Carrickfergus weather in September

In September, Carrickfergus sees average daytime highs of 15°C and overnight lows near 12°C, with 86 mm of rain across 13.8 wet days and about 12.5 hours of daylight. It is the 3rd-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 15°C through the month. The sky is clear or mostly clear about 11% 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 Carrickfergus's 4th-clearest and 8th-windiest month. For the whole year in context, see Carrickfergus's year-round climate.

Daytime high: 15°; 3rd warmest
Overnight low: 12°; 10th coldest
Rainfall: 86 mm; 13.8 wet days
Daylight: 12 h 24 min; 6:04 AM – 6:31 PM
Cloud cover: 74%; 4th clearest
Wind: 20 km/h; 8th windiest
Solar energy: 2.76 kWh/m²
Travel score: 3.8; out of 10

Carrickfergus is town in County Antrim, Northern Ireland.

Density: 2,386/km²; people per km²

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

← August Carrickfergus year-round climate October →Best places to visit in September

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 15°C through the month.

A typical September day in Carrickfergus reaches about 15°C in the afternoon and slips back to 12°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 17°C. Set against its neighbours, September runs about 1°C cooler than August and about 2°C warmer than October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	14	14	14	14	14	14	14	14	14	14	14	14
Avg low (°C)	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	11	11	11	11	11	11	11	11	11	11	11

	Avg high (°C)	Avg low (°C)
1	15	12
2	15	12
3	15	12
4	15	12
5	15	12
6	15	12
7	15	12
8	15	12
9	15	12
10	15	12
11	15	12
12	15	12
13	15	12
14	15	12
15	15	12
16	15	12
17	15	12
18	15	12
19	14	12
20	14	11
21	14	11
22	14	11
23	14	11
24	14	11
25	14	11
26	14	11
27	14	11
28	14	11
29	14	11
30	14	11

How September really feels in Carrickfergus

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

heat index over the day's high

Days feeling ≤ 0°C

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.

Carrickfergus weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 7th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	8° / 5°	99	17.2	0.8	7.6	0.9
Feb	7° / 5°	79	14	1	9.3	0.9
Mar	8° / 5°	76	14.6	0.7	11.5	1.2
Apr	10° / 6°	68	13.4	0.2	13.7	1.8
May	12° / 8°	72	13.5	0	15.8	2.7
Jun	14° / 11°	82	13.7	0	16.9	3.5
Jul	15° / 12°	94	15.4	0	16.5	4.0
Aug	16° / 13°	92	15.1	0	14.7	4.2
Sep	15° / 12°	86	13.8	0	12.5	3.8
Oct	12° / 10°	114	16.2	0	10.2	2.8
Nov	10° / 7°	113	17.3	0.1	8.2	1.8
Dec	8° / 5°	109	15.7	0.4	7.1	1.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 11% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 72%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	28	28	28	27	27	28	28	28	28	28	29	29	29	29	29	29	29	28	29	29	28	28	27	27	26	26	26	25	26	26
Cloudier (%)	72	72	72	73	73	72	72	72	72	72	71	71	71	71	71	71	71	72	71	71	72	72	73	73	74	74	74	75	74	74

	Clearer (%)	Cloudier (%)
1	28	72
2	28	72
3	28	72
4	27	73
5	27	73
6	28	72
7	28	72
8	28	72
9	28	72
10	28	72
11	29	71
12	29	71
13	29	71
14	29	71
15	29	71
16	29	71
17	29	71
18	28	72
19	29	71
20	29	71
21	28	72
22	28	72
23	27	73
24	27	73
25	26	74
26	26	74
27	26	74
28	25	75
29	26	74
30	26	74

Chance of precipitation in September

Any precipitation

Carrickfergus gets around 86 mm of rain over 13.8 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 46% and peaks near 51% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	44	44	45	45	45	46	46	47	47	47	47	47	47	46	46	46	45	45	45	45	45	45	46	46	47	48	49	50	51	51

	Rain chance (%)
1	44
2	44
3	45
4	45
5	45
6	46
7	46
8	47
9	47
10	47
11	47
12	47
13	47
14	46
15	46
16	46
17	45
18	45
19	45
20	45
21	45
22	45
23	46
24	46
25	47
26	48
27	49
28	50
29	51
30	51

