Alto Alegre weather in September

In September, Alto Alegre sees average daytime highs of 32°C and overnight lows near 23°C, with 118 mm of rain across 18.3 wet days and about 12 hours of daylight. It is the 6th-warmest and 7th-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 35% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 06 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Alto Alegre's 1st-clearest and 9th-windiest month. For the whole year in context, see Alto Alegre's year-round climate.

Daytime high
32°
6th warmest
Overnight low
23°
5th coldest
Rainfall
118 mm
18.3 wet days
Daylight
12 hours
6:00 AM – 6:01 PM
Cloud cover
55%
1st clearest
Wind
5 km/h
9th windiest
Solar energy
5.62 kWh/m²
Travel score
3.4
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 Alto Alegre reaches about 32°C in the afternoon and slips back to 23°C overnight — a 9°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 2°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
83223
93223
103223
113223
123223
133223
143223
153223
163223
173223
183223
193223
203223
213223
223223
233223
243223
253223
263223
273223
283223
293223
303223

How September really feels in Alto Alegre

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.

Alto Alegre weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 24°588.611.94.0
Feb33° / 24°517.511.93.7
Mar33° / 24°8410123.4
Apr32° / 24°24019.112.13.1
May30° / 23°40627.512.13.0
Jun29° / 22°3722812.23.1
Jul29° / 22°30028.712.23.1
Aug30° / 23°20125.312.13.2
Sep32° / 23°11818.3123.4
Oct32° / 23°1041511.93.4
Nov32° / 23°12816.611.93.3
Dec32° / 24°9813.511.83.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 22% of September, with mostly cloudy or overcast conditions the remaining 42%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25743
35842
45842
55743
65743
75743
85743
95743
105743
115743
125743
135743
145743
155743
165743
175743
185842
195743
205743
215842
225842
235842
245842
255941
265941
275941
285842
295842
305842

Chance of precipitation in September

Any precipitation

Alto Alegre gets around 118 mm of rain over 18.3 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 60% and peaks near 71% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
171
270
370
469
569
668
768
868
967
1067
1166
1265
1364
1463
1562
1661
1760
1859
1958
2057
2156
2254
2353
2452
2551
2650
2749
2848
2947
3047

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 79% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
108119
208119
308119
408119
517920
617920
717920
817920
917920
1017821
1117821
1217821
1317821
1417821
1517821
1617821
1717821
1817821
1917821
2017821
2127721
2227721
2327820
2427820
2537819
2637819
2737819
2847818
2947818
3047917

Wind in September

Winds average 5 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
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

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

Days shrink by about 6 minutes over September. Sunrise moves from 6:04 AM to 5:56 AM, and sunset from 6:07 PM to 5:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.16:046:07
212.16:046:07
312.16:046:07
412.06:036:06
512.06:036:06
612.06:036:05
712.06:026:05
812.06:026:04
912.06:026:04
1012.06:026:03
1112.06:016:03
1212.06:016:03
1312.06:016:02
1412.06:006:02
1512.06:006:01
1612.06:006:01
1712.06:006:00
1812.05:596:00
1912.05:595:59
2012.05:595:59
2112.05:585:59
2212.05:585:58
2312.05:585:58
2412.05:585:57
2512.05:575:57
2612.05:575:56
2712.05:575:56
2812.05:565:55
2912.05:565:55
3012.05:565:55

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.62 kWh/m².

For context, solar energy here swings from a low near 3.75 kWh/m² to a high of 5.73 kWh/m² in March across the year — September's 5.62 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.6Bright
185.7Bright
195.7Bright
205.7Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.7Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Hazard calendar for Alto Alegre

In seasonPeak

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

Alto Alegre's monsoon runs April–August, when most of the year's rain falls.

Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Alto Alegre?

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

3.4
Sightseeing
4th-best month of the year
5.3
Beach & pool
7th-best month of the year

September is a weaker month for outdoor sightseeing in Alto Alegre.

What to pack for Alto Alegre in September

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

In September, Alto Alegre sees daytime highs around 32°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 18 days see rain.

light clothesrain gearsun protection

UV index in Alto Alegre 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 Alto Alegre peaks around March 21 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 18 at about 11 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 21UV 14Nov 18UV 11
UV index (midday)Level
Jan13Extreme
Feb13Extreme
Mar14Extreme
Apr14Extreme
May13Extreme
Jun12Extreme
Jul11Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec11Extreme

Air quality in Alto Alegre 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 Alto Alegre is worst in March — around 24 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (December, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2124 µg/m³Dec 1112 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb18Moderate
Mar24Moderate
Apr22Moderate
May16Moderate
Jun14Moderate
Jul13Moderate
Aug12Moderate
Sep12Moderate
Oct13Moderate
Nov12Moderate
Dec12Moderate
Location & terrain

Where is Alto Alegre?

Alto Alegre sits at 2.9°N, 61.5°W, 83 m above sea level, in Brazil. The nearest listed city is Mucajaí, 83 km away.

Rorainópolis

Topography around Alto Alegre

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

Within 3 km, the terrain around Alto Alegre has only modest variations in elevation — a maximum elevation change of 61 m around an average of 93 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 147 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,411 m.

The land around Alto Alegre is covered by trees (70%) and grassland (22%) within 3 km, trees (69%) and grassland (29%) within 16 km, and trees (68%) and grassland (30%) within 80 km.

3 km
61 m
16 km
147 m
80 km
1,411 m
treesshrubsgrasslandcroplandwaterwetland
September weather nearby: Mucajaí 83 km · Boa Vista 92 km · Cantá 105 km · Caracaraí 127 km · Pacaraima 175 km · Santa Elena de Uairén 195 km · Lethem 196 km · Rorainópolis 248 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 Alto Alegre (2.8958°, -61.4975°, elevation 83 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).