Rosario de Lerma weather in September

In September, Rosario de Lerma sees average daytime highs of 20°C and overnight lows near 8°C, with 39 mm of precipitation across 7.6 wet days and about 11.8 hours of daylight. It is the 7th-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 20°C through the month. The sky is clear or mostly clear about 54% 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 Rosario de Lerma's 3rd-clearest and 1st-windiest month. For the whole year in context, see Rosario de Lerma's year-round climate.

Daytime high
20°
7th warmest
Overnight low
5th coldest
Precipitation
39 mm
7.6 wet days
Daylight
11 h 54 min
7:21 AM – 7:12 PM
Cloud cover
42%
3rd clearest
Wind
5 km/h
1st windiest
Solar energy
5.69 kWh/m²
Travel score
7.0
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 20°C through the month.

A typical September day in Rosario de Lerma reaches about 20°C in the afternoon and slips back to 8°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 27°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)
1207
2207
3207
4207
5207
6207
7207
8208
9208
10208
11208
12208
13208
14208
15208
16208
17218
18219
19219
20219
21219
22219
23219
24219
25219
262110
272110
282110
292110
302110

Rosario de Lerma weather by month

How September compares with the rest of the year at a glance. September is the 7th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan24° / 16°21624.3013.44.6
Feb23° / 16°19522.7012.94.4
Mar22° / 15°20223.8012.24.4
Apr20° / 12°12919.50.111.44.7
May17° / 7413.60.210.85.1
Jun16° / 368.20.410.55.5
Jul16° / 286.70.710.65.8
Aug18° / 275.80.311.17.0
Sep20° / 397.60.111.87.0
Oct22° / 12°91140.112.66.2
Nov23° / 14°12616.5013.25.7
Dec24° / 15°18121.2013.55.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% 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 33%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17228
27228
37228
47129
57030
66931
76931
86931
96832
106832
116832
126832
136832
146832
156832
166832
176733
186733
196733
206733
216634
226634
236535
246535
256436
266238
276238
286139
296040
306040

Chance of precipitation in September

Any precipitation

Rosario de Lerma gets around 39 mm of rain and snow over 7.6 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 26% and peaks near 36% on the wettest days, and about 0 day brings snow. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
119
220
321
421
522
622
723
823
923
1023
1123
1223
1323
1423
1524
1624
1724
1825
1926
2026
2127
2228
2329
2430
2531
2632
2734
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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
61000
71000
81000
91000
101000
111000
121000
13991
14991
15991
16991
17991
18982
19982
20982
21982
22973
23973
24973
25964
26964
27955
28955
29946
30946

Wind in September

Winds average 5 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

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 7:37 AM to 7:05 AM, and sunset from 7:07 PM to 7:18 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:377:07
211.57:367:07
311.57:357:07
411.67:347:08
511.67:337:08
611.67:327:09
711.67:317:09
811.77:307:09
911.77:297:10
1011.77:287:10
1111.77:277:10
1211.87:257:11
1311.87:247:11
1411.87:237:12
1511.87:227:12
1611.97:217:12
1711.97:207:13
1811.97:197:13
1911.97:187:13
2012.07:167:14
2112.07:157:14
2212.07:147:15
2312.07:137:15
2412.17:127:15
2512.17:117:16
2612.17:107:16
2712.17:097:17
2812.27:087:17
2912.27:077:17
3012.27:057:18

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.69 kWh/m².

For context, solar energy here swings from a low near 3.59 kWh/m² to a high of 6.02 kWh/m² in November across the year — September's 5.69 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.6Bright
95.6Bright
105.6Bright
115.6Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.7Bright
175.8Bright
185.8Bright
195.8Bright
205.8Bright
215.8Bright
225.8Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.9Bright
Planning a trip in September

Hazard calendar for Rosario de Lerma

In seasonPeak

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

Rosario de Lerma's rainy season runs November–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 Rosario de Lerma?

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

7.0
Sightseeing
1st-best month of the year
3.9
Beach & pool
5th-best month of the year

September is one of the better times to visit Rosario de Lerma for general sightseeing.

What to pack for Rosario de Lerma in September

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

In September, Rosario de Lerma sees daytime highs around 20°C and nights near 8°C. Worth packing: sun protection. About 8 days see rain.

sun protection

UV index in Rosario de Lerma in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Rosario de Lerma peaks around January 16 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 10 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 16UV 16Jul 10UV 6
UV index (midday)Level
Jan16Extreme
Feb16Extreme
Mar14Extreme
Apr9Very high
May7Very high
Jun6High
Jul6High
Aug8Very high
Sep10Extreme
Oct13Extreme
Nov15Extreme
Dec16Extreme
Location & terrain

Where is Rosario de Lerma?

Rosario de Lerma sits at 25.0°S, 65.6°W, 1,421 m above sea level, in Argentina. The nearest listed city is San José de los Cerrillos, 14 km away.

Topography around Rosario de Lerma

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

Within 3 km, the terrain around Rosario de Lerma has only modest variations in elevation — a maximum elevation change of 103 m around an average of 1,318 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,912 m; within 80 km, extreme variations in elevation — a maximum elevation change of 5,593 m.

The land around Rosario de Lerma is covered by cropland (66%) within 3 km, cropland (45%) and trees (38%) within 16 km, and trees (37%), grassland (23%) and bare terrain (23%) within 80 km.

3 km
103 m
16 km
1,912 m
80 km
5,593 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
September weather nearby: San José de los Cerrillos 14 km · Salta 26 km · San Lorenzo 29 km · General Güemes 64 km · San José de Metán 83 km · Palpalá 89 km · San Salvador de Jujuy 93 km · Rosario de la Frontera 109 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 Rosario de Lerma (-24.9858°, -65.5784°, elevation 1,421 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).