Luján weather in September

In September, Luján sees average daytime highs of 19°C and overnight lows near 9°C, with 71 mm of rain across 6.5 wet days and about 11.8 hours of daylight. It is the 8th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 18°C in the first days to 20°C by the end. The sky is clear or mostly clear about 40% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 12 min at the start of September to 12 h 18 min by month's end. Set against the rest of the year, September is Luján's 8th-clearest and 1st-windiest month. For the whole year in context, see Luján's year-round climate.

Daytime high
19°
8th warmest
Overnight low
4th coldest
Rainfall
71 mm
6.5 wet days
Daylight
11 h 48 min
6:57 AM – 6:44 PM
Cloud cover
53%
8th clearest
Wind
14 km/h
1st windiest
Solar energy
4.53 kWh/m²
Travel score
6.7
out of 10

Luján is city in Buenos Aires Province, Argentina.

Founded
1738

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 18°C in the first days to 20°C by the end.

A typical September day in Luján reaches about 19°C in the afternoon and slips back to 9°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 24°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)
1188
2188
3188
4188
5188
6188
7188
8198
9198
10198
11198
12198
13198
14199
15199
16199
17199
18199
19199
20199
21209
22209
23209
24209
25209
26209
272010
282010
292010
302010

Luján 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
Jan29° / 18°917.814.15.8
Feb28° / 18°1018.313.36.3
Mar26° / 16°927.312.37.3
Apr23° / 12°968.311.27.2
May19° / 665.910.26.6
Jun16° / 545.89.75.3
Jul15° / 585.89.95.0
Aug17° / 615.510.76.2
Sep19° / 716.511.86.7
Oct22° / 12°1199.312.96.9
Nov25° / 14°948.213.87.2
Dec28° / 17°938.814.36.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% 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 47%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15248
25248
35248
45347
55446
65446
75446
85545
95545
105545
115644
125545
135545
145545
155545
165545
175545
185347
195347
205248
215248
225248
235149
245050
255050
265050
275050
284951
294951
304951

Chance of precipitation in September

Any precipitation

Luján gets around 71 mm of rain over 6.5 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 22% and peaks near 26% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
122
223
323
423
523
622
722
822
922
1021
1121
1221
1320
1420
1520
1620
1720
1820
1920
2020
2121
2221
2322
2422
2523
2624
2724
2825
2925
3026

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 85% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1851140
2851140
3851140
4851140
5861040
6861040
7861040
8861040
9861040
1087940
1187940
1287940
1385951
1485951
1586941
1686941
1786941
1886941
1986941
2086941
21851041
22851041
23841141
24831241
25821341
26821341
27811441
28801541
29801550
30791650

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 12 min at the start of September to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over September. Sunrise moves from 7:19 AM to 6:37 AM, and sunset from 6:33 PM to 6:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.27:196:33
211.37:186:34
311.37:166:35
411.37:156:36
511.47:136:36
611.47:126:37
711.57:106:38
811.57:096:39
911.57:076:39
1011.67:066:40
1111.67:056:41
1211.67:036:41
1311.77:026:42
1411.77:006:43
1511.86:596:44
1611.86:576:44
1711.86:566:45
1811.96:546:46
1911.96:536:47
2011.96:516:47
2112.06:506:48
2212.06:486:49
2312.06:476:50
2412.16:456:50
2512.16:446:51
2612.26:426:52
2712.26:416:53
2812.26:396:53
2912.36:386:54
3012.36:376:55

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.53 kWh/m².

For context, solar energy here swings from a low near 2.26 kWh/m² to a high of 7.44 kWh/m² in December across the year — September's 4.53 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
13.9Moderate
23.9Moderate
34.0Moderate
44.0Bright
54.1Bright
64.1Bright
74.2Bright
84.2Bright
94.3Bright
104.3Bright
114.4Bright
124.4Bright
134.5Bright
144.5Bright
154.6Bright
164.6Bright
174.7Bright
184.7Bright
194.7Bright
204.8Bright
214.8Bright
224.8Bright
234.8Bright
244.8Bright
254.9Bright
264.9Bright
274.9Bright
284.9Bright
295.0Bright
305.0Bright
Planning a trip in September

Is September a good time to visit Luján?

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

6.7
Sightseeing
5th-best month of the year
2.9
Beach & pool
8th-best month of the year

September is a reasonable time to visit Luján for sightseeing.

What to pack for Luján in September

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

In September, Luján sees daytime highs around 19°C and nights near 9°C. Worth packing: sun protection. About 7 days see rain.

sun protection

Sea temperature near Luján in September

The nearest coast averages about 15°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 68 km away) is warmest in January at about 25°C and coldest in July near 13°C.

It's comfortable for a long swim from Nov 9 to Apr 20 — about 5.4 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swimcomfortable to swim
Sea temperature (°C)Comfort
Jan25Warm
Feb25Warm
Mar23Refreshing
Apr21Refreshing
May17Cool
Jun14Bracing
Jul13Bracing
Aug13Bracing
Sep15Cool
Oct18Cool
Nov21Refreshing
Dec23Refreshing

UV index in Luján in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Luján peaks around January 14 at about 13 (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 — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighVery highExtremeJan 14UV 13Jun 19UV 3
UV index (midday)Level
Jan13Extreme
Feb11Extreme
Mar9Very high
Apr6High
May4Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct8Very high
Nov11Extreme
Dec12Extreme

Air quality in Luján 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 Luján is worst in August — around 20 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (November, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodAug 1619 µg/m³Nov 2310 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb11Good
Mar12Moderate
Apr11Good
May14Moderate
Jun16Moderate
Jul16Moderate
Aug20Moderate
Sep15Moderate
Oct13Moderate
Nov10Good
Dec11Good
Location & terrain

Where is Luján?

Luján sits at 34.6°S, 59.1°W, 17 m above sea level, in Argentina. The nearest listed city is Pilar, 22 km away.

Topography around Luján

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

Within 3 km, the terrain around Luján has only modest variations in elevation — a maximum elevation change of 25 m around an average of 24 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 62 m; within 80 km, only modest variations in elevation — a maximum elevation change of 83 m.

The land around Luján is covered by artificial surfaces (49%), trees (26%) and grassland (20%) within 3 km, cropland (52%) and grassland (28%) within 16 km, and cropland (42%) and grassland (27%) within 80 km.

3 km
25 m
16 km
62 m
80 km
83 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Pilar 22 km · Mercedes 30 km · Moreno 31 km · José C. Paz 32 km · Tortuguitas 35 km · San Miguel 37 km · Merlo 37 km · Muñiz 37 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 Luján (-34.5664°, -59.1148°, elevation 17 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. 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).