Southsea weather in September

In September, Southsea sees average daytime highs of 18°C and overnight lows near 14°C, with 62 mm of rain across 10.2 wet days and about 12.4 hours of daylight. It is the 3rd-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 16°C by the end. The sky is clear or mostly clear about 21% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 24 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Southsea's 4th-clearest and 7th-windiest month. For the whole year in context, see Southsea's year-round climate.

Daytime high: 18°; 3rd warmest
Overnight low: 14°; 10th coldest
Rainfall: 62 mm; 10.2 wet days
Daylight: 12 h 24 min; 5:47 AM – 6:10 PM
Cloud cover: 64%; 4th clearest
Wind: 19 km/h; 7th windiest
Solar energy: 3.28 kWh/m²
Travel score: 5.6; out of 10

Southsea is town in Hampshire, England.

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

← August Southsea 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 19°C in the first days to 16°C by the end.

A typical September day in Southsea reaches about 18°C in the afternoon and slips back to 14°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 20°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)	19	19	19	19	18	18	18	18	18	18	18	18	18	18	18	18	18	17	17	17	17	17	17	17	17	17	17	17	16	16
Avg low (°C)	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	13	13	13	13	13	13	13	13	13	13	13	13	13	13

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

Southsea weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 6th-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°	84	13.4	0.6	8.2	1.3
Feb	8° / 5°	60	10.5	0.5	9.7	1.2
Mar	9° / 6°	50	10.1	0.3	11.5	1.9
Apr	11° / 7°	52	9.7	0.1	13.5	2.9
May	14° / 10°	50	9.1	0	15.2	4.2
Jun	17° / 13°	51	9.5	0	16.2	5.4
Jul	19° / 15°	52	9.6	0	15.8	6.2
Aug	19° / 15°	64	9.9	0	14.3	6.1
Sep	18° / 14°	62	10.2	0	12.4	5.6
Oct	15° / 11°	96	13.4	0	10.4	4.0
Nov	11° / 8°	99	13.8	0	8.7	2.5
Dec	9° / 6°	92	13.4	0.3	7.8	1.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 61%.

	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 (%)	42	42	41	41	41	42	42	41	41	41	40	40	40	39	39	39	39	39	39	39	39	39	38	38	37	37	37	37	37	36
Cloudier (%)	58	58	59	59	59	58	58	59	59	59	60	60	60	61	61	61	61	61	61	61	61	61	62	62	63	63	63	63	63	64

	Clearer (%)	Cloudier (%)
1	42	58
2	42	58
3	41	59
4	41	59
5	41	59
6	42	58
7	42	58
8	41	59
9	41	59
10	41	59
11	40	60
12	40	60
13	40	60
14	39	61
15	39	61
16	39	61
17	39	61
18	39	61
19	39	61
20	39	61
21	39	61
22	39	61
23	38	62
24	38	62
25	37	63
26	37	63
27	37	63
28	37	63
29	37	63
30	36	64

Chance of precipitation in September

Any precipitation

Southsea gets around 62 mm of rain over 10.2 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 34% and peaks near 44% on the wettest days. The odds climb toward the end of the month.

	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 (%)	29	29	29	28	29	29	29	30	30	31	31	31	31	32	32	33	33	34	35	36	36	37	38	39	40	41	42	42	43	44

	Rain chance (%)
1	29
2	29
3	29
4	28
5	29
6	29
7	29
8	30
9	30
10	31
11	31
12	31
13	31
14	32
15	32
16	33
17	33
18	34
19	35
20	36
21	36
22	37
23	38
24	39
25	40
26	41
27	42
28	42
29	43
30	44

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 61% 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 (%)	49	51	52	53	54	55	56	57	58	59	60	61	62	63	63	64	65	64	65	64	65	65	64	65	65	66	66	67	69	70
Comfortable (%)	41	40	39	38	37	36	35	34	33	32	31	31	30	30	30	30	30	31	31	32	32	32	33	33	33	32	32	31	30	29
Humid (%)	10	9	9	9	9	9	9	9	9	9	9	8	8	7	7	6	5	5	4	4	3	3	3	2	2	2	2	2	1	1

