São Borja weather in September

In September, São Borja sees average daytime highs of 24°C and overnight lows near 14°C, with 151 mm of rain across 10.1 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 24°C through the month. The sky is clear or mostly clear about 43% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 24 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 Borja's 9th-clearest and 1st-windiest month. For the whole year in context, see São Borja's year-round climate.

Daytime high
24°
8th warmest
Overnight low
14°
5th coldest
Rainfall
151 mm
10.1 wet days
Daylight
11 h 48 min
7:43 AM – 7:33 PM
Cloud cover
51%
9th clearest
Wind
14 km/h
1st windiest
Solar energy
4.57 kWh/m²
Travel score
7.0
out of 10

São Borja 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 24°C through the month.

A typical September day in São Borja reaches about 24°C in the afternoon and slips back to 14°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 31°C. Set against its neighbours, September runs about 2°C warmer than August and about 3°C cooler than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12413
22413
32413
42413
52413
62413
72413
82413
92413
102413
112413
122414
132414
142414
152414
162414
172414
182414
192414
202414
212414
222414
232414
242514
252514
262514
272515
282515
292515
302515

How September really feels in São Borja

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.

São Borja weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 22°15911.913.63.9
Feb31° / 21°13211.2134.3
Mar30° / 20°12810.212.25.2
Apr27° / 17°16510.111.36.7
May23° / 14°1198.310.67.1
Jun21° / 12°1179.210.26.5
Jul20° / 11°1138.810.46.7
Aug23° / 12°1038.5117.2
Sep24° / 14°15110.111.87.0
Oct27° / 16°21011.512.76.4
Nov29° / 18°155913.45.7
Dec31° / 20°15710.613.84.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% 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 46%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25941
35842
45743
55743
65545
75545
85446
95446
105446
115347
125347
135347
145347
155347
165347
175347
185347
195347
205446
215446
225347
235347
245446
255347
265347
275248
285149
295149
305050

Chance of precipitation in September

Any precipitation

São Borja gets around 151 mm of rain over 10.1 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 34% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
132
232
333
433
533
633
733
833
933
1033
1133
1233
1334
1434
1534
1634
1734
1834
1934
2033
2134
2234
2334
2434
2535
2635
2735
2835
2936
3036

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 44% of days. Sticky, muggy-or-worse air turns up on roughly 10% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
148212560
247202570
347202570
447212580
547212580
646212580
746212580
846222480
946222480
1046222480
1145222480
1245232490
1345232390
1445232390
1544232390
1644242390
1744242290
1844242290
19442422101
20442521101
21432521101
22432521101
23422521111
24412521111
25402521121
26392621131
27382622131
28382622141
29372622151
30362622151

Wind in September

Winds average 14 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 14 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 24 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 48 minutes over September. Sunrise moves from 8:02 AM to 7:26 AM, and sunset from 7:26 PM to 7:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.48:027:26
211.48:017:26
311.57:597:27
411.57:587:27
511.57:577:28
611.57:567:28
711.67:557:29
811.67:537:29
911.67:527:30
1011.77:517:30
1111.77:507:31
1211.77:487:31
1311.77:477:32
1411.87:467:32
1511.87:457:33
1611.87:437:33
1711.97:427:34
1811.97:417:34
1911.97:407:35
2011.97:387:35
2112.07:377:36
2212.07:367:36
2312.07:357:37
2412.17:337:37
2512.17:327:38
2612.17:317:38
2712.27:307:39
2812.27:287:40
2912.27:277:40
3012.27:267:41

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.57 kWh/m².

For context, solar energy here swings from a low near 2.53 kWh/m² to a high of 6.86 kWh/m² in December across the year — September's 4.57 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.2Bright
44.2Bright
54.3Bright
64.3Bright
74.3Bright
84.3Bright
94.4Bright
104.4Bright
114.4Bright
124.4Bright
134.5Bright
144.5Bright
154.5Bright
164.6Bright
174.6Bright
184.7Bright
194.7Bright
204.7Bright
214.8Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.9Bright
274.9Bright
284.9Bright
294.9Bright
304.9Bright
Planning a trip in September

Is September a good time to visit São Borja?

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

7.0
Sightseeing
3rd-best month of the year
6.0
Beach & pool
8th-best month of the year

September is one of the better times to visit São Borja for general sightseeing.

What to pack for São Borja in September

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

In September, São Borja sees daytime highs around 24°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in São Borja 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 Borja peaks around January 21 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighExtremeJan 21UV 14Jun 19UV 3
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar11Extreme
Apr8Very high
May5Moderate
Jun3Moderate
Jul4Moderate
Aug5Moderate
Sep8Very high
Oct5High
Nov11Extreme
Dec12Extreme

Air quality in São Borja 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 Borja is worst in September — around 16 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (March, 6 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodSep 1116 µg/m³Mar 226 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb14Moderate
Mar6Good
Apr7Good
May6Good
Jun7Good
Jul10Good
Aug15Moderate
Sep16Moderate
Oct9Good
Nov9Good
Dec6Good
Location & terrain

Where is São Borja?

São Borja sits at 28.7°S, 56.0°W, 98 m above sea level, in Brazil. The nearest listed city is Santo Tomé, 13 km away.

Topography around São Borja

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

Within 3 km, the terrain around São Borja has only modest variations in elevation — a maximum elevation change of 43 m around an average of 79 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 80 m; within 80 km, significant variations in elevation — a maximum elevation change of 276 m.

The land around São Borja is covered by artificial surfaces (26%) and cropland (24%) within 3 km, cropland (47%) within 16 km, and grassland (39%) and cropland (25%) within 80 km.

3 km
43 m
16 km
80 m
80 km
276 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Santo Tomé 13 km · Gobernador Virasora 68 km · Itaqui 74 km · Apóstoles 87 km · São Luiz Gonzaga 106 km · Santiago 125 km · Alegrete 127 km · São Francisco de Assis 130 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 Borja (-28.6606°, -56.0044°, elevation 98 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).