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 88% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	81	82	82	83	83	83	84	85	85	86	87	87	88	88	89	89	89	90	90	90	91	91	91	91	92	92	92	93	93	94
Comfortable (%)	19	18	18	17	17	17	16	15	15	14	13	13	12	12	11	11	11	10	10	10	9	9	9	9	8	8	8	7	7	6

	Dry (%)	Comfortable (%)
1	81	19
2	82	18
3	82	18
4	83	17
5	83	17
6	83	17
7	84	16
8	85	15
9	85	15
10	86	14
11	87	13
12	87	13
13	88	12
14	88	12
15	89	11
16	89	11
17	89	11
18	90	10
19	90	10
20	90	10
21	91	9
22	91	9
23	91	9
24	91	9
25	92	8
26	92	8
27	92	8
28	93	7
29	93	7
30	94	6

Wind in September

Winds average 20 km/h in September.

Across September, daily wind ranges from about 18 km/h on the calmest days to 21 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	18	19	19	19	19	19	19	19	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	21	21	21	21	21
Feels	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy

	Wind speed (km/h)	Feels
1	18	light breeze
2	19	light breeze
3	19	light breeze
4	19	light breeze
5	19	light breeze
6	19	light breeze
7	19	light breeze
8	19	light breeze
9	20	light breeze
10	20	light breeze
11	20	light breeze
12	20	light breeze
13	20	light breeze
14	20	light breeze
15	20	light breeze
16	20	light breeze
17	20	light breeze
18	20	light breeze
19	20	breezy
20	20	breezy
21	20	breezy
22	20	breezy
23	20	breezy
24	20	breezy
25	20	breezy
26	21	breezy
27	21	breezy
28	21	breezy
29	21	breezy
30	21	breezy

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 5:36 AM to 6:31 AM, and sunset from 7:10 PM to 5:54 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	13.6	13.5	13.4	13.3	13.3	13.2	13.1	13.0	13.0	12.9	12.8	12.7	12.7	12.6	12.5	12.4	12.4	12.3	12.2	12.1	12.1	12.0	11.9	11.8	11.8	11.7	11.6	11.5	11.4	11.4
Sunrise (AM)	5:36	5:38	5:40	5:42	5:44	5:45	5:47	5:49	5:51	5:53	5:55	5:57	5:59	6:01	6:03	6:04	6:06	6:08	6:10	6:12	6:14	6:16	6:18	6:20	6:22	6:24	6:26	6:27	6:29	6:31
Sunset (PM)	7:10	7:07	7:05	7:02	7:00	6:57	6:54	6:52	6:49	6:47	6:44	6:41	6:39	6:36	6:33	6:31	6:28	6:25	6:23	6:20	6:17	6:15	6:12	6:09	6:07	6:04	6:02	5:59	5:56	5:54

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	13.6	5:36	7:10
2	13.5	5:38	7:07
3	13.4	5:40	7:05
4	13.3	5:42	7:02
5	13.3	5:44	7:00
6	13.2	5:45	6:57
7	13.1	5:47	6:54
8	13.0	5:49	6:52
9	13.0	5:51	6:49
10	12.9	5:53	6:47
11	12.8	5:55	6:44
12	12.7	5:57	6:41
13	12.7	5:59	6:39
14	12.6	6:01	6:36
15	12.5	6:03	6:33
16	12.4	6:04	6:31
17	12.4	6:06	6:28
18	12.3	6:08	6:25
19	12.2	6:10	6:23
20	12.1	6:12	6:20
21	12.1	6:14	6:17
22	12.0	6:16	6:15
23	11.9	6:18	6:12
24	11.8	6:20	6:09
25	11.8	6:22	6:07
26	11.7	6:24	6:04
27	11.6	6:26	6:02
28	11.5	6:27	5:59
29	11.4	6:29	5:56
30	11.4	6:31	5:54

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.76 kWh/m².

