Sligo weather in September

In September, Sligo sees average daytime highs of 16°C and overnight lows near 10°C, with 91 mm of rain across 15 wet days and about 12.5 hours of daylight. It is the 4th-warmest and 10th-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 5% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 30 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Sligo's 9th-clearest and 8th-windiest month. For the whole year in context, see Sligo's year-round climate.

Daytime high: 16°; 4th warmest
Overnight low: 10°; 10th coldest
Rainfall: 91 mm; 15 wet days
Daylight: 12 h 24 min; 6:15 AM – 6:41 PM
Cloud cover: 81%; 9th clearest
Wind: 14 km/h; 8th windiest
Solar energy: 2.65 kWh/m²
Travel score: 4.1; out of 10

Sligo is main town in county Sligo, Ireland.

Density: 668/km²; people per km²

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

← August Sligo 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

Highs ease over the month, from about 17°C in the first days to 15°C by the end.

A typical September day in Sligo 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.

	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)	17	17	17	17	17	17	17	16	16	16	16	16	16	16	16	16	16	16	16	16	15	15	15	15	15	15	15	15	15	15
Avg low (°C)	11	11	11	11	11	11	11	11	10	10	10	10	10	10	10	10	10	10	10	10	9	9	9	9	9	9	9	9	9	9

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

How September really feels in Sligo

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.

Sligo weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	7° / 3°	109	17.6	1.4	7.7	0.9
Feb	8° / 3°	94	15.4	1.3	9.3	1.0
Mar	9° / 4°	91	16.4	0.9	11.5	1.7
Apr	12° / 5°	84	14.9	0.2	13.7	2.6
May	14° / 8°	96	15.1	0	15.7	3.6
Jun	16° / 10°	99	15.5	0	16.8	4.2
Jul	18° / 12°	110	17.9	0	16.4	4.5
Aug	18° / 12°	108	18	0	14.7	4.4
Sep	16° / 10°	91	15	0	12.5	4.1
Oct	13° / 8°	110	16.7	0	10.2	2.9
Nov	10° / 5°	110	17.5	0.1	8.2	1.6
Dec	8° / 3°	114	18.2	0.9	7.2	1.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 5% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 84%.

	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 (%)	15	14	14	14	14	14	14	14	15	15	15	16	16	16	17	17	18	18	18	18	19	19	19	17	17	17	17	17	17	17
Cloudier (%)	85	86	86	86	86	86	86	86	85	85	85	84	84	84	83	83	82	82	82	82	81	81	81	83	83	83	83	83	83	83

	Clearer (%)	Cloudier (%)
1	15	85
2	14	86
3	14	86
4	14	86
5	14	86
6	14	86
7	14	86
8	14	86
9	15	85
10	15	85
11	15	85
12	16	84
13	16	84
14	16	84
15	17	83
16	17	83
17	18	82
18	18	82
19	18	82
20	18	82
21	19	81
22	19	81
23	19	81
24	17	83
25	17	83
26	17	83
27	17	83
28	17	83
29	17	83
30	17	83

Chance of precipitation in September

Any precipitation

Sligo gets around 91 mm of rain over 15 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 50% and peaks near 52% 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 (%)	51	51	51	51	51	52	52	52	52	52	52	51	51	51	50	50	49	49	48	48	48	48	48	49	49	50	51	51	52	52

	Rain chance (%)
1	51
2	51
3	51
4	51
5	51
6	52
7	52
8	52
9	52
10	52
11	52
12	51
13	51
14	51
15	50
16	50
17	49
18	49
19	48
20	48
21	48
22	48
23	48
24	49
25	49
26	50
27	51
28	51
29	52
30	52

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.

