Altônia weather in September

In September, Altônia sees average daytime highs of 27°C and overnight lows near 18°C, with 115 mm of rain across 8.5 wet days and about 11.9 hours of daylight. It is the 8th-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 49% 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 Altônia's 3rd-clearest and 2nd-windiest month. For the whole year in context, see Altônia's year-round climate.

Daytime high
27°
8th warmest
Overnight low
18°
5th coldest
Rainfall
115 mm
8.5 wet days
Daylight
11 h 54 min
7:34 AM – 7:26 PM
Cloud cover
46%
3rd clearest
Wind
11 km/h
2nd windiest
Solar energy
5.05 kWh/m²
Travel score
6.9
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical September day in Altônia reaches about 27°C in the afternoon and slips back to 18°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 33°C. Set against its neighbours, September runs about 2°C warmer than August and about 2°C cooler than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12717
22717
32717
42718
52718
62718
72718
82718
92718
102718
112718
122718
132718
142718
152718
162718
172718
182718
192718
202718
212718
222719
232719
242719
252719
262719
272719
282819
292819
302819

How September really feels in Altônia

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.

Altônia weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°14416.613.33.9
Feb31° / 23°14314.612.84.0
Mar30° / 22°10712.712.24.7
Apr28° / 20°917.711.56.4
May24° / 17°1258.810.97.2
Jun23° / 16°1078.110.67.4
Jul23° / 15°846.910.77.6
Aug25° / 16°826.211.27.8
Sep27° / 18°1158.511.96.9
Oct29° / 20°16012.112.65.4
Nov30° / 21°13711.713.25.0
Dec30° / 23°1541513.44.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 40%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17228
27129
37030
46931
56832
66733
76634
86535
96535
106337
116337
126238
136238
146238
156139
166139
176040
186040
195941
205941
215842
225644
235545
245446
255347
265248
275149
285050
294951
304951

Chance of precipitation in September

Any precipitation

Altônia gets around 115 mm of rain over 8.5 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 28% and peaks near 36% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
122
223
323
424
524
625
725
825
926
1026
1126
1226
1326
1427
1527
1627
1728
1828
1928
2029
2130
2230
2331
2432
2533
2634
2734
2835
2935
3036

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 33% 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 (%)
122413070
222403080
321403180
420403190
5204031100
6193931100
7193932110
8183832120
9183832130
10173733130
11173633140
12173534150
13163434160
14163335160
15163235170
16153035181
17152936191
18152836201
19152735221
20142635231
21142535241
22132535261
23132435271
24122335292
25112234312
26102234332
27102133342
2892033362
2992032382
3081932392

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 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 7:50 AM to 7:19 AM, and sunset from 7:21 PM to 7:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:507:21
211.57:497:21
311.67:487:21
411.67:477:22
511.67:467:22
611.67:457:22
711.77:447:23
811.77:437:23
911.77:427:23
1011.77:417:24
1111.77:397:24
1211.87:387:24
1311.87:377:25
1411.87:367:25
1511.87:357:25
1611.97:347:26
1711.97:337:26
1811.97:327:27
1911.97:317:27
2012.07:307:27
2112.07:297:28
2212.07:287:28
2312.07:267:28
2412.17:257:29
2512.17:247:29
2612.17:237:29
2712.17:227:30
2812.17:217:30
2912.27:207:30
3012.27:197:31

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.05 kWh/m².

For context, solar energy here swings from a low near 3.12 kWh/m² to a high of 6.28 kWh/m² in December across the year — September's 5.05 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.9Bright
54.9Bright
64.9Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.1Bright
245.1Bright
255.2Bright
265.2Bright
275.2Bright
285.2Bright
295.2Bright
305.2Bright
Planning a trip in September

Is September a good time to visit Altônia?

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

6.9
Sightseeing
5th-best month of the year
7.0
Beach & pool
3rd-best month of the year

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

What to pack for Altônia in September

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

In September, Altônia sees daytime highs around 27°C and nights near 18°C. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Altônia in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Altônia peaks around January 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near September 14 at about 5 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighExtremeJan 19UV 15Sep 14UV 5
UV index (midday)Level
Jan15Extreme
Feb14Extreme
Mar12Extreme
Apr9Very high
May6High
Jun5High
Jul5High
Aug7Very high
Sep4Moderate
Oct11Extreme
Nov12Extreme
Dec14Extreme

Air quality in Altônia 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 Altônia is worst in September — around 26 µg/m³ PM2.5 (moderate), about 4.7× the cleanest month (March, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1525 µg/m³Mar 166 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb7Good
Mar6Good
Apr7Good
May8Good
Jun8Good
Jul7Good
Aug17Moderate
Sep26Moderate
Oct13Moderate
Nov9Good
Dec7Good
Location & terrain

Where is Altônia?

Altônia sits at 23.9°S, 53.9°W, 353 m above sea level, in Brazil. The nearest listed city is Iporã, 25 km away.

Topography around Altônia

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

Within 3 km, the terrain around Altônia has only modest variations in elevation — a maximum elevation change of 114 m around an average of 353 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 216 m; within 80 km, significant variations in elevation — a maximum elevation change of 297 m.

The land around Altônia is covered by grassland (36%) and cropland (36%) within 3 km, cropland (40%) and grassland (38%) within 16 km, and cropland (58%) and grassland (22%) within 80 km.

3 km
114 m
16 km
216 m
80 km
297 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Iporã 25 km · Terra Roxa 37 km · Guaíra 42 km · Palotina 46 km · Itaquiraí 53 km · Umuarama 60 km · Assis Chateaubriand 72 km · Marechal Cândido Rondon 77 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 Altônia (-23.8744°, -53.9017°, elevation 353 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).