Casimiro de Abreu weather in September

In September, Casimiro de Abreu sees average daytime highs of 25°C and overnight lows near 17°C, with 104 mm of rain across 12.9 wet days and about 11.9 hours of daylight. It is the 8th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 34% of the time in September, and the air most often feels humid.

Daylight stretches from about 11 h 30 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Casimiro de Abreu's 6th-clearest and 1st-windiest month. For the whole year in context, see Casimiro de Abreu's year-round climate.

Daytime high
25°
8th warmest
Overnight low
17°
5th coldest
Rainfall
104 mm
12.9 wet days
Daylight
11 h 54 min
6:47 AM – 6:39 PM
Cloud cover
58%
6th clearest
Wind
10 km/h
1st windiest
Solar energy
4.88 kWh/m²
Travel score
6.4
out of 10

Casimiro de Abreu 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 25°C through the month.

A typical September day in Casimiro de Abreu reaches about 25°C in the afternoon and slips back to 17°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 30°C. Set against its neighbours, September runs on par with August and about 1°C cooler than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12516
22516
32516
42517
52517
62517
72517
82517
92517
102517
112517
122517
132517
142517
152517
162517
172517
182517
192517
202517
212517
222517
232517
242517
252517
262517
272517
282518
292518
302518

How September really feels in Casimiro de Abreu

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.

Casimiro de Abreu weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 21°29121.613.24.0
Feb29° / 21°21016.812.84.2
Mar28° / 21°24021.512.24.3
Apr27° / 19°11914.911.55.8
May25° / 17°7912.210.96.6
Jun24° / 16°437.310.77.6
Jul24° / 15°407.410.87.7
Aug25° / 16°488.211.27.4
Sep25° / 17°10412.911.96.4
Oct26° / 18°1541612.55.6
Nov26° / 19°27521.213.14.7
Dec28° / 21°30822.913.44.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 11% of September, with mostly cloudy or overcast conditions the remaining 55%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16139
26139
36040
46040
55941
65743
75644
85545
95446
105347
115050
125050
134951
144654
154555
164456
174357
184258
194060
203961
213862
223763
233664
243466
253466
263466
273367
283367
293268
303268

Chance of precipitation in September

Any precipitation

Casimiro de Abreu gets around 104 mm of rain over 12.9 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 42% and peaks near 53% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
131
232
332
433
533
634
735
835
936
1037
1138
1239
1339
1440
1541
1642
1743
1844
1945
2046
2147
2248
2349
2450
2550
2651
2752
2852
2952
3053

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 21% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
16305590
26305590
363054100
462955100
562954110
662854120
762854120
852755130
952754140
1052654150
1152653160
1242554170
1342553180
1442453190
1532453200
1632353210
1732352220
1832351230
1942249240
2042248260
2142247270
2242246280
2342245290
2442144300
2552143310
2652043320
2752042330
2851941341
2951941351
3041940361

Wind in September

Winds average 10 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 10 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 30 min at the start of September to 12 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over September. Sunrise moves from 7:02 AM to 6:33 AM, and sunset from 6:35 PM to 6:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:026:35
211.67:016:35
311.67:006:35
411.66:596:36
511.66:586:36
611.76:576:36
711.76:566:37
811.76:556:37
911.76:546:37
1011.76:536:38
1111.86:526:38
1211.86:516:38
1311.86:506:38
1411.86:496:39
1511.86:486:39
1611.96:476:39
1711.96:466:40
1811.96:456:40
1911.96:446:40
2012.06:436:40
2112.06:426:41
2212.06:416:41
2312.06:406:41
2412.16:396:42
2512.16:386:42
2612.16:376:42
2712.16:366:43
2812.16:356:43
2912.26:346:43
3012.26:336:44

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.88 kWh/m².

For context, solar energy here swings from a low near 3.54 kWh/m² to a high of 6.21 kWh/m² in February across the year — September's 4.88 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.8Bright
54.9Bright
64.9Bright
74.9Bright
84.9Bright
94.9Bright
104.9Bright
114.9Bright
124.9Bright
134.9Bright
144.9Bright
154.9Bright
164.9Bright
174.9Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
224.9Bright
234.9Bright
244.9Bright
254.9Bright
264.9Bright
275.0Bright
285.0Bright
295.0Bright
305.0Bright
Planning a trip in September

Hazard calendar for Casimiro de Abreu

In seasonPeak

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

Casimiro de Abreu's rainy season runs October–March, 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 Casimiro de Abreu?

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

6.4
Sightseeing
5th-best month of the year
5.8
Beach & pool
5th-best month of the year

September is a reasonable time to visit Casimiro de Abreu for sightseeing.

What to pack for Casimiro de Abreu in September

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

In September, Casimiro de Abreu sees daytime highs around 25°C and nights near 17°C. Worth packing: light clothes, rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

Sea temperature near Casimiro de Abreu 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 37 km away) is warmest in March at about 25°C and coldest in September near 21°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan24Refreshing
Feb24Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug22Refreshing
Sep21Refreshing
Oct22Refreshing
Nov22Refreshing
Dec24Refreshing

UV index in Casimiro de Abreu 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 Casimiro de Abreu peaks around January 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 17UV 14Jul 11UV 6
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar13Extreme
Apr10Very high
May7High
Jun6High
Jul6High
Aug8Very high
Sep7Very high
Oct12Extreme
Nov14Extreme
Dec14Extreme
Location & terrain

Where is Casimiro de Abreu?

Casimiro de Abreu sits at 22.5°S, 42.2°W, 23 m above sea level, in Brazil. The nearest listed city is Silva Jardim, 27 km away.

Topography around Casimiro de Abreu

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

Within 3 km, the terrain around Casimiro de Abreu has significant variations in elevation — a maximum elevation change of 480 m around an average of 71 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,325 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,252 m.

The land around Casimiro de Abreu is covered by trees (51%) and grassland (39%) within 3 km, trees (59%) and grassland (32%) within 16 km, and trees (37%), grassland (31%) and water (30%) within 80 km.

3 km
480 m
16 km
1,325 m
80 km
2,252 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Silva Jardim 27 km · Rio das Ostras 27 km · Iguaba Grande 40 km · Nova Friburgo 40 km · São Pedro da Aldeia 41 km · Bom Jardim 43 km · Buzios 44 km · Macaé 45 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 Casimiro de Abreu (-22.4806°, -42.2042°, elevation 23 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).