	Dry (%)	Comfortable (%)	Humid (%)
1	49	41	10
2	51	40	9
3	52	39	9
4	53	38	9
5	54	37	9
6	55	36	9
7	56	35	9
8	57	34	9
9	58	33	9
10	59	32	9
11	60	31	9
12	61	31	8
13	62	30	8
14	63	30	7
15	63	30	7
16	64	30	6
17	65	30	5
18	64	31	5
19	65	31	4
20	64	32	4
21	65	32	3
22	65	32	3
23	64	33	3
24	65	33	2
25	65	33	2
26	66	32	2
27	66	32	2
28	67	31	2
29	69	30	1
30	70	29	1

Wind in September

Winds average 19 km/h in September.

Across September, daily wind ranges from about 19 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)	19	19	19	19	19	19	19	19	19	19	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	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	light breeze	light breeze	light breeze	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy

	Wind speed (km/h)	Feels
1	19	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	19	light breeze
10	19	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	light breeze
20	20	light breeze
21	20	light breeze
22	20	breezy
23	20	breezy
24	20	breezy
25	20	breezy
26	20	breezy
27	20	breezy
28	20	breezy
29	21	breezy
30	21	breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 24 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 114 minutes over September. Sunrise moves from 5:23 AM to 6:10 AM, and sunset from 6:45 PM to 5:37 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)	13.4	13.3	13.2	13.2	13.1	13.0	13.0	12.9	12.8	12.8	12.7	12.6	12.6	12.5	12.4	12.4	12.3	12.2	12.2	12.1	12.0	12.0	11.9	11.9	11.8	11.7	11.7	11.6	11.5	11.5
Sunrise (AM)	5:23	5:25	5:27	5:28	5:30	5:31	5:33	5:35	5:36	5:38	5:39	5:41	5:43	5:44	5:46	5:47	5:49	5:51	5:52	5:54	5:55	5:57	5:59	6:00	6:02	6:03	6:05	6:07	6:08	6:10
Sunset (PM)	6:45	6:42	6:40	6:38	6:36	6:33	6:31	6:29	6:26	6:24	6:22	6:19	6:17	6:15	6:12	6:10	6:08	6:05	6:03	6:01	5:58	5:56	5:54	5:51	5:49	5:47	5:44	5:42	5:40	5:37

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	13.4	5:23	6:45
2	13.3	5:25	6:42
3	13.2	5:27	6:40
4	13.2	5:28	6:38
5	13.1	5:30	6:36
6	13.0	5:31	6:33
7	13.0	5:33	6:31
8	12.9	5:35	6:29
9	12.8	5:36	6:26
10	12.8	5:38	6:24
11	12.7	5:39	6:22
12	12.6	5:41	6:19
13	12.6	5:43	6:17
14	12.5	5:44	6:15
15	12.4	5:46	6:12
16	12.4	5:47	6:10
17	12.3	5:49	6:08
18	12.2	5:51	6:05
19	12.2	5:52	6:03
20	12.1	5:54	6:01
21	12.0	5:55	5:58
22	12.0	5:57	5:56
23	11.9	5:59	5:54
24	11.9	6:00	5:51
25	11.8	6:02	5:49
26	11.7	6:03	5:47
27	11.7	6:05	5:44
28	11.6	6:07	5:42
29	11.5	6:08	5:40
30	11.5	6:10	5:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.28 kWh/m².

