Tres Arroyos weather in September

In September, Tres Arroyos sees average daytime highs of 17°C and overnight lows near 6°C, with 51 mm of rain across 6.9 wet days and about 11.7 hours of daylight. It is the 8th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 16°C in the first days to 18°C by the end. The sky is clear or mostly clear about 36% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 06 min at the start of September to 12 h 24 min by month's end. Set against the rest of the year, September is Tres Arroyos's 9th-clearest and 7th-windiest month. For the whole year in context, see Tres Arroyos's year-round climate.

Daytime high
17°
8th warmest
Overnight low
4th coldest
Rainfall
51 mm
6.9 wet days
Daylight
11 h 48 min
7:03 AM – 6:48 PM
Cloud cover
57%
9th clearest
Wind
16 km/h
7th windiest
Solar energy
4.34 kWh/m²
Travel score
5.8
out of 10

Tres Arroyos is city in Buenos Aires Province, Argentina.

Density
3,139/km²
people per km²
Founded
1884

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 16°C in the first days to 18°C by the end.

A typical September day in Tres Arroyos reaches about 17°C in the afternoon and slips back to 6°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 22°C. Set against its neighbours, September runs about 2°C warmer than August and about 3°C cooler than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
1165
2165
3165
4165
5166
6166
7166
8166
9166
10166
11166
12176
13176
14176
15176
16176
17176
18176
19176
20176
21176
22176
23176
24187
25187
26187
27187
28187
29187
30187

How September really feels in Tres Arroyos

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.

Tres Arroyos weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 15°749.714.46.1
Feb27° / 15°758.313.56.9
Mar25° / 13°768.212.37.4
Apr21° / 10°647.2116.9
May17° / 466.29.95.7
Jun13° / 335.29.44.2
Jul13° / 386.19.63.8
Aug15° / 475.810.54.9
Sep17° / 516.911.75.8
Oct20° / 789.4136.4
Nov23° / 11°839.314.17.1
Dec27° / 14°788.814.66.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14951
24951
34951
44852
54852
64852
74951
84951
95050
105050
115050
125149
135149
145149
155248
165149
175149
185149
195149
205050
215050
225050
234951
244852
254852
264753
274654
284654
294654
304654

Chance of precipitation in September

Any precipitation

Tres Arroyos gets around 51 mm of rain over 6.9 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 23% and peaks near 27% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
120
220
321
421
521
622
722
822
922
1023
1123
1223
1323
1423
1523
1623
1723
1823
1923
2023
2123
2223
2324
2424
2525
2625
2726
2826
2927
3027

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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
19721
29721
39721
49721
59811
69811
79811
89811
99811
109811
119811
129811
139811
149811
159811
169811
179811
189811
199910
209910
219910
229910
239910
249820
259820
269820
279820
289820
299730
309730

Wind in September

Winds average 16 km/h in September.

Across September, daily wind ranges from about 16 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
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 06 min at the start of September to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 78 minutes over September. Sunrise moves from 7:27 AM to 6:40 AM, and sunset from 6:35 PM to 7:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.17:276:35
211.27:256:36
311.27:246:36
411.37:226:37
511.37:216:38
611.37:196:39
711.47:176:40
811.47:166:41
911.57:146:42
1011.57:136:43
1111.57:116:44
1211.67:096:44
1311.67:086:45
1411.77:066:46
1511.77:046:47
1611.87:036:48
1711.87:016:49
1811.86:596:50
1911.96:586:51
2011.96:566:52
2112.06:556:53
2212.06:536:54
2312.16:516:54
2412.16:506:55
2512.16:486:56
2612.26:466:57
2712.26:456:58
2812.36:436:59
2912.36:417:00
3012.46:407:01

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.34 kWh/m².

For context, solar energy here swings from a low near 1.95 kWh/m² to a high of 7.77 kWh/m² in December across the year — September's 4.34 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
13.6Moderate
23.7Moderate
33.7Moderate
43.8Moderate
53.8Moderate
63.9Moderate
73.9Moderate
84.0Moderate
94.0Bright
104.1Bright
114.1Bright
124.2Bright
134.3Bright
144.3Bright
154.3Bright
164.4Bright
174.4Bright
184.5Bright
194.5Bright
204.6Bright
214.6Bright
224.6Bright
234.7Bright
244.7Bright
254.7Bright
264.7Bright
274.8Bright
284.8Bright
294.8Bright
304.9Bright
Planning a trip in September

Is September a good time to visit Tres Arroyos?

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

5.8
Sightseeing
8th-best month of the year
1.3
Beach & pool
8th-best month of the year

September is a reasonable time to visit Tres Arroyos for sightseeing.

What to pack for Tres Arroyos in September

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

In September, Tres Arroyos sees daytime highs around 17°C and nights near 6°C. Worth packing: a warm layer. About 7 days see rain.

a warm layer

Sea temperature near Tres Arroyos in September

The nearest coast averages about 11°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 56 km away) is warmest in February at about 21°C and coldest in August near 10°C.

It's comfortable for a long swim from Jan 8 to Mar 21 — about 2.4 months when the water holds above 20°C.

10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb21Refreshing
Mar20Refreshing
Apr18Cool
May15Cool
Jun12Bracing
Jul10Bracing
Aug10Bracing
Sep11Bracing
Oct13Bracing
Nov16Cool
Dec18Cool

UV index in Tres Arroyos in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Tres Arroyos peaks around December 20 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateModerateVery highExtremeDec 20UV 12Jun 21UV 2
UV index (midday)Level
Jan12Extreme
Feb12Extreme
Mar8Very high
Apr6High
May3Moderate
Jun2Low
Jul2Moderate
Aug3Moderate
Sep5Moderate
Oct7Very high
Nov10Very high
Dec13Extreme
Location & terrain

Where is Tres Arroyos?

Tres Arroyos sits at 38.4°S, 60.3°W, 100 m above sea level, in Argentina. The nearest listed city is Benito Juárez, 89 km away.

Topography around Tres Arroyos

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

Within 3 km, the terrain around Tres Arroyos has only modest variations in elevation — a maximum elevation change of 21 m around an average of 109 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 93 m; within 80 km, significant variations in elevation — a maximum elevation change of 268 m.

The land around Tres Arroyos is covered by artificial surfaces (43%) and grassland (41%) within 3 km, cropland (81%) within 16 km, and cropland (61%) and grassland (28%) within 80 km.

3 km
21 m
16 km
93 m
80 km
268 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Benito Juárez 89 km · Coronel Pringles 104 km · Necochea 135 km · Tandil 154 km · Olavarría 165 km · Punta Alta 166 km · Bahía Blanca 177 km · Coronel Suárez 178 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 Tres Arroyos (-38.3769°, -60.2756°, elevation 100 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).