Castro Alves weather in September

In September, Castro Alves sees average daytime highs of 28°C and overnight lows near 19°C, with 26 mm of rain across 10.5 wet days and about 11.9 hours of daylight. It is the 9th-warmest and 12th-wettest month of the year here.

Highs climb over the month, from about 27°C in the first days to 29°C by the end. The sky is clear or mostly clear about 19% of the time in September, and the air most often feels muggy.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Castro Alves's 2nd-clearest and 3rd-windiest month. For the whole year in context, see Castro Alves's year-round climate.

Daytime high
28°
9th warmest
Overnight low
19°
3rd coldest
Rainfall
26 mm
10.5 wet days
Daylight
11 h 54 min
5:34 AM – 5:30 PM
Cloud cover
55%
2nd clearest
Wind
11 km/h
3rd windiest
Solar energy
4.81 kWh/m²
Travel score
5.9
out of 10

Castro Alves is human settlement in Brazil.

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 27°C in the first days to 29°C by the end.

A typical September day in Castro Alves reaches about 28°C in the afternoon and slips back to 19°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 31°C. Set against its neighbours, September runs about 2°C warmer than August and about 2°C cooler than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12719
22719
32819
42819
52819
62819
72819
82819
92819
102819
112819
122819
132819
142819
152819
162819
172819
182819
192919
202919
212920
222920
232920
242920
252920
262920
272920
282920
292920
302920

How September really feels in Castro Alves

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.

Castro Alves weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 22°6912.212.74.1
Feb32° / 22°4711.512.44.0
Mar31° / 22°6013.912.13.9
Apr30° / 22°4914.911.74.4
May28° / 21°351211.45.5
Jun27° / 20°3412.911.36.1
Jul26° / 19°3613.211.36.2
Aug27° / 19°3313.711.66.0
Sep28° / 19°2610.511.95.9
Oct30° / 20°3410.612.35.1
Nov31° / 21°5611.112.64.5
Dec31° / 22°569.412.74.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 44% of September, with mostly cloudy or overcast conditions the remaining 37%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16139
26238
36238
46139
56139
66139
76139
86139
96238
106238
116238
126337
136337
146337
156436
166436
176436
186535
196535
206436
216535
226535
236535
246535
256535
266535
276535
286634
296634
306634

Chance of precipitation in September

Any precipitation

Castro Alves gets around 26 mm of rain over 10.5 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 36% and peaks near 41% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
141
240
340
440
540
640
739
839
938
1038
1138
1237
1337
1437
1536
1636
1736
1835
1934
2034
2133
2233
2332
2432
2532
2632
2732
2833
2933
3033

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 73% of days. Sticky, muggy-or-worse air turns up on roughly 74% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1333640
2333640
3332650
4332650
5331660
6331660
7330670
8330670
9329680
10329680
11228700
12227710
13226720
14225730
15224740
16223750
17122770
18122761
19121771
20120781
21119791
22119791
23118792
24117802
25117793
26116803
27115804
28015814
29015805
30014806

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 5:45 AM to 5:24 AM, and sunset from 5:30 PM to 5:30 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.85:455:30
211.85:445:30
311.85:445:30
411.85:435:30
511.85:425:30
611.85:415:30
711.85:415:30
811.85:405:30
911.85:395:30
1011.95:395:30
1111.95:385:30
1211.95:375:30
1311.95:365:30
1411.95:365:30
1511.95:355:30
1611.95:345:30
1711.95:335:30
1812.05:335:30
1912.05:325:30
2012.05:315:30
2112.05:305:30
2212.05:305:30
2312.05:295:30
2412.05:285:30
2512.05:285:30
2612.15:275:30
2712.15:265:30
2812.15:255:30
2912.15:255:30
3012.15:245:30

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.81 kWh/m².

For context, solar energy here swings from a low near 3.41 kWh/m² to a high of 5.87 kWh/m² in January across the year — September's 4.81 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.6Bright
74.6Bright
84.6Bright
94.6Bright
104.7Bright
114.7Bright
124.7Bright
134.7Bright
144.8Bright
154.8Bright
164.8Bright
174.9Bright
184.9Bright
194.9Bright
205.0Bright
215.0Bright
225.0Bright
235.0Bright
245.1Bright
255.1Bright
265.1Bright
275.2Bright
285.2Bright
295.2Bright
305.2Bright
Planning a trip in September

Is September a good time to visit Castro Alves?

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

5.9
Sightseeing
4th-best month of the year
6.7
Beach & pool
2nd-best month of the year

September is a reasonable time to visit Castro Alves for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Castro Alves in September

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

In September, Castro Alves sees daytime highs around 28°C and nights near 19°C. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

UV index in Castro Alves in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Castro Alves peaks around February 17 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 23 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeFeb 17UV 15Jun 23UV 9
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar14Extreme
Apr12Extreme
May9Very high
Jun9Very high
Jul9Very high
Aug10Extreme
Sep11Extreme
Oct13Extreme
Nov13Extreme
Dec12Extreme
Location & terrain

Where is Castro Alves?

Castro Alves sits at 12.8°S, 39.4°W, 255 m above sea level, in Brazil. The nearest listed city is Sapeaçu, 27 km away.

Topography around Castro Alves

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

Within 3 km, the terrain around Castro Alves has only modest variations in elevation — a maximum elevation change of 134 m around an average of 248 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 689 m; within 80 km, large variations in elevation — a maximum elevation change of 931 m.

The land around Castro Alves is covered by grassland (87%) within 3 km, grassland (78%) within 16 km, and grassland (60%) and trees (30%) within 80 km.

3 km
134 m
16 km
689 m
80 km
931 m
treesshrubsgrasslandcroplandartificial surfaceswatermangroves
September weather nearby: Sapeaçu 27 km · Conceição do Almeida 28 km · Santo Antônio de Jesus 29 km · Itatim 30 km · Amargosa 35 km · Cabaceiras do Paraguaçu 36 km · Cruz das Almas 37 km · São Felipe 38 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

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 Castro Alves (-12.7656°, -39.4283°, elevation 255 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).