Castelo Branco weather in September

In September, Castelo Branco sees average daytime highs of 28°C and overnight lows near 16°C, with 34 mm of rain across 4.6 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 30°C in the first days to 26°C by the end. The sky is clear or mostly clear about 59% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Castelo Branco's 4th-clearest and 12th-windiest month. For the whole year in context, see Castelo Branco's year-round climate.

Daytime high
28°
4th warmest
Overnight low
16°
10th coldest
Rainfall
34 mm
4.6 wet days
Daylight
12 h 18 min
6:17 AM – 6:32 PM
Cloud cover
36%
4th clearest
Wind
9 km/h
12th windiest
Solar energy
5.18 kWh/m²
Travel score
7.1
out of 10

Castelo Branco is city seat of Castelo Branco 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 30°C in the first days to 26°C by the end.

A typical September day in Castelo Branco reaches about 28°C in the afternoon and slips back to 16°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 33°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

10°20°30°40°151015202530
Avg high (°C)Avg low (°C)
13117
23017
33017
43017
53017
63017
73017
82917
92916
102916
112916
122916
132816
142816
152816
162816
172815
182715
192715
202715
212715
222715
232615
242615
252615
262615
272614
282614
292514
302514

How September really feels in Castelo Branco

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
0
heat index over the day's high
Days feeling ≤ C
0
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.

Castelo Branco weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan13° / 628.29.53.7
Feb15° / 496.410.44.8
Mar18° / 587.411.76.2
Apr20° / 538.1136.6
May24° / 12°51714.27.5
Jun29° / 15°102.514.87.0
Jul32° / 18°41.314.55.1
Aug32° / 18°61.413.65.2
Sep28° / 16°344.612.37.1
Oct22° / 12°838.910.96.9
Nov16° / 778.39.85.4
Dec13° / 758.39.23.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 26%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18515
28416
38416
48317
58317
68218
78218
88020
98020
107921
117723
127723
137624
147525
157525
167327
177327
187228
197030
207030
216931
226832
236733
246733
256634
266634
276535
286535
296535
306436

Chance of precipitation in September

Any precipitation

Castelo Branco gets around 34 mm of rain over 4.6 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 15% and peaks near 20% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
17
28
38
48
59
69
710
810
911
1012
1113
1214
1314
1415
1516
1617
1717
1818
1918
2019
2119
2220
2320
2420
2520
2620
2720
2820
2920
3020

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.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
154397
254397
355387
455387
556377
657367
758357
859347
959347
1060337
1160337
1260328
1361318
1461318
1562308
1661309
1762299
1862299
1963289
2064288
2164288
2265278
2365278
2465278
2565278
2666268
2767267
2867267
2968257
3068257

Wind in September

Winds average 9 km/h in September, the calmest month.

Across September, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min 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 78 minutes over September. Sunrise moves from 6:02 AM to 6:30 AM, and sunset from 6:57 PM to 6:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.96:026:57
212.96:036:56
312.86:046:54
412.86:056:52
512.76:066:51
612.76:076:49
712.76:086:47
812.66:096:46
912.66:106:44
1012.56:116:42
1112.56:126:41
1212.46:136:39
1312.46:146:37
1412.36:156:35
1512.36:166:34
1612.36:176:32
1712.26:186:30
1812.26:186:29
1912.16:196:27
2012.16:206:25
2112.06:216:23
2212.06:226:22
2311.96:236:20
2411.96:246:18
2511.96:256:17
2611.86:266:15
2711.86:276:13
2811.76:286:12
2911.76:296:10
3011.66:306:08

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.18 kWh/m².

For context, solar energy here swings from a low near 1.83 kWh/m² to a high of 7.74 kWh/m² in July across the year — September's 5.18 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.0Intense
36.0Bright
45.9Bright
55.8Bright
65.8Bright
75.7Bright
85.7Bright
95.6Bright
105.5Bright
115.5Bright
125.4Bright
135.3Bright
145.3Bright
155.2Bright
165.1Bright
175.1Bright
185.0Bright
194.9Bright
204.9Bright
214.8Bright
224.8Bright
234.7Bright
244.7Bright
254.6Bright
264.5Bright
274.5Bright
284.5Bright
294.4Bright
304.4Bright
Planning a trip in September

Is September a good time to visit Castelo Branco?

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

7.1
Sightseeing
2nd-best month of the year
7.9
Beach & pool
4th-best month of the year

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

What to pack for Castelo Branco in September

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

In September, Castelo Branco sees daytime highs around 28°C and nights near 16°C. Pack light clothes. Worth having: sun protection. About 5 days see rain.

light clothessun protection

UV index in Castelo Branco in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Castelo Branco peaks around July 17 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 17UV 9Dec 18UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar6High
Apr7High
May7High
Jun9Very high
Jul9Very high
Aug9Very high
Sep6High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Castelo Branco 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 Castelo Branco is worst in August — around 21 µg/m³ PM2.5 (moderate), about 3.3× the cleanest month (November, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateModerateGoodAug 1620 µg/m³Nov 236 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb10Good
Mar12Moderate
Apr10Good
May8Good
Jun9Good
Jul12Good
Aug21Moderate
Sep10Good
Oct14Moderate
Nov6Good
Dec7Good
Location & terrain

Where is Castelo Branco?

Castelo Branco sits at 39.8°N, 7.5°W, 371 m above sea level, in Portugal. The nearest listed city is Covilhã, 51 km away.

Topography around Castelo Branco

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

Within 3 km, the terrain around Castelo Branco has only modest variations in elevation — a maximum elevation change of 184 m around an average of 362 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 363 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,974 m.

The land around Castelo Branco is covered by grassland (48%), trees (27%) and artificial surfaces (21%) within 3 km, grassland (49%) and trees (39%) within 16 km, and grassland (50%) and trees (43%) within 80 km.

3 km
184 m
16 km
363 m
80 km
1,974 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Covilhã 51 km · Portalegre 59 km · Guarda 82 km · Tomar 82 km · Sequeira 84 km · Santo António dos Olivais 89 km · Coimbra 90 km · São Paulo de Frades 90 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 Castelo Branco (39.8236°, -7.491°, elevation 371 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. 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).