San Luis weather in September

In September, San Luis sees average daytime highs of 21°C and overnight lows near 9°C, with 30 mm of precipitation across 4.6 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 20°C in the first days to 22°C by the end. The sky is clear or mostly clear about 59% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 18 min at the start of September to 12 h 18 min by month's end. Set against the rest of the year, September is San Luis's 3rd-clearest and 3rd-windiest month. For the whole year in context, see San Luis's year-round climate.

Daytime high: 21°; 8th warmest
Overnight low: 9°; 5th coldest
Precipitation: 30 mm; 4.6 wet days
Daylight: 11 h 48 min; 7:26 AM – 7:14 PM
Cloud cover: 36%; 3rd clearest
Wind: 12 km/h; 3rd windiest
Solar energy: 5.19 kWh/m²
Travel score: 7.6; out of 10

San Luis is capital city of the San Luis Province in the Cuyo region of Argentina.

Founded: 1594

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

← August San Luis year-round climate October →Best places to visit in September

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 20°C in the first days to 22°C by the end.

A typical September day in San Luis reaches about 21°C in the afternoon and slips back to 9°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 28°C. Set against its neighbours, September runs about 3°C warmer than August and about 3°C cooler than October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	20	20	20	20	20	20	20	20	20	20	20	20	21	21	21	21	21	21	21	21	21	21	22	22	22	22	22	22	22	22
Avg low (°C)	7	8	8	8	8	8	8	8	8	8	8	8	8	8	9	9	9	9	9	9	9	9	9	9	10	10	10	10	10	10

	Avg high (°C)	Avg low (°C)
1	20	7
2	20	8
3	20	8
4	20	8
5	20	8
6	20	8
7	20	8
8	20	8
9	20	8
10	20	8
11	20	8
12	20	8
13	21	8
14	21	8
15	21	9
16	21	9
17	21	9
18	21	9
19	21	9
20	21	9
21	21	9
22	21	9
23	22	9
24	22	9
25	22	10
26	22	10
27	22	10
28	22	10
29	22	10
30	22	10

San Luis 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.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	29° / 18°	107	13.3	14	5.3
Feb	28° / 17°	81	10.9	13.2	6.3
Mar	26° / 15°	80	10.1	12.3	7.1
Apr	22° / 11°	53	7	11.2	7.4
May	18° / 8°	25	4.2	10.3	6.8
Jun	16° / 5°	8	1.9	9.8	6.3
Jul	16° / 4°	9	2.1	10	6.1
Aug	18° / 6°	15	2.6	10.8	7.4
Sep	21° / 9°	30	4.6	11.8	7.6
Oct	24° / 12°	66	8.7	12.8	7.5
Nov	26° / 14°	89	11.7	13.7	6.7
Dec	28° / 17°	102	13.1	14.2	5.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 28%. Skies tend to cloud over as the month goes on.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	74	74	74	73	73	73	73	74	74	74	73	74	74	74	74	74	74	74	73	73	73	72	71	71	70	69	68	68	68	67
Cloudier (%)	26	26	26	27	27	27	27	26	26	26	27	26	26	26	26	26	26	26	27	27	27	28	29	29	30	31	32	32	32	33

	Clearer (%)	Cloudier (%)
1	74	26
2	74	26
3	74	26
4	73	27
5	73	27
6	73	27
7	73	27
8	74	26
9	74	26
10	74	26
11	73	27
12	74	26
13	74	26
14	74	26
15	74	26
16	74	26
17	74	26
18	74	26
19	73	27
20	73	27
21	73	27
22	72	28
23	71	29
24	71	29
25	70	30
26	69	31
27	68	32
28	68	32
29	68	32
30	67	33

Chance of precipitation in September

Any precipitation

San Luis gets around 30 mm of rain and snow over 4.6 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 16% and peaks near 22% on the wettest days, and about 0 day brings snow. The odds climb toward the end of the month.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	11	11	11	11	12	12	12	13	13	13	13	14	14	14	15	15	15	16	16	17	17	18	18	19	20	20	21	21	21	22

	Rain chance (%)
1	11
2	11
3	11
4	11
5	12
6	12
7	12
8	13
9	13
10	13
11	13
12	14
13	14
14	14
15	15
16	15
17	15
18	16
19	16
20	17
21	17
22	18
23	18
24	19
25	20
26	20
27	21
28	21
29	21
30	22

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	99	99	99	99	99	99	99	99	99	99	99	99	99	99	99	98
Comfortable (%)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	2

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	99	1
16	99	1
17	99	1
18	99	1
19	99	1
20	99	1
21	99	1
22	99	1
23	99	1
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	98	2

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12	13	13	13	13	13	13	13	13	13	13	13
Feels	calm	calm	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

