevation change of 860 m.

The land around Antrim is covered by grassland (46%) and trees (22%) within 3 km, grassland (70%) within 16 km, and grassland (53%) and water (39%) within 80 km.

3 km
117 m
16 km
363 m
80 km
860 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Ballymena 17 km · Newtownabbey 20 km · Belfast 23 km · Lisburn 24 km · Carrickfergus 26 km · Castlereagh 26 km · Larne 29 km · Craigavon 32 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 Antrim (54.7175°, -6.211°, elevation 33 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).