For context, solar energy here swings from a low near 0.46 kWh/m² to a high of 5.1 kWh/m² in June across the year — September's 2.76 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	3.4	3.3	3.3	3.2	3.2	3.1	3.1	3.1	3.0	3.0	3.0	2.9	2.9	2.9	2.8	2.8	2.7	2.7	2.6	2.6	2.6	2.5	2.5	2.4	2.4	2.3	2.3	2.2	2.2	2.1
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	3.4	Moderate
2	3.3	Moderate
3	3.3	Moderate
4	3.2	Moderate
5	3.2	Moderate
6	3.1	Moderate
7	3.1	Moderate
8	3.1	Moderate
9	3.0	Moderate
10	3.0	Moderate
11	3.0	Moderate
12	2.9	Moderate
13	2.9	Moderate
14	2.9	Moderate
15	2.8	Moderate
16	2.8	Moderate
17	2.7	Moderate
18	2.7	Moderate
19	2.6	Moderate
20	2.6	Moderate
21	2.6	Moderate
22	2.5	Moderate
23	2.5	Moderate
24	2.4	Moderate
25	2.4	Moderate
26	2.3	Moderate
27	2.3	Moderate
28	2.2	Moderate
29	2.2	Moderate
30	2.1	Moderate

Planning a trip in September

Is September a good time to visit Carrickfergus?

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

3.8

Sightseeing

3rd-best month of the year

—

Beach & pool

never really warm enough

September is a weaker month for outdoor sightseeing in Carrickfergus.

What to pack for Carrickfergus in September

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

In September, Carrickfergus sees daytime highs around 15°C and nights near 12°C. Pack rain gear. Worth having: a warm layer. About 14 days see rain.

rain geara warm layer

Sea temperature near Carrickfergus 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 18 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.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	9	8	8	8	9	11	12	13	14	14	12	11
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	9	Bracing
Feb	8	Bracing
Mar	8	Bracing
Apr	8	Bracing
May	9	Bracing
Jun	11	Bracing
Jul	12	Bracing
Aug	13	Bracing
Sep	14	Bracing
Oct	14	Bracing
Nov	12	Bracing
Dec	11	Bracing

UV index in Carrickfergus 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 Carrickfergus 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.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	0	1	2	3	5	5	5	5	3	2	1	0
Level	Low	Low	Moderate	Moderate	High	High	High	Moderate	Moderate	Low	Low	Low

	UV index (midday)	Level
Jan	0	Low
Feb	1	Low
Mar	2	Moderate
Apr	3	Moderate
May	5	High
Jun	5	High
Jul	5	High
Aug	5	Moderate
Sep	3	Moderate
Oct	2	Low
Nov	1	Low
Dec	0	Low

Location & terrain

Where is Carrickfergus?

Carrickfergus sits at 54.7°N, 5.8°W, 7 m above sea level, in United Kingdom. The nearest listed city is Newtownabbey, 9.0 km away.

Topography around Carrickfergus

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

Within 3 km, the terrain around Carrickfergus has only modest variations in elevation — a maximum elevation change of 171 m around an average of 25 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 447 m; within 80 km, large variations in elevation — a maximum elevation change of 860 m.

The land around Carrickfergus is covered by water (47%) and grassland (25%) within 3 km, grassland (46%) and water (30%) within 16 km, and water (49%) and grassland (43%) within 80 km.

3 km

171 m

water 47%

16 km

447 m

grassland 46%

80 km

860 m

water 49%

treesgrasslandcroplandartificial surfaceswater

← August Carrickfergus year-round climate October →Best places to visit in September

September weather nearby: Newtownabbey 9.0 km · Bangor 11 km · Larne 15 km · Belfast 15 km · Newtownards 16 km · Castlereagh 17 km · Lisburn 26 km · Antrim 26 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

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 Carrickfergus (54.7158°, -5.8058°, elevation 7 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).

	Avg high (°C)	Avg low (°C)
1	15	12
2	15	12
3	15	12
4	15	12
5	15	12
6	15	12
7	15	12
8	15	12
9	15	12
10	15	12
11	15	12
12	15	12
13	15	12
14	15	12
15	15	12
16	15	12
17	15	12
18	15	12
19	14	12
20	14	11
21	14	11
22	14	11
23	14	11
24	14	11
25	14	11
26	14	11
27	14	11
28	14	11
29	14	11
30	14	11

	Clearer (%)	Cloudier (%)
1	28	72
2	28	72
3	28	72
4	27	73
5	27	73
6	28	72
7	28	72
8	28	72
9	28	72
10	28	72
11	29	71
12	29	71
13	29	71
14	29	71
15	29	71
16	29	71
17	29	71
18	28	72
19	29	71
20	29	71
21	28	72
22	28	72
23	27	73
24	27	73
25	26	74
26	26	74
27	26	74
28	25	75
29	26	74
30	26	74

