Caicó weather in September

In September, Caicó sees average daytime highs of 35°C and overnight lows near 22°C, with 1 mm of rain across 0.1 wet days and about 12 hours of daylight. It is the 5th-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 35°C through the month. The sky is clear or mostly clear about 73% of the time in September, and the air most often feels humid.

Daylight stretches from about 11 h 54 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Caicó's 1st-clearest and 1st-windiest month. For the whole year in context, see Caicó's year-round climate.

Daytime high
35°
5th warmest
Overnight low
22°
3rd coldest
Rainfall
1 mm
0.1 wet days
Daylight
12 hours
5:24 AM – 5:22 PM
Cloud cover
29%
1st clearest
Wind
20 km/h
1st windiest
Solar energy
6.73 kWh/m²
Travel score
3.4
out of 10

Caicó 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

Day-to-day highs hold fairly steady near 35°C through the month.

A typical September day in Caicó reaches about 35°C in the afternoon and slips back to 22°C overnight — a 13°C spread between the day's warmth and the night's chill. On most days the high lands between 33°C and 36°C. Set against its neighbours, September runs about 2°C warmer than August and about 1°C cooler than October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13421
23421
33422
43422
53422
63422
73422
83422
93422
103422
113522
123522
133522
143522
153522
163522
173522
183522
193522
203522
213522
223522
233522
243522
253522
263522
273622
283622
293622
303622

How September really feels in Caicó

Once humidity and wind are folded in, September averages 30 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
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Caicó weather by month

How September compares with the rest of the year at a glance. September is the 5th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan35° / 24°59712.32.6
Feb35° / 24°568.412.22.6
Mar34° / 24°10111.8122.7
Apr34° / 24°6710.311.93.1
May33° / 23°305.511.73.6
Jun32° / 22°193.411.64.4
Jul32° / 21°12211.74.6
Aug33° / 21°50.411.84.3
Sep35° / 22°10.1123.4
Oct36° / 23°40.312.12.7
Nov36° / 23°10.212.32.5
Dec36° / 24°111.912.42.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 73% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 11%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18812
28812
38812
48713
58713
68713
78614
88614
98614
108614
118614
128614
138614
148614
158614
168713
178713
188911
198911
209010
219010
22919
23919
24928
25928
26928
27937
28937
29928
30919

Chance of precipitation in September

Any precipitation

Caicó gets around 1 mm of rain over 0.1 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 0% and peaks near 0% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300

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 79% of days. Sticky, muggy-or-worse air turns up on roughly 10% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)
1127612
2127612
3137512
4137512
5137512
6137512
7137611
8137611
9137611
10137611
11137611
12137710
13137710
14127810
1512799
1612799
1712808
1811818
1911818
2011818
2111818
2211818
2311818
2411818
2511818
2611818
2711818
2811818
2911809
3010819

Wind in September

Winds average 20 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 19 km/h on the calmest days to 20 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
120light breeze
220breezy
320breezy
420breezy
520breezy
620breezy
720breezy
820breezy
920breezy
1020breezy
1120light breeze
1220light breeze
1320light breeze
1420light breeze
1520light breeze
1620light breeze
1720light breeze
1820light breeze
1920light breeze
2020light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2919light breeze
3019light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 54 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 12 minutes over September. Sunrise moves from 5:32 AM to 5:16 AM, and sunset from 5:24 PM to 5:19 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.95:325:24
211.95:315:24
311.95:315:24
411.95:305:24
511.95:305:24
611.95:295:24
711.95:295:23
811.95:285:23
911.95:285:23
1011.95:275:23
1111.95:275:23
1211.95:265:22
1311.95:255:22
1412.05:255:22
1512.05:245:22
1612.05:245:22
1712.05:235:21
1812.05:235:21
1912.05:225:21
2012.05:225:21
2112.05:215:21
2212.05:205:21
2312.05:205:20
2412.05:195:20
2512.05:195:20
2612.05:185:20
2712.05:185:20
2812.05:175:20
2912.05:175:19
3012.15:165:19

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.73 kWh/m².

For context, solar energy here swings from a low near 4.72 kWh/m² to a high of 7.09 kWh/m² in October across the year — September's 6.73 kWh/m² sits near the top of that range.

02468151015202530
Solar energy (kWh/m²)Level
16.3Intense
26.4Intense
36.4Intense
46.4Intense
56.4Intense
66.4Intense
76.5Intense
86.5Intense
96.5Intense
106.5Intense
116.5Intense
126.6Intense
136.6Intense
146.7Intense
156.7Intense
166.7Intense
176.8Intense
186.8Intense
196.8Intense
206.9Intense
216.9Intense
227.0Intense
237.0Intense
247.0Intense
257.0Intense
267.1Intense
277.1Intense
287.1Intense
297.1Intense
307.1Intense
Planning a trip in September

Is September a good time to visit Caicó?

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

3.4
Sightseeing
5th-best month of the year
7.3
Beach & pool
4th-best month of the year

September is a weaker month for outdoor sightseeing in Caicó. The water and warmth also suit a beach or pool day.

What to pack for Caicó in September

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

In September, Caicó sees daytime highs around 35°C and nights near 22°C. Pack light clothes and sun protection.

light clothessun protection

UV index in Caicó in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Caicó peaks around March 13 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 17 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 13UV 15Jul 17UV 10
UV index (midday)Level
Jan13Extreme
Feb15Extreme
Mar15Extreme
Apr14Extreme
May11Extreme
Jun10Very high
Jul10Very high
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec12Extreme

Air quality in Caicó 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 Caicó is worst in October — around 21 µg/m³ PM2.5 (moderate), about 4.0× the cleanest month (July, 5 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateOct 1421 µg/m³Jul 95 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb9Good
Mar8Good
Apr8Good
May7Good
Jun6Good
Jul5Good
Aug13Moderate
Sep20Moderate
Oct21Moderate
Nov19Moderate
Dec16Moderate
Location & terrain

Where is Caicó?

Caicó sits at 6.5°S, 37.1°W, 161 m above sea level, in Brazil. The nearest listed city is Jucurutu, 48 km away.

Topography around Caicó

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

Within 3 km, the terrain around Caicó has only modest variations in elevation — a maximum elevation change of 54 m around an average of 162 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 499 m; within 80 km, large variations in elevation — a maximum elevation change of 867 m.

The land around Caicó is covered by shrubs (36%), grassland (31%) and artificial surfaces (27%) within 3 km, shrubs (69%) and grassland (26%) within 16 km, and shrubs (77%) within 80 km.

3 km
54 m
16 km
499 m
80 km
867 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Jucurutu 48 km · Parelhas 55 km · Patos 66 km · Currais Novos 68 km · Catolé do Rocha 73 km · São Bento 75 km · Lagoa Nova 80 km · Picuí 83 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 Caicó (-6.4583°, -37.0978°, elevation 161 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).