Formosa weather in September

In September, Formosa sees average daytime highs of 26°C and overnight lows near 16°C, with 111 mm of rain across 8.6 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 52% 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 Formosa's 2nd-clearest and 2nd-windiest month. For the whole year in context, see Formosa's year-round climate.

Daytime high
26°
8th warmest
Overnight low
16°
5th coldest
Rainfall
111 mm
8.6 wet days
Daylight
11 h 48 min
6:52 AM – 6:42 PM
Cloud cover
43%
2nd clearest
Wind
15 km/h
2nd windiest
Solar energy
4.81 kWh/m²
Travel score
7.1
out of 10

Formosa is city in Argentina.

Density
2,963/km²
people per km²
Founded
1879

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 26°C through the month.

A typical September day in Formosa reaches about 26°C in the afternoon and slips back to 16°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 34°C. Set against its neighbours, September runs about 2°C warmer than August and about 2°C cooler than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12615
22615
32615
42615
52615
62615
72615
82615
92615
102615
112615
122615
132615
142615
152615
162615
172615
182716
192716
202716
212716
222716
232716
242716
252716
262716
272716
282717
292717
302717

How September really feels in Formosa

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.

Formosa weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 23°11911.113.53.5
Feb32° / 23°13711.512.93.8
Mar31° / 21°12810.912.24.7
Apr28° / 18°1539.511.46.3
May24° / 15°1288.410.77.2
Jun22° / 14°998.410.47.0
Jul22° / 12°787.510.57.3
Aug24° / 14°646.611.17.8
Sep26° / 16°1118.611.87.1
Oct29° / 18°18411.512.65.7
Nov30° / 20°18210.613.35.0
Dec32° / 22°16211.413.64.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% 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 36%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17030
27030
37030
46931
56931
66832
76832
86733
96634
106634
116634
126634
136634
146535
156436
166436
176436
186337
196337
206238
216238
226238
236139
246139
256040
265941
275842
285743
295743
305743

Chance of precipitation in September

Any precipitation

Formosa gets around 111 mm of rain over 8.6 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 29% and peaks near 35% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
123
223
323
423
523
624
724
824
925
1025
1126
1226
1327
1427
1528
1629
1729
1830
1930
2031
2132
2232
2333
2433
2534
2634
2734
2834
2935
3035

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 39% of days. Sticky, muggy-or-worse air turns up on roughly 15% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
146232290
245232290
3452322100
4452322100
5442322100
6442322100
7442322100
8442322100
9432322110
10432322110
11432322110
12422323111
13422323111
14422323121
15412323121
16412323121
17412323121
18402322132
19402322132
20392222142
21382223152
22372223152
23362223162
24352224173
25342124183
26322124193
27312125203
28302125213
29292125223
30272125234

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 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light 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 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 7:09 AM to 6:35 AM, and sunset from 6:36 PM to 6:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:096:36
211.57:086:37
311.57:066:37
411.57:056:37
511.67:046:38
611.67:036:38
711.67:026:39
811.67:016:39
911.77:006:40
1011.76:596:40
1111.76:576:40
1211.76:566:41
1311.86:556:41
1411.86:546:42
1511.86:536:42
1611.86:526:42
1711.96:506:43
1811.96:496:43
1911.96:486:44
2012.06:476:44
2112.06:466:45
2212.06:456:45
2312.06:436:45
2412.16:426:46
2512.16:416:46
2612.16:406:47
2712.16:396:47
2812.26:386:48
2912.26:376:48
3012.26:356:49

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.81 kWh/m².

For context, solar energy here swings from a low near 2.67 kWh/m² to a high of 6.75 kWh/m² in December across the year — September's 4.81 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.6Bright
44.6Bright
54.6Bright
64.6Bright
74.7Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.8Bright
134.8Bright
144.8Bright
154.8Bright
164.8Bright
174.9Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
225.0Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.1Bright
295.1Bright
305.1Bright
Planning a trip in September

Is September a good time to visit Formosa?

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

7.1
Sightseeing
4th-best month of the year
6.9
Beach & pool
2nd-best month of the year

September is one of the better times to visit Formosa for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Formosa in September

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

In September, Formosa sees daytime highs around 26°C and nights near 16°C. Worth packing: light clothes, rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Formosa in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Formosa peaks around January 18 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighModerateVery highExtremeJan 18UV 14Jun 21UV 4
UV index (midday)Level
Jan15Extreme
Feb14Extreme
Mar11Extreme
Apr8Very high
May6High
Jun4Moderate
Jul5Moderate
Aug5Moderate
Sep8Very high
Oct7Very high
Nov12Extreme
Dec13Extreme

Air quality in Formosa 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 Formosa is worst in September — around 23 µg/m³ PM2.5 (moderate), about 2.9× the cleanest month (May, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodSep 1222 µg/m³May 198 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb13Moderate
Mar13Moderate
Apr10Good
May8Good
Jun9Good
Jul12Good
Aug21Moderate
Sep23Moderate
Oct15Moderate
Nov10Good
Dec9Good
Location & terrain

Where is Formosa?

Formosa sits at 26.2°S, 58.2°W, 67 m above sea level, in Argentina. The nearest listed city is Pilar, 76 km away.

Topography around Formosa

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

Within 3 km, the terrain around Formosa has only modest variations in elevation — a maximum elevation change of 17 m around an average of 58 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 23 m; within 80 km, only modest variations in elevation — a maximum elevation change of 182 m.

The land around Formosa is covered by artificial surfaces (50%) and trees (29%) within 3 km, trees (44%) and grassland (39%) within 16 km, and grassland (49%) and trees (36%) within 80 km.

3 km
17 m
16 km
23 m
80 km
182 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Pilar 76 km · San Antonio 106 km · Pirané 106 km · Villa Elisa 108 km · Nemby 109 km · Lambaré 109 km · Itá 111 km · Asuncion 113 km

Argentina travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / I
220 V · 50 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$14,898
2025
Happiness
6.4 / 10
World Happiness, 2025
Homicide rate
4.5
per 100k, 2023
Road deaths
14.1
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
High
EF EPI 575
Religion
Roman Catholic 63%none 19%Evangelical 15%Jehovah's Witness and Church of Jesus Christ 1%

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 Formosa (-26.1849°, -58.1731°, elevation 67 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).