	Wind speed (km/h)	Feels
1	12	calm
2	12	calm
3	12	light breeze
4	12	light breeze
5	12	light breeze
6	12	light breeze
7	12	light breeze
8	12	light breeze
9	12	light breeze
10	12	light breeze
11	12	light breeze
12	12	light breeze
13	12	light breeze
14	12	light breeze
15	12	light breeze
16	12	light breeze
17	12	light breeze
18	12	light breeze
19	12	light breeze
20	13	light breeze
21	13	light breeze
22	13	light breeze
23	13	light breeze
24	13	light breeze
25	13	light breeze
26	13	light breeze
27	13	light breeze
28	13	light breeze
29	13	light breeze
30	13	light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 18 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 60 minutes over September. Sunrise moves from 7:47 AM to 7:06 AM, and sunset from 7:03 PM to 7:23 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	11.3	11.3	11.3	11.4	11.4	11.4	11.5	11.5	11.6	11.6	11.6	11.7	11.7	11.7	11.8	11.8	11.8	11.9	11.9	11.9	12.0	12.0	12.0	12.1	12.1	12.2	12.2	12.2	12.3	12.3
Sunrise (AM)	7:47	7:45	7:44	7:43	7:41	7:40	7:38	7:37	7:36	7:34	7:33	7:31	7:30	7:29	7:27	7:26	7:24	7:23	7:21	7:20	7:19	7:17	7:16	7:14	7:13	7:11	7:10	7:09	7:07	7:06
Sunset (PM)	7:03	7:04	7:05	7:05	7:06	7:07	7:07	7:08	7:09	7:09	7:10	7:11	7:11	7:12	7:13	7:14	7:14	7:15	7:16	7:16	7:17	7:18	7:18	7:19	7:20	7:20	7:21	7:22	7:23	7:23

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.3	7:47	7:03
2	11.3	7:45	7:04
3	11.3	7:44	7:05
4	11.4	7:43	7:05
5	11.4	7:41	7:06
6	11.4	7:40	7:07
7	11.5	7:38	7:07
8	11.5	7:37	7:08
9	11.6	7:36	7:09
10	11.6	7:34	7:09
11	11.6	7:33	7:10
12	11.7	7:31	7:11
13	11.7	7:30	7:11
14	11.7	7:29	7:12
15	11.8	7:27	7:13
16	11.8	7:26	7:14
17	11.8	7:24	7:14
18	11.9	7:23	7:15
19	11.9	7:21	7:16
20	11.9	7:20	7:16
21	12.0	7:19	7:17
22	12.0	7:17	7:18
23	12.0	7:16	7:18
24	12.1	7:14	7:19
25	12.1	7:13	7:20
26	12.2	7:11	7:20
27	12.2	7:10	7:21
28	12.2	7:09	7:22
29	12.3	7:07	7:23
30	12.3	7:06	7:23

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.19 kWh/m².

For context, solar energy here swings from a low near 2.78 kWh/m² to a high of 7.59 kWh/m² in December across the year — September's 5.19 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	4.6	4.7	4.7	4.7	4.8	4.8	4.8	4.9	4.9	5.0	5.0	5.1	5.1	5.2	5.2	5.3	5.3	5.3	5.4	5.4	5.4	5.5	5.5	5.5	5.5	5.5	5.6	5.6	5.6	5.6
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	4.6	Bright
2	4.7	Bright
3	4.7	Bright
4	4.7	Bright
5	4.8	Bright
6	4.8	Bright
7	4.8	Bright
8	4.9	Bright
9	4.9	Bright
10	5.0	Bright
11	5.0	Bright
12	5.1	Bright
13	5.1	Bright
14	5.2	Bright
15	5.2	Bright
16	5.3	Bright
17	5.3	Bright
18	5.3	Bright
19	5.4	Bright
20	5.4	Bright
21	5.4	Bright
22	5.5	Bright
23	5.5	Bright
24	5.5	Bright
25	5.5	Bright
26	5.5	Bright
27	5.6	Bright
28	5.6	Bright
29	5.6	Bright
30	5.6	Bright

Planning a trip in September

Hazard calendar for San Luis

In seasonPeak

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

San Luis's rainy season runs October–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 San Luis?

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

7.6

Sightseeing

1st-best month of the year

4.5

Beach & pool

8th-best month of the year

September is one of the better times to visit San Luis for general sightseeing.

What to pack for San Luis in September

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

In September, San Luis sees daytime highs around 21°C and nights near 9°C. Worth packing: sun protection. About 5 days see rain.

sun protection

UV index in San Luis 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 San Luis peaks around January 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 3 (moderate).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	14	13	10	6	4	3	3	4	6	10	12	13
Level	Extreme	Extreme	Extreme	High	Moderate	Moderate	Moderate	Moderate	High	Very high	Extreme	Extreme

	UV index (midday)	Level
Jan	14	Extreme
Feb	13	Extreme
Mar	10	Extreme
Apr	6	High
May	4	Moderate
Jun	3	Moderate
Jul	3	Moderate
Aug	4	Moderate
Sep	6	High
Oct	10	Very high
Nov	12	Extreme
Dec	13	Extreme

Location & terrain

Where is San Luis?

