Leça do Bailio weather in September

In September, Leça do Bailio sees average daytime highs of 22°C and overnight lows near 17°C, with 54 mm of rain across 6.3 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 22°C in the first days to 21°C by the end. The sky is clear or mostly clear about 54% of the time in September, and the air most often feels humid.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Leça do Bailio's 3rd-clearest and 12th-windiest month. For the whole year in context, see Leça do Bailio's year-round climate.

Daytime high
22°
3rd warmest
Overnight low
17°
10th coldest
Rainfall
54 mm
6.3 wet days
Daylight
12 h 18 min
6:21 AM – 6:37 PM
Cloud cover
40%
3rd clearest
Wind
14 km/h
12th windiest
Solar energy
4.95 kWh/m²
Travel score
7.4
out of 10

Leça do Bailio is human settlement in Portugal.

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 22°C in the first days to 21°C by the end.

A typical September day in Leça do Bailio reaches about 22°C in the afternoon and slips back to 17°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 25°C. Set against its neighbours, September runs about 1°C cooler than August and about 3°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12318
22218
32218
42218
52218
62218
72218
82217
92217
102217
112217
122217
132217
142217
152217
162217
172117
182117
192117
202117
212117
222117
232117
242116
252116
262116
272116
282116
292116
302016

Leça do Bailio 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
Jan13° / 13312.39.43.5
Feb14° / 919.310.33.9
Mar15° / 11°10610.211.74.7
Apr16° / 12°10711.213.15.1
May18° / 14°9010.414.36.1
Jun21° / 16°315.514.97.4
Jul22° / 18°183.414.78.4
Aug23° / 18°223.813.68.4
Sep22° / 17°546.312.37.4
Oct19° / 15°14812.510.95.9
Nov16° / 12°15613.39.74.6
Dec14° / 10°15112.89.13.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 30%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17822
27822
37822
47723
57723
67624
77624
87525
97525
107426
117327
127228
137129
147129
157030
166931
176931
186832
196733
206634
216634
226535
236436
246337
256337
266238
276238
286139
296139
306040

Chance of precipitation in September

Any precipitation

Leça do Bailio gets around 54 mm of rain over 6.3 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 22% and peaks near 28% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
115
215
315
416
516
616
717
817
918
1018
1119
1220
1320
1421
1522
1622
1723
1823
1924
2024
2125
2225
2325
2426
2526
2627
2727
2827
2928
3028

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 49% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1528598
2528598
3528598
4628588
5629578
6629578
7730558
8730567
9731557
10831547
11832537
12833527
13934516
14935506
15936505
161037495
171038484
181039474
191140463
201141453
211141453
221242442
231242432
241243432
251343422
261443412
271444402
281544392
291644382
301844362

Wind in September

Winds average 14 km/h in September, the calmest month.

Across September, daily wind ranges from about 14 km/h on the calmest days to 14 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
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

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

Days shrink by about 84 minutes over September. Sunrise moves from 6:05 AM to 6:35 AM, and sunset from 7:03 PM to 6:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.06:057:03
212.96:067:02
312.96:077:00
412.86:086:58
512.86:096:56
612.76:106:55
712.76:116:53
812.66:126:51
912.66:146:49
1012.66:156:48
1112.56:166:46
1212.56:176:44
1312.46:186:42
1412.46:196:41
1512.36:206:39
1612.36:216:37
1712.26:226:35
1812.26:236:33
1912.16:246:32
2012.16:256:30
2112.06:266:28
2212.06:276:26
2311.96:286:25
2411.96:296:23
2511.86:306:21
2611.86:316:19
2711.86:326:17
2811.76:336:16
2911.76:346:14
3011.66:356:12

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.95 kWh/m².

For context, solar energy here swings from a low near 1.68 kWh/m² to a high of 7.33 kWh/m² in July across the year — September's 4.95 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.8Bright
25.7Bright
35.7Bright
45.6Bright
55.6Bright
65.5Bright
75.4Bright
85.4Bright
95.3Bright
105.3Bright
115.2Bright
125.1Bright
135.1Bright
145.0Bright
155.0Bright
164.9Bright
174.8Bright
184.8Bright
194.7Bright
204.7Bright
214.6Bright
224.6Bright
234.5Bright
244.5Bright
254.4Bright
264.3Bright
274.3Bright
284.3Bright
294.2Bright
304.2Bright
Planning a trip in September

Hazard calendar for Leça do Bailio

In seasonPeak

None of Leça do Bailio's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Leça do Bailio's rainy season runs October–May, when most of the year's rain falls.

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

Is September a good time to visit Leça do Bailio?

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

7.4
Sightseeing
3rd-best month of the year
4.9
Beach & pool
3rd-best month of the year

September is one of the better times to visit Leça do Bailio for general sightseeing.

What to pack for Leça do Bailio in September

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

In September, Leça do Bailio sees daytime highs around 22°C and nights near 17°C. Worth packing: sun protection. About 6 days see rain.

sun protection

Sea temperature near Leça do Bailio 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 offshore is warmest in September at about 17°C and coldest in February near 13°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

12°14°16°18°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar14Bracing
Apr14Bracing
May16Cool
Jun17Cool
Jul17Cool
Aug17Cool
Sep17Cool
Oct17Cool
Nov16Cool
Dec14Bracing

UV index in Leça do Bailio in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Leça do Bailio peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 23UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7High
Jun9Very high
Jul9Very high
Aug8Very high
Sep5High
Oct4Moderate
Nov2Moderate
Dec2Low

Air quality in Leça do Bailio in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Leça do Bailio is worst in September — around 19 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (November, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodSep 1318 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar12Moderate
Apr11Good
May9Good
Jun9Good
Jul8Good
Aug16Moderate
Sep19Moderate
Oct13Moderate
Nov7Good
Dec7Good
Location & terrain

Where is Leça do Bailio?

Leça do Bailio sits at 41.2°N, 8.6°W, 90 m above sea level, in Portugal. The nearest listed city is São Tiago de Custoias, 1.0 km away.

Topography around Leça do Bailio

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

Within 3 km, the terrain around Leça do Bailio has only modest variations in elevation — a maximum elevation change of 105 m around an average of 69 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 377 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,466 m.

The land around Leça do Bailio is covered by artificial surfaces (50%) and trees (26%) within 3 km, trees (29%), water (28%) and artificial surfaces (24%) within 16 km, and trees (41%), water (27%) and grassland (24%) within 80 km.

3 km
105 m
16 km
377 m
80 km
1,466 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: São Tiago de Custoias 1.0 km · Maia 3.0 km · São Mamede de Infesta 3.0 km · Senhora da Hora 3.0 km · Vermoim 4.0 km · Águas Santas 5.0 km · Paranhos 5.0 km · Matosinhos 6.0 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 Leça do Bailio (41.212°, -8.6342°, elevation 90 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).