	Rain chance (%)
1	44
2	44
3	45
4	45
5	45
6	46
7	46
8	47
9	47
10	47
11	47
12	47
13	47
14	46
15	46
16	46
17	45
18	45
19	45
20	45
21	45
22	45
23	46
24	46
25	47
26	48
27	49
28	50
29	51
30	51

	Dry (%)	Comfortable (%)
1	81	19
2	82	18
3	82	18
4	83	17
5	83	17
6	83	17
7	84	16
8	85	15
9	85	15
10	86	14
11	87	13
12	87	13
13	88	12
14	88	12
15	89	11
16	89	11
17	89	11
18	90	10
19	90	10
20	90	10
21	91	9
22	91	9
23	91	9
24	91	9
25	92	8
26	92	8
27	92	8
28	93	7
29	93	7
30	94	6

	Avg high (°C)	Avg low (°C)
1	15	12
2	15	12
3	15	12
4	15	12
5	15	12
6	15	12
7	15	12
8	15	12
9	15	12
10	15	12
11	15	12
12	15	12
13	15	12
14	15	12
15	15	12
16	15	12
17	15	12
18	15	12
19	14	12
20	14	11
21	14	11
22	14	11
23	14	11
24	14	11
25	14	11
26	14	11
27	14	11
28	14	11
29	14	11
30	14	11

	Clearer (%)	Cloudier (%)
1	28	72
2	28	72
3	28	72
4	27	73
5	27	73
6	28	72
7	28	72
8	28	72
9	28	72
10	28	72
11	29	71
12	29	71
13	29	71
14	29	71
15	29	71
16	29	71
17	29	71
18	28	72
19	29	71
20	29	71
21	28	72
22	28	72
23	27	73
24	27	73
25	26	74
26	26	74
27	26	74
28	25	75
29	26	74
30	26	74

	Rain chance (%)
1	44
2	44
3	45
4	45
5	45
6	46
7	46
8	47
9	47
10	47
11	47
12	47
13	47
14	46
15	46
16	46
17	45
18	45
19	45
20	45
21	45
22	45
23	46
24	46
25	47
26	48
27	49
28	50
29	51
30	51

	Dry (%)	Comfortable (%)
1	81	19
2	82	18
3	82	18
4	83	17
5	83	17
6	83	17
7	84	16
8	85	15
9	85	15
10	86	14
11	87	13
12	87	13
13	88	12
14	88	12
15	89	11
16	89	11
17	89	11
18	90	10
19	90	10
20	90	10
21	91	9
22	91	9
23	91	9
24	91	9
25	92	8
26	92	8
27	92	8
28	93	7
29	93	7
30	94	6

	Avg high (°C)	Avg low (°C)
1	15	12
2	15	12
3	15	12
4	15	12
5	15	12
6	15	12
7	15	12
8	15	12
9	15	12
10	15	12
11	15	12
12	15	12
13	15	12
14	15	12
15	15	12
16	15	12
17	15	12
18	15	12
19	14	12
20	14	11
21	14	11
22	14	11
23	14	11
24	14	11
25	14	11
26	14	11
27	14	11
28	14	11
29	14	11
30	14	11

	Clearer (%)	Cloudier (%)
1	28	72
2	28	72
3	28	72
4	27	73
5	27	73
6	28	72
7	28	72
8	28	72
9	28	72
10	28	72
11	29	71
12	29	71
13	29	71
14	29	71
15	29	71
16	29	71
17	29	71
18	28	72
19	29	71
20	29	71
21	28	72
22	28	72
23	27	73
24	27	73
25	26	74
26	26	74
27	26	74
28	25	75
29	26	74
30	26	74

	Rain chance (%)
1	44
2	44
3	45
4	45
5	45
6	46
7	46
8	47
9	47
10	47
11	47
12	47
13	47
14	46
15	46
16	46
17	45
18	45
19	45
20	45
21	45
22	45
23	46
24	46
25	47
26	48
27	49
28	50
29	51
30	51

	Dry (%)	Comfortable (%)
1	81	19
2	82	18
3	82	18
4	83	17
5	83	17
6	83	17
7	84	16
8	85	15
9	85	15
10	86	14
11	87	13
12	87	13
13	88	12
14	88	12
15	89	11
16	89	11
17	89	11
18	90	10
19	90	10
20	90	10
21	91	9
22	91	9
23	91	9
24	91	9
25	92	8
26	92	8
27	92	8
28	93	7
29	93	7
30	94	6