	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 (%)	79	79	80	80	80	80	81	81	82	83	84	84	86	87	87	87	88	89	89	89	89	89	90	90	90	91	91	91	92	92
Comfortable (%)	19	19	18	18	18	18	17	17	16	15	14	14	13	12	12	12	11	11	11	11	11	11	10	10	10	9	9	9	8	8
Humid (%)	2	2	2	2	2	2	2	2	2	2	2	2	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0

	Dry (%)	Comfortable (%)	Humid (%)
1	79	19	2
2	79	19	2
3	80	18	2
4	80	18	2
5	80	18	2
6	80	18	2
7	81	17	2
8	81	17	2
9	82	16	2
10	83	15	2
11	84	14	2
12	84	14	2
13	86	13	1
14	87	12	1
15	87	12	1
16	87	12	1
17	88	11	1
18	89	11	0
19	89	11	0
20	89	11	0
21	89	11	0
22	89	11	0
23	90	10	0
24	90	10	0
25	90	10	0
26	91	9	0
27	91	9	0
28	91	9	0
29	92	8	0
30	92	8	0

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.

	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)	14	14	14	14	14	14	14	14	14	14	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15
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	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

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

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 30 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 126 minutes over September. Sunrise moves from 5:47 AM to 6:42 AM, and sunset from 7:20 PM to 6:05 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)	13.5	13.5	13.4	13.3	13.2	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	11.5	11.4
Sunrise (AM)	5:47	5:49	5:51	5:53	5:55	5:57	5:59	6:00	6:02	6:04	6:06	6:08	6:10	6:12	6:13	6:15	6:17	6:19	6:21	6:23	6:25	6:27	6:28	6:30	6:32	6:34	6:36	6:38	6:40	6:42
Sunset (PM)	7:20	7:17	7:15	7:12	7:10	7:07	7:04	7:02	6:59	6:57	6:54	6:52	6:49	6:46	6:44	6:41	6:38	6:36	6:33	6:31	6:28	6:25	6:23	6:20	6:18	6:15	6:12	6:10	6:07	6:05

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	13.5	5:47	7:20
2	13.5	5:49	7:17
3	13.4	5:51	7:15
4	13.3	5:53	7:12
5	13.2	5:55	7:10
6	13.2	5:57	7:07
7	13.1	5:59	7:04
8	13.0	6:00	7:02
9	13.0	6:02	6:59
10	12.9	6:04	6:57
11	12.8	6:06	6:54
12	12.7	6:08	6:52
13	12.7	6:10	6:49
14	12.6	6:12	6:46
15	12.5	6:13	6:44
16	12.4	6:15	6:41
17	12.4	6:17	6:38
18	12.3	6:19	6:36
19	12.2	6:21	6:33
20	12.1	6:23	6:31
21	12.1	6:25	6:28
22	12.0	6:27	6:25
23	11.9	6:28	6:23
24	11.8	6:30	6:20
25	11.8	6:32	6:18
26	11.7	6:34	6:15
27	11.6	6:36	6:12
28	11.5	6:38	6:10
29	11.5	6:40	6:07
30	11.4	6:42	6:05

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.65 kWh/m².

For context, solar energy here swings from a low near 0.45 kWh/m² to a high of 4.93 kWh/m² in June across the year — September's 2.65 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)	3.2	3.1	3.1	3.1	3.0	3.0	3.0	2.9	2.9	2.9	2.8	2.8	2.8	2.7	2.7	2.7	2.6	2.6	2.5	2.5	2.5	2.4	2.4	2.3	2.3	2.2	2.2	2.1	2.1	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	3.2	Moderate
2	3.1	Moderate
3	3.1	Moderate
4	3.1	Moderate
5	3.0	Moderate
6	3.0	Moderate
7	3.0	Moderate
8	2.9	Moderate
9	2.9	Moderate
10	2.9	Moderate
11	2.8	Moderate
12	2.8	Moderate
13	2.8	Moderate
14	2.7	Moderate
15	2.7	Moderate
16	2.7	Moderate
17	2.6	Moderate
18	2.6	Moderate
19	2.5	Moderate
20	2.5	Moderate
21	2.5	Moderate
22	2.4	Moderate
23	2.4	Moderate
24	2.3	Moderate
25	2.3	Moderate
26	2.2	Moderate
27	2.2	Moderate
28	2.1	Moderate
29	2.1	Moderate
30	2.1	Moderate

Planning a trip in September

Is September a good time to visit Sligo?

