São João do Piauí weather in September

In September, São João do Piauí sees average daytime highs of 36°C and overnight lows near 24°C, with 2 mm of rain across 0.2 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 36°C through the month. The sky is clear or mostly clear about 74% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is São João do Piauí's 1st-clearest and 3rd-windiest month. For the whole year in context, see São João do Piauí's year-round climate.

Daytime high
36°
2nd warmest
Overnight low
24°
7th coldest
Rainfall
2 mm
0.2 wet days
Daylight
12 hours
5:45 AM – 5:42 PM
Cloud cover
28%
1st clearest
Wind
15 km/h
3rd windiest
Solar energy
6.74 kWh/m²
Travel score
2.8
out of 10

São João do Piauí 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 36°C through the month.

A typical September day in São João do Piauí reaches about 36°C in the afternoon and slips back to 24°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 34°C and 38°C. Set against its neighbours, September runs about 2°C warmer than August and on par with October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13523
23523
33523
43523
53523
63523
73523
83523
93523
103523
113623
123623
133623
143623
153623
163623
173624
183624
193624
203624
213624
223624
233624
243624
253624
263624
273624
283624
293624
303625

How September really feels in São João do Piauí

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.

São João do Piauí 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
Jan32° / 24°14716.512.43.2
Feb32° / 23°1391512.33.4
Mar32° / 23°13916.312.13.5
Apr32° / 23°749.911.83.8
May33° / 24°22311.64.0
Jun33° / 23°10.311.54.6
Jul33° / 22°10.211.64.6
Aug34° / 22°0011.73.8
Sep36° / 24°20.2122.8
Oct36° / 25°182.112.22.4
Nov35° / 25°556.312.42.8
Dec34° / 25°759.812.53.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 74% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 13%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18515
28515
38515
48515
58515
68515
78515
88515
98515
108614
118713
128713
138812
148812
158812
168911
179010
189010
19919
209010
219010
229010
239010
248911
258812
268812
278812
288713
298713
308713

Chance of precipitation in September

Any precipitation

São João do Piauí gets around 2 mm of rain over 0.2 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 1% and peaks near 2% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
10
20
30
40
50
60
70
80
90
100
110
120
130
140
151
161
171
181
191
201
211
221
232
242
252
262
272
282
292
302

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the comfortable band about 60% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
11366210
21366210
31366210
41365220
51365220
61364230
71364230
81363240
91362250
101362250
111361260
121361260
131360270
141261270
151260271
161260271
171160281
181160281
191160281
201159291
211060291
221059301
231058302
241057312
251057312
261056322
271056322
281055323
291054333
301054333

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 5:54 AM to 5:36 AM, and sunset from 5:44 PM to 5:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.85:545:44
211.85:535:44
311.95:525:44
411.95:525:44
511.95:515:43
611.95:515:43
711.95:505:43
811.95:505:43
911.95:495:43
1011.95:485:43
1111.95:485:43
1211.95:475:42
1311.95:465:42
1411.95:465:42
1511.95:455:42
1612.05:455:42
1712.05:445:42
1812.05:435:42
1912.05:435:42
2012.05:425:41
2112.05:425:41
2212.05:415:41
2312.05:405:41
2412.05:405:41
2512.05:395:41
2612.05:395:41
2712.05:385:41
2812.05:375:40
2912.15:375:40
3012.15:365:40

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.74 kWh/m².

For context, solar energy here swings from a low near 4.81 kWh/m² to a high of 6.8 kWh/m² in October across the year — September's 6.74 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
16.5Intense
26.5Intense
36.5Intense
46.5Intense
56.6Intense
66.6Intense
76.6Intense
86.6Intense
96.6Intense
106.7Intense
116.7Intense
126.7Intense
136.7Intense
146.7Intense
156.8Intense
166.8Intense
176.8Intense
186.8Intense
196.8Intense
206.8Intense
216.8Intense
226.9Intense
236.9Intense
246.9Intense
256.9Intense
266.9Intense
276.9Intense
286.9Intense
296.9Intense
306.9Intense
Planning a trip in September

Hazard calendar for São João do Piauí

In seasonPeak

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

São João do Piauí's rainy season runs December–April, 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 São João do Piauí?

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

2.8
Sightseeing
10th-best month of the year
6.5
Beach & pool
5th-best month of the year

September is a weaker month for outdoor sightseeing in São João do Piauí. The water and warmth also suit a beach or pool day.

What to pack for São João do Piauí in September

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

In September, São João do Piauí sees daytime highs around 36°C and nights near 24°C. Pack light clothes and sun protection.

light clothessun protection

UV index in São João do Piauí 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 São João do Piauí peaks around March 11 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 14 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 11UV 15Jul 14UV 10
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar15Extreme
Apr13Extreme
May10Extreme
Jun10Very high
Jul10Very high
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec12Extreme
Location & terrain

Where is São João do Piauí?

São João do Piauí sits at 8.4°S, 42.2°W, 219 m above sea level, in Brazil. The nearest listed city is Canto do Buriti, 82 km away.

Topography around São João do Piauí

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

Within 3 km, the terrain around São João do Piauí has only modest variations in elevation — a maximum elevation change of 90 m around an average of 227 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 204 m; within 80 km, significant variations in elevation — a maximum elevation change of 518 m.

The land around São João do Piauí is covered by shrubs (49%) and grassland (28%) within 3 km, shrubs (88%) within 16 km, and shrubs (94%) within 80 km.

3 km
90 m
16 km
204 m
80 km
518 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Canto do Buriti 82 km · São Raimundo Nonato 88 km · Paulistana 123 km · Afrânio 138 km · Remanso 142 km · Oeiras 149 km · Campo Alegre de Lourdes 154 km · Sento Sé 159 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 João do Piauí (-8.3581°, -42.2467°, elevation 219 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).