São Mateus do Sul weather in September

In September, São Mateus do Sul sees average daytime highs of 23°C and overnight lows near 12°C, with 140 mm of rain across 11 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 23°C through the month. The sky is clear or mostly clear about 31% of the time in September, and the air most often feels dry.

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 São Mateus do Sul's 4th-clearest and 1st-windiest month. For the whole year in context, see São Mateus do Sul's year-round climate.

Daytime high
23°
8th warmest
Overnight low
12°
5th coldest
Rainfall
140 mm
11 wet days
Daylight
11 h 54 min
7:20 AM – 7:11 PM
Cloud cover
63%
4th clearest
Wind
10 km/h
1st windiest
Solar energy
4.32 kWh/m²
Travel score
6.5
out of 10

São Mateus do Sul is 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 23°C through the month.

A typical September day in São Mateus do Sul reaches about 23°C in the afternoon and slips back to 12°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 29°C. Set against its neighbours, September runs about 1°C warmer than August and about 1°C cooler than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12311
22311
32312
42312
52312
62312
72312
82312
92312
102312
112312
122312
132312
142312
152312
162312
172312
182312
192313
202313
212313
222313
232313
242313
252313
262313
272313
282313
292313
302313

São Mateus do Sul weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 18°18421.213.44.7
Feb27° / 18°15719.112.94.8
Mar26° / 17°10814.512.25.8
Apr24° / 15°769.311.46.8
May21° / 12°1059.210.86.5
Jun20° / 10°1099.110.46.3
Jul20° / 858.310.56.5
Aug22° / 10°857.711.17.1
Sep23° / 12°1401111.86.5
Oct24° / 14°15015.212.65.9
Nov25° / 16°1231413.36.0
Dec27° / 17°14417.213.65.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% 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 58%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25644
35545
45446
55248
65149
75050
84852
94753
104753
114654
124555
134456
144456
154357
164159
174159
184060
193862
203862
213763
223664
233664
243466
253367
263367
273268
283268
293070
303070

Chance of precipitation in September

Any precipitation

São Mateus do Sul gets around 140 mm of rain over 11 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 36% and peaks near 47% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
125
225
326
427
527
628
729
830
931
1032
1133
1233
1334
1435
1536
1637
1738
1839
1940
2040
2141
2242
2343
2444
2544
2645
2745
2846
2947
3047

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 47% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1573760
2563770
3553870
4543880
5533890
6523990
75139100
85139100
95039110
104940110
114840120
124840120
134740131
144640131
154640141
164639141
174639151
184639151
194538151
204538161
214538161
224438171
234437181
244337191
254237201
264137211
274036221
283936231
293836241
303736252

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 7:37 AM to 7:04 AM, and sunset from 7:05 PM to 7:17 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:377:05
211.57:367:06
311.57:357:06
411.57:347:06
511.67:337:07
611.67:327:07
711.67:317:08
811.67:307:08
911.77:287:09
1011.77:277:09
1111.77:267:09
1211.77:257:10
1311.87:247:10
1411.87:237:11
1511.87:227:11
1611.97:207:11
1711.97:197:12
1811.97:187:12
1911.97:177:13
2012.07:167:13
2112.07:157:13
2212.07:137:14
2312.07:127:14
2412.17:117:15
2512.17:107:15
2612.17:097:16
2712.17:087:16
2812.27:077:16
2912.27:067:17
3012.27:047:17

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.32 kWh/m².

For context, solar energy here swings from a low near 2.78 kWh/m² to a high of 5.75 kWh/m² in December across the year — September's 4.32 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.4Bright
34.4Bright
44.4Bright
54.4Bright
64.4Bright
74.4Bright
84.4Bright
94.4Bright
104.4Bright
114.4Bright
124.4Bright
134.4Bright
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.4Bright
194.4Bright
204.4Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.3Bright
264.3Bright
274.3Bright
284.3Bright
294.3Bright
304.3Bright
Planning a trip in September

Is September a good time to visit São Mateus do Sul?

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

6.5
Sightseeing
3rd-best month of the year
4.9
Beach & pool
6th-best month of the year

September is a reasonable time to visit São Mateus do Sul for sightseeing.

What to pack for São Mateus do Sul in September

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

In September, São Mateus do Sul sees daytime highs around 23°C and nights near 12°C. Worth packing: light clothes and rain gear. About 11 days see rain.

light clothesrain gear

UV index in São Mateus do Sul in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in São Mateus do Sul peaks around January 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 19UV 15Jul 12UV 5
UV index (midday)Level
Jan15Extreme
Feb14Extreme
Mar12Extreme
Apr9Very high
May6High
Jun5High
Jul5High
Aug6High
Sep8Very high
Oct11Extreme
Nov13Extreme
Dec14Extreme

Air quality in São Mateus do Sul 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 São Mateus do Sul is worst in September — around 16 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1315 µg/m³Dec 197 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar7Good
Apr8Good
May9Good
Jun8Good
Jul10Good
Aug13Moderate
Sep16Moderate
Oct10Good
Nov8Good
Dec7Good
Location & terrain

Where is São Mateus do Sul?

São Mateus do Sul sits at 25.9°S, 50.4°W, 792 m above sea level, in Brazil. The nearest listed city is Três Barras, 27 km away.

Topography around São Mateus do Sul

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of São Mateus do Sul.

Within 3 km, the terrain around São Mateus do Sul has only modest variations in elevation — a maximum elevation change of 80 m around an average of 775 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 159 m; within 80 km, large variations in elevation — a maximum elevation change of 879 m.

The land around São Mateus do Sul is covered by trees (40%), grassland (22%) and artificial surfaces (20%) within 3 km, trees (56%) and cropland (32%) within 16 km, and trees (60%) and cropland (33%) within 80 km.

3 km
80 m
16 km
159 m
80 km
879 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Três Barras 27 km · Canoinhas 34 km · Irati 53 km · Papanduva 60 km · Palmeira 62 km · Mafra 63 km · Rio Negro 64 km · Lapa 68 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 São Mateus do Sul (-25.8742°, -50.3828°, elevation 792 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).