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

4.1

Sightseeing

4th-best month of the year

—

Beach & pool

never really warm enough

September is a reasonable time to visit Sligo for sightseeing.

What to pack for Sligo in September

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

In September, Sligo sees daytime highs around 16°C and nights near 10°C. Pack rain gear. Worth having: a warm layer. About 15 days see rain.

rain geara warm layer

Sea temperature near Sligo in September

The nearest coast averages about 15°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 15 km away) is warmest in August at about 16°C and coldest in February 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	9	11	13	15	16	15	13	12	10
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Cool	Bracing	Bracing	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	9	Bracing
Feb	8	Bracing
Mar	8	Bracing
Apr	9	Bracing
May	11	Bracing
Jun	13	Bracing
Jul	15	Bracing
Aug	16	Cool
Sep	15	Bracing
Oct	13	Bracing
Nov	12	Bracing
Dec	10	Bracing

UV index in Sligo in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sligo peaks around June 23 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 6 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	4	2	1	0
Level	Low	Low	Moderate	Moderate	Moderate	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	Moderate
Jun	5	High
Jul	5	High
Aug	5	Moderate
Sep	4	Moderate
Oct	2	Low
Nov	1	Low
Dec	0	Low

Location & terrain

Where is Sligo?

Sligo sits at 54.3°N, 8.5°W, 13 m above sea level, in Ireland. The nearest listed city is Omagh, 84 km away.

Topography around Sligo

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

Within 3 km, the terrain around Sligo has only modest variations in elevation — a maximum elevation change of 120 m around an average of 27 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 660 m; within 80 km, large variations in elevation — a maximum elevation change of 805 m.

The land around Sligo is covered by grassland (56%) and trees (21%) within 3 km, grassland (66%) within 16 km, and grassland (64%) and water (24%) within 80 km.

3 km

120 m

grassland 56%

16 km

660 m

grassland 66%

80 km

805 m

grassland 64%

treesgrasslandartificial surfaceswater

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

September weather nearby: Omagh 84 km · Letterkenny 89 km · Athlone 100 km · Londonderry County Borough 110 km · Derry 110 km · An Muileann gCearr 111 km · Galway 117 km · Tullamore 128 km

Ireland travel facts

Travel advisory: Level 1; Exercise Normal Precautions
Power plugs: Type G; 230 V · 50 Hz
Prices: ≈ 85% of US; price level, 2025
GDP per capita: $131,592; 2025
Happiness: 6.9 / 10; World Happiness, 2025
Safe drinking water: 96%; of population, 2024
Homicide rate: 0.7; per 100k, 2023
Road deaths: 3.1; 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 Sligo (54.2697°, -8.4694°, elevation 13 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	17	11
2	17	11
3	17	11
4	17	11
5	17	11
6	17	11
7	17	11
8	16	11
9	16	10
10	16	10
11	16	10
12	16	10
13	16	10
14	16	10
15	16	10
16	16	10
17	16	10
18	16	10
19	16	10
20	16	10
21	15	9
22	15	9
23	15	9
24	15	9
25	15	9
26	15	9
27	15	9
28	15	9
29	15	9
30	15	9

	Clearer (%)	Cloudier (%)
1	15	85
2	14	86
3	14	86
4	14	86
5	14	86
6	14	86
7	14	86
8	14	86
9	15	85
10	15	85
11	15	85
12	16	84
13	16	84
14	16	84
15	17	83
16	17	83
17	18	82
18	18	82
19	18	82
20	18	82
21	19	81
22	19	81
23	19	81
24	17	83
25	17	83
26	17	83
27	17	83
28	17	83
29	17	83
30	17	83