For context, solar energy here swings from a low near 0.71 kWh/m² to a high of 5.67 kWh/m² in June across the year — September's 3.28 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)	3.9	3.9	3.9	3.8	3.8	3.7	3.7	3.6	3.6	3.5	3.5	3.4	3.4	3.4	3.3	3.3	3.2	3.1	3.1	3.1	3.0	3.0	2.9	2.9	2.8	2.8	2.7	2.7	2.6	2.6
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	3.9	Moderate
2	3.9	Moderate
3	3.9	Moderate
4	3.8	Moderate
5	3.8	Moderate
6	3.7	Moderate
7	3.7	Moderate
8	3.6	Moderate
9	3.6	Moderate
10	3.5	Moderate
11	3.5	Moderate
12	3.4	Moderate
13	3.4	Moderate
14	3.4	Moderate
15	3.3	Moderate
16	3.3	Moderate
17	3.2	Moderate
18	3.1	Moderate
19	3.1	Moderate
20	3.1	Moderate
21	3.0	Moderate
22	3.0	Moderate
23	2.9	Moderate
24	2.9	Moderate
25	2.8	Moderate
26	2.8	Moderate
27	2.7	Moderate
28	2.7	Moderate
29	2.6	Moderate
30	2.6	Moderate

Planning a trip in September

Is September a good time to visit Southsea?

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

5.6

Sightseeing

3rd-best month of the year

1.7

Beach & pool

3rd-best month of the year

September is a reasonable time to visit Southsea for sightseeing.

What to pack for Southsea in September

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

In September, Southsea sees daytime highs around 18°C and nights near 14°C. Worth packing: rain gear. About 10 days see rain.

rain gear

Sea temperature near Southsea in September

The nearest coast averages about 17°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 August at about 18°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	9	11	14	16	18	17	16	13	11
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Cool	Cool	Cool	Cool	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	9	Bracing
Feb	8	Bracing
Mar	8	Bracing
Apr	9	Bracing
May	11	Bracing
Jun	14	Bracing
Jul	16	Cool
Aug	18	Cool
Sep	17	Cool
Oct	16	Cool
Nov	13	Bracing
Dec	11	Bracing

UV index in Southsea 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 Southsea peaks around August 11 at about 6 (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 6 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	1	1	3	4	6	6	6	6	4	2	1	1
Level	Low	Low	Moderate	Moderate	High	High	High	High	Moderate	Moderate	Low	Low

	UV index (midday)	Level
Jan	1	Low
Feb	1	Low
Mar	3	Moderate
Apr	4	Moderate
May	6	High
Jun	6	High
Jul	6	High
Aug	6	High
Sep	4	Moderate
Oct	2	Moderate
Nov	1	Low
Dec	1	Low

Location & terrain

Where is Southsea?

Southsea sits at 50.8°N, 1.1°W, 3 m above sea level, in United Kingdom. The nearest listed city is Portsmouth, 2.0 km away.

Topography around Southsea

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

Within 3 km, the terrain around Southsea has only modest variations in elevation — a maximum elevation change of 18 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 135 m; within 80 km, significant variations in elevation — a maximum elevation change of 302 m.

The land around Southsea is covered by water (54%) and artificial surfaces (35%) within 3 km, water (46%) within 16 km, and water (35%), grassland (24%) and trees (20%) within 80 km.

3 km

18 m

water 54%

16 km

135 m

water 46%

80 km

302 m

water 35%

treesgrasslandcroplandartificial surfacesbare terrainwaterwetland

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

September weather nearby: Portsmouth 2.0 km · Gosport 3.0 km · Ryde 8.0 km · South Hayling 8.0 km · Hayling Island 9.0 km · Fareham 10 km · Havant 11 km · Waterlooville 12 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 Southsea (50.7835°, -1.0907°, elevation 3 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	19	14
2	19	14
3	19	14
4	19	14
5	18	14
6	18	14
7	18	14
8	18	14
9	18	14
10	18	14
11	18	14
12	18	14
13	18	14
14	18	14
15	18	14
16	18	14
17	18	13
18	17	13
19	17	13
20	17	13
21	17	13
22	17	13
23	17	13
24	17	13
25	17	13
26	17	13
27	17	13
28	17	13
29	16	13
30	16	13

	Clearer (%)	Cloudier (%)
1	42	58
2	42	58
3	41	59
4	41	59
5	41	59
6	42	58
7	42	58
8	41	59
9	41	59
10	41	59
11	40	60
12	40	60
13	40	60
14	39	61
15	39	61
16	39	61
17	39	61
18	39	61
19	39	61
20	39	61
21	39	61
22	39	61
23	38	62
24	38	62
25	37	63
26	37	63
27	37	63
28	37	63
29	37	63
30	36	64

