Rorainópolis weather in September

In September, Rorainópolis sees average daytime highs of 32°C and overnight lows near 23°C, with 147 mm of rain across 20.6 wet days and about 12 hours of daylight. It is the 2nd-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 23% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Rorainópolis's 1st-clearest and 8th-windiest month. For the whole year in context, see Rorainópolis's year-round climate.

Daytime high
32°
2nd warmest
Overnight low
23°
6th coldest
Rainfall
147 mm
20.6 wet days
Daylight
12 hours
5:56 AM – 5:56 PM
Cloud cover
64%
1st clearest
Wind
4 km/h
8th windiest
Solar energy
5.33 kWh/m²
Travel score
3.1
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical September day in Rorainópolis reaches about 32°C in the afternoon and slips back to 23°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 34°C. Set against its neighbours, September runs about 1°C warmer than August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13123
23123
33123
43123
53123
63123
73123
83123
93123
103123
113123
123123
133123
143223
153223
163223
173223
183223
193223
203223
213223
223223
233223
243223
253223
263223
273223
283223
293223
303223

How September really feels in Rorainópolis

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.

Rorainópolis weather by month

How September compares with the rest of the year at a glance. September is the 2nd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°11715123.8
Feb31° / 24°10813.2123.7
Mar31° / 24°18418.1123.5
Apr30° / 23°34824.7123.1
May29° / 23°45629.4122.9
Jun29° / 23°34128.412.12.9
Jul29° / 22°24828.2123.1
Aug30° / 23°18525.1123.2
Sep32° / 23°14720.6123.1
Oct32° / 23°12918.5123.2
Nov31° / 23°16120.4123.1
Dec31° / 23°16119.911.93.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14456
24456
34456
44456
54456
64357
74357
84357
94357
104357
114357
124357
134357
144357
154357
164258
174357
184357
194258
204258
214159
224159
234060
244159
254159
264060
274060
284060
294060
303961

Chance of precipitation in September

Any precipitation

Rorainópolis gets around 147 mm of rain over 20.6 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 69% and peaks near 78% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
178
278
377
476
576
675
775
874
973
1073
1172
1271
1371
1470
1569
1669
1768
1867
1966
2066
2165
2264
2363
2462
2561
2660
2760
2859
2959
3058

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 56% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
105941
205842
305842
405842
505842
605842
705842
805842
905842
1005842
1105842
1205842
1305743
1405743
1505743
1605743
1705743
1805644
1915544
2015544
2115544
2215544
2315544
2415544
2515544
2615544
2715544
2815544
2915544
3015544

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

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

Days grow by about 0 minutes over September. Sunrise moves from 6:01 AM to 5:51 AM, and sunset from 6:02 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.06:016:02
212.06:016:02
312.06:006:01
412.06:006:01
512.06:006:00
612.05:596:00
712.05:596:00
812.05:595:59
912.05:585:59
1012.05:585:59
1112.05:585:58
1212.05:575:58
1312.05:575:57
1412.05:575:57
1512.05:565:57
1612.05:565:56
1712.05:555:56
1812.05:555:55
1912.05:555:55
2012.05:545:55
2112.05:545:54
2212.05:545:54
2312.05:535:53
2412.05:535:53
2512.05:535:53
2612.05:525:52
2712.05:525:52
2812.05:525:51
2912.05:525:51
3012.05:515:51

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.33 kWh/m².

For context, solar energy here swings from a low near 3.53 kWh/m² to a high of 5.36 kWh/m² in October across the year — September's 5.33 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.4Bright
185.4Bright
195.4Bright
205.4Bright
215.4Bright
225.4Bright
235.4Bright
245.4Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.4Bright
305.4Bright
Planning a trip in September

Hazard calendar for Rorainópolis

In seasonPeak

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

Rorainópolis's rainy season runs April–July, 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 Rorainópolis?

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

3.1
Sightseeing
7th-best month of the year
4.8
Beach & pool
6th-best month of the year

September is a weaker month for outdoor sightseeing in Rorainópolis.

What to pack for Rorainópolis in September

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

In September, Rorainópolis sees daytime highs around 32°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

light clothesrain gearsun protection

UV index in Rorainópolis 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 Rorainópolis peaks around March 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 16 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeExtremeMar 19UV 15Nov 16UV 10
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar15Extreme
Apr15Extreme
May12Extreme
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep12Extreme
Oct11Extreme
Nov10Very high
Dec11Extreme

Air quality in Rorainópolis 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 Rorainópolis is worst in March — around 33 µg/m³ PM2.5 (moderate), about 3.6× the cleanest month (July, 9 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateMar 1732 µg/m³Jul 119 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb24Moderate
Mar33Moderate
Apr25Moderate
May11Good
Jun9Good
Jul9Good
Aug11Good
Sep12Good
Oct14Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Rorainópolis?

Rorainópolis sits at 0.9°N, 60.4°W, 82 m above sea level, in Brazil. The nearest listed city is Caracaraí, 125 km away.

Alto AlegreLethemPresidente FigueiredoBarcelos

Topography around Rorainópolis

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

Within 3 km, the terrain around Rorainópolis has only modest variations in elevation — a maximum elevation change of 49 m around an average of 87 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 226 m; within 80 km, large variations in elevation — a maximum elevation change of 858 m.

The land around Rorainópolis is covered by grassland (46%) and trees (45%) within 3 km, trees (66%) and grassland (34%) within 16 km, and trees (81%) within 80 km.

3 km
49 m
16 km
226 m
80 km
858 m
treesgrasslandartificial surfaceswetland
September weather nearby: Caracaraí 125 km · Mucajaí 175 km · Cantá 186 km · Boa Vista 210 km · Alto Alegre 248 km · Lethem 278 km · Presidente Figueiredo 334 km · Barcelos 351 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 Rorainópolis (0.9461°, -60.4181°, elevation 82 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).