	Rain chance (%)
1	51
2	51
3	51
4	51
5	51
6	52
7	52
8	52
9	52
10	52
11	52
12	51
13	51
14	51
15	50
16	50
17	49
18	49
19	48
20	48
21	48
22	48
23	48
24	49
25	49
26	50
27	51
28	51
29	52
30	52

	Dry (%)	Comfortable (%)	Humid (%)
1	79	19	2
2	79	19	2
3	80	18	2
4	80	18	2
5	80	18	2
6	80	18	2
7	81	17	2
8	81	17	2
9	82	16	2
10	83	15	2
11	84	14	2
12	84	14	2
13	86	13	1
14	87	12	1
15	87	12	1
16	87	12	1
17	88	11	1
18	89	11	0
19	89	11	0
20	89	11	0
21	89	11	0
22	89	11	0
23	90	10	0
24	90	10	0
25	90	10	0
26	91	9	0
27	91	9	0
28	91	9	0
29	92	8	0
30	92	8	0

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

	Clearer (%)	Cloudier (%)
1	15	85
2	14	86
3	14	86
4	14	86
5	14	86
6	14	86
7	14	86
8	14	86
9	15	85
10	15	85
11	15	85
12	16	84
13	16	84
14	16	84
15	17	83
16	17	83
17	18	82
18	18	82
19	18	82
20	18	82
21	19	81
22	19	81
23	19	81
24	17	83
25	17	83
26	17	83
27	17	83
28	17	83
29	17	83
30	17	83

	Rain chance (%)
1	51
2	51
3	51
4	51
5	51
6	52
7	52
8	52
9	52
10	52
11	52
12	51
13	51
14	51
15	50
16	50
17	49
18	49
19	48
20	48
21	48
22	48
23	48
24	49
25	49
26	50
27	51
28	51
29	52
30	52

	Dry (%)	Comfortable (%)	Humid (%)
1	79	19	2
2	79	19	2
3	80	18	2
4	80	18	2
5	80	18	2
6	80	18	2
7	81	17	2
8	81	17	2
9	82	16	2
10	83	15	2
11	84	14	2
12	84	14	2
13	86	13	1
14	87	12	1
15	87	12	1
16	87	12	1
17	88	11	1
18	89	11	0
19	89	11	0
20	89	11	0
21	89	11	0
22	89	11	0
23	90	10	0
24	90	10	0
25	90	10	0
26	91	9	0
27	91	9	0
28	91	9	0
29	92	8	0
30	92	8	0

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

	Clearer (%)	Cloudier (%)
1	15	85
2	14	86
3	14	86
4	14	86
5	14	86
6	14	86
7	14	86
8	14	86
9	15	85
10	15	85
11	15	85
12	16	84
13	16	84
14	16	84
15	17	83
16	17	83
17	18	82
18	18	82
19	18	82
20	18	82
21	19	81
22	19	81
23	19	81
24	17	83
25	17	83
26	17	83
27	17	83
28	17	83
29	17	83
30	17	83

	Rain chance (%)
1	51
2	51
3	51
4	51
5	51
6	52
7	52
8	52
9	52
10	52
11	52
12	51
13	51
14	51
15	50
16	50
17	49
18	49
19	48
20	48
21	48
22	48
23	48
24	49
25	49
26	50
27	51
28	51
29	52
30	52

	Dry (%)	Comfortable (%)	Humid (%)
1	79	19	2
2	79	19	2
3	80	18	2
4	80	18	2
5	80	18	2
6	80	18	2
7	81	17	2
8	81	17	2
9	82	16	2
10	83	15	2
11	84	14	2
12	84	14	2
13	86	13	1
14	87	12	1
15	87	12	1
16	87	12	1
17	88	11	1
18	89	11	0
19	89	11	0
20	89	11	0
21	89	11	0
22	89	11	0
23	90	10	0
24	90	10	0
25	90	10	0
26	91	9	0
27	91	9	0
28	91	9	0
29	92	8	0
30	92	8	0