	Rain chance (%)
1	29
2	29
3	29
4	28
5	29
6	29
7	29
8	30
9	30
10	31
11	31
12	31
13	31
14	32
15	32
16	33
17	33
18	34
19	35
20	36
21	36
22	37
23	38
24	39
25	40
26	41
27	42
28	42
29	43
30	44

	Dry (%)	Comfortable (%)	Humid (%)
1	49	41	10
2	51	40	9
3	52	39	9
4	53	38	9
5	54	37	9
6	55	36	9
7	56	35	9
8	57	34	9
9	58	33	9
10	59	32	9
11	60	31	9
12	61	31	8
13	62	30	8
14	63	30	7
15	63	30	7
16	64	30	6
17	65	30	5
18	64	31	5
19	65	31	4
20	64	32	4
21	65	32	3
22	65	32	3
23	64	33	3
24	65	33	2
25	65	33	2
26	66	32	2
27	66	32	2
28	67	31	2
29	69	30	1
30	70	29	1

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

	Clearer (%)	Cloudier (%)
1	42	58
2	42	58
3	41	59
4	41	59
5	41	59
6	42	58
7	42	58
8	41	59
9	41	59
10	41	59
11	40	60
12	40	60
13	40	60
14	39	61
15	39	61
16	39	61
17	39	61
18	39	61
19	39	61
20	39	61
21	39	61
22	39	61
23	38	62
24	38	62
25	37	63
26	37	63
27	37	63
28	37	63
29	37	63
30	36	64

	Rain chance (%)
1	29
2	29
3	29
4	28
5	29
6	29
7	29
8	30
9	30
10	31
11	31
12	31
13	31
14	32
15	32
16	33
17	33
18	34
19	35
20	36
21	36
22	37
23	38
24	39
25	40
26	41
27	42
28	42
29	43
30	44

	Dry (%)	Comfortable (%)	Humid (%)
1	49	41	10
2	51	40	9
3	52	39	9
4	53	38	9
5	54	37	9
6	55	36	9
7	56	35	9
8	57	34	9
9	58	33	9
10	59	32	9
11	60	31	9
12	61	31	8
13	62	30	8
14	63	30	7
15	63	30	7
16	64	30	6
17	65	30	5
18	64	31	5
19	65	31	4
20	64	32	4
21	65	32	3
22	65	32	3
23	64	33	3
24	65	33	2
25	65	33	2
26	66	32	2
27	66	32	2
28	67	31	2
29	69	30	1
30	70	29	1

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

	Clearer (%)	Cloudier (%)
1	42	58
2	42	58
3	41	59
4	41	59
5	41	59
6	42	58
7	42	58
8	41	59
9	41	59
10	41	59
11	40	60
12	40	60
13	40	60
14	39	61
15	39	61
16	39	61
17	39	61
18	39	61
19	39	61
20	39	61
21	39	61
22	39	61
23	38	62
24	38	62
25	37	63
26	37	63
27	37	63
28	37	63
29	37	63
30	36	64

	Rain chance (%)
1	29
2	29
3	29
4	28
5	29
6	29
7	29
8	30
9	30
10	31
11	31
12	31
13	31
14	32
15	32
16	33
17	33
18	34
19	35
20	36
21	36
22	37
23	38
24	39
25	40
26	41
27	42
28	42
29	43
30	44

	Dry (%)	Comfortable (%)	Humid (%)
1	49	41	10
2	51	40	9
3	52	39	9
4	53	38	9
5	54	37	9
6	55	36	9
7	56	35	9
8	57	34	9
9	58	33	9
10	59	32	9
11	60	31	9
12	61	31	8
13	62	30	8
14	63	30	7
15	63	30	7
16	64	30	6
17	65	30	5
18	64	31	5
19	65	31	4
20	64	32	4
21	65	32	3
22	65	32	3
23	64	33	3
24	65	33	2
25	65	33	2
26	66	32	2
27	66	32	2
28	67	31	2
29	69	30	1
30	70	29	1