Olhão weather in September

In September, Olhão sees average daytime highs of 23°C and overnight lows near 20°C, with 17 mm of rain across 2.7 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 24°C in the first days to 22°C by the end. The sky is clear or mostly clear about 70% of the time in September, and the air most often feels humid.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Olhão's 4th-clearest and 12th-windiest month. For the whole year in context, see Olhão's year-round climate.

Daytime high
23°
3rd warmest
Overnight low
20°
10th coldest
Rainfall
17 mm
2.7 wet days
Daylight
12 h 12 min
6:19 AM – 6:33 PM
Cloud cover
28%
4th clearest
Wind
15 km/h
12th windiest
Solar energy
5.64 kWh/m²
Travel score
8.6
out of 10

Olhão is city seat of Olhão municipality.

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 24°C in the first days to 22°C by the end.

A typical September day in Olhão reaches about 23°C in the afternoon and slips back to 20°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 25°C. Set against its neighbours, September runs about 2°C cooler than August and about 2°C warmer than October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12421
22421
32421
42421
52420
62420
72420
82420
92420
102420
112320
122320
132320
142320
152320
162320
172320
182320
192320
202319
212319
222219
232219
242219
252219
262219
272219
282219
292219
302219

Olhão weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan15° / 12°536.99.75.0
Feb15° / 12°455.410.65.2
Mar16° / 13°516.211.75.8
Apr17° / 14°405.512.96.5
May20° / 16°244.4147.5
Jun22° / 19°50.814.58.9
Jul25° / 20°10.114.39.6
Aug25° / 21°20.313.49.5
Sep23° / 20°172.712.38.6
Oct21° / 18°676.5117.2
Nov18° / 15°687.2106.4
Dec16° / 13°867.69.55.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 70% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 17%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1928
2928
3928
4919
59010
69010
78911
88812
98812
108614
118614
128515
138515
148416
158317
168317
178218
188218
198020
208020
218020
227921
237921
247822
257723
267723
277624
287624
297624
307426

Chance of precipitation in September

Any precipitation

Olhão gets around 17 mm of rain over 2.7 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 9% and peaks near 13% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
12
22
32
42
53
63
74
84
95
106
116
127
138
149
159
1610
1710
1811
1911
2012
2112
2213
2313
2413
2513
2613
2713
2813
2913
3013

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the humid band about 50% of days. Sticky, muggy-or-worse air turns up on roughly 20% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
12175625
22175625
32185525
43185425
53185425
64195324
74195324
85205124
95215123
106215023
116225022
126234922
137234921
147244821
157244820
168254720
178254720
188264719
198264719
208264718
218274818
228274817
238274817
248274916
258274916
269274915
279284915
2810284814
2910284814
3011284813

Wind in September

Winds average 15 km/h in September, the calmest month.

Across September, daily wind ranges from about 15 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 6:06 AM to 6:31 AM, and sunset from 6:56 PM to 6:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:066:56
212.86:076:55
312.86:086:53
412.76:096:51
512.76:096:50
612.66:106:48
712.66:116:47
812.66:126:45
912.56:136:44
1012.56:146:42
1112.46:146:41
1212.46:156:39
1312.46:166:37
1412.36:176:36
1512.36:186:34
1612.26:196:33
1712.26:206:31
1812.26:206:30
1912.16:216:28
2012.16:226:26
2112.06:236:25
2212.06:246:23
2311.96:256:22
2411.96:256:20
2511.96:266:18
2611.86:276:17
2711.86:286:15
2811.76:296:14
2911.76:306:12
3011.76:316:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.64 kWh/m².

For context, solar energy here swings from a low near 2.34 kWh/m² to a high of 7.93 kWh/m² in July across the year — September's 5.64 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.5Intense
26.4Intense
36.3Intense
46.3Intense
56.2Intense
66.2Intense
76.1Intense
86.1Intense
96.0Intense
106.0Bright
115.9Bright
125.8Bright
135.8Bright
145.7Bright
155.7Bright
165.6Bright
175.6Bright
185.5Bright
195.4Bright
205.4Bright
215.3Bright
225.3Bright
235.2Bright
245.2Bright
255.1Bright
265.1Bright
275.0Bright
285.0Bright
294.9Bright
304.9Bright
Planning a trip in September

Is September a good time to visit Olhão?

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

8.6
Sightseeing
4th-best month of the year
6.7
Beach & pool
3rd-best month of the year

September is one of the better times to visit Olhão for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Olhão in September

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

In September, Olhão sees daytime highs around 23°C and nights near 20°C. Worth packing: light clothes and sun protection.

light clothessun protection

Sea temperature near Olhão in September

The nearest coast averages about 21°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 17 km away) is warmest in August at about 22°C and coldest in February near 16°C.

It's comfortable for a long swim from Jun 22 to Oct 25 — about 4.1 months when the water holds above 20°C.

14°16°18°20°22°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°C)Comfort
Jan17Cool
Feb16Cool
Mar16Cool
Apr17Cool
May18Cool
Jun20Cool
Jul21Refreshing
Aug22Refreshing
Sep21Refreshing
Oct21Refreshing
Nov19Cool
Dec17Cool

UV index in Olhão in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Olhão peaks around July 14 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateVery highHighModerateJul 14UV 10Dec 19UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar7High
Apr8Very high
May7Very high
Jun9Very high
Jul10Extreme
Aug9Very high
Sep7High
Oct5High
Nov3Moderate
Dec2Low
Location & terrain

Where is Olhão?

Olhão sits at 37.0°N, 7.8°W, 11 m above sea level, in Portugal. The nearest listed city is Quelfes, 4.0 km away.

Topography around Olhão

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

Within 3 km, the terrain around Olhão has only modest variations in elevation — a maximum elevation change of 66 m around an average of 11 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 408 m; within 80 km, large variations in elevation — a maximum elevation change of 894 m.

The land around Olhão is covered by water (36%) and grassland (28%) within 3 km, water (47%) and grassland (24%) within 16 km, and water (41%) and grassland (30%) within 80 km.

3 km
66 m
16 km
408 m
80 km
894 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Quelfes 4.0 km · Laranjeiro 5.0 km · Faro 8.0 km · Loulé 20 km · Tavira 20 km · Quarteira 23 km · Albufeira 37 km · Ayamonte 44 km

Portugal travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E / F
230 V · 50 Hz
Prices
≈ 60% of US
price level, 2025
GDP per capita
$32,082
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
95%
of population, 2024
Homicide rate
0.7
per 100k, 2022
Road deaths
8.2
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 612
Religion
Catholic 68%not applicable 13%no religion 12%no response 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 Olhão (37.0286°, -7.8411°, elevation 11 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).