San Luis sits at 33.3°S, 66.3°W, 729 m above sea level, in Argentina. The nearest listed city is Villa Mercedes, 91 km away.

Topography around San Luis

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

Within 3 km, the terrain around San Luis has only modest variations in elevation — a maximum elevation change of 121 m around an average of 743 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,416 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,820 m.

The land around San Luis is covered by artificial surfaces (72%) within 3 km, shrubs (50%) and grassland (24%) within 16 km, and shrubs (59%) and grassland (22%) within 80 km.

3 km

121 m

artificial surfaces 72%

16 km

1,416 m

shrubs 50%

80 km

1,820 m

shrubs 59%

treesshrubsgrasslandcroplandartificial surfacesbare terrain

← August San Luis year-round climate October →Best places to visit in September

September weather nearby: Villa Mercedes 91 km · Villa Dolores 184 km · Río Cuarto 184 km · Rivadavia 199 km · San Martín 201 km · Embalse 217 km · Rodeo del Medio 222 km · General Alvear 226 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

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 San Luis (-33.2914°, -66.3247°, elevation 729 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).

	Avg high (°C)	Avg low (°C)
1	20	7
2	20	8
3	20	8
4	20	8
5	20	8
6	20	8
7	20	8
8	20	8
9	20	8
10	20	8
11	20	8
12	20	8
13	21	8
14	21	8
15	21	9
16	21	9
17	21	9
18	21	9
19	21	9
20	21	9
21	21	9
22	21	9
23	22	9
24	22	9
25	22	10
26	22	10
27	22	10
28	22	10
29	22	10
30	22	10

	Clearer (%)	Cloudier (%)
1	74	26
2	74	26
3	74	26
4	73	27
5	73	27
6	73	27
7	73	27
8	74	26
9	74	26
10	74	26
11	73	27
12	74	26
13	74	26
14	74	26
15	74	26
16	74	26
17	74	26
18	74	26
19	73	27
20	73	27
21	73	27
22	72	28
23	71	29
24	71	29
25	70	30
26	69	31
27	68	32
28	68	32
29	68	32
30	67	33

	Rain chance (%)
1	11
2	11
3	11
4	11
5	12
6	12
7	12
8	13
9	13
10	13
11	13
12	14
13	14
14	14
15	15
16	15
17	15
18	16
19	16
20	17
21	17
22	18
23	18
24	19
25	20
26	20
27	21
28	21
29	21
30	22

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	99	1
16	99	1
17	99	1
18	99	1
19	99	1
20	99	1
21	99	1
22	99	1
23	99	1
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	98	2

	Avg high (°C)	Avg low (°C)
1	20	7
2	20	8
3	20	8
4	20	8
5	20	8
6	20	8
7	20	8
8	20	8
9	20	8
10	20	8
11	20	8
12	20	8
13	21	8
14	21	8
15	21	9
16	21	9
17	21	9
18	21	9
19	21	9
20	21	9
21	21	9
22	21	9
23	22	9
24	22	9
25	22	10
26	22	10
27	22	10
28	22	10
29	22	10
30	22	10

	Clearer (%)	Cloudier (%)
1	74	26
2	74	26
3	74	26
4	73	27
5	73	27
6	73	27
7	73	27
8	74	26
9	74	26
10	74	26
11	73	27
12	74	26
13	74	26
14	74	26
15	74	26
16	74	26
17	74	26
18	74	26
19	73	27
20	73	27
21	73	27
22	72	28
23	71	29
24	71	29
25	70	30
26	69	31
27	68	32
28	68	32
29	68	32
30	67	33

	Rain chance (%)
1	11
2	11
3	11
4	11
5	12
6	12
7	12
8	13
9	13
10	13
11	13
12	14
13	14
14	14
15	15
16	15
17	15
18	16
19	16
20	17
21	17
22	18
23	18
24	19
25	20
26	20
27	21
28	21
29	21
30	22

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	99	1
16	99	1
17	99	1
18	99	1
19	99	1
20	99	1
21	99	1
22	99	1
23	99	1
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	98	2

	Avg high (°C)	Avg low (°C)
1	20	7
2	20	8
3	20	8
4	20	8
5	20	8
6	20	8
7	20	8
8	20	8
9	20	8
10	20	8
11	20	8
12	20	8
13	21	8
14	21	8
15	21	9
16	21	9
17	21	9
18	21	9
19	21	9
20	21	9
21	21	9
22	21	9
23	22	9
24	22	9
25	22	10
26	22	10
27	22	10
28	22	10
29	22	10
30	22	10

	Clearer (%)	Cloudier (%)
1	74	26
2	74	26
3	74	26
4	73	27
5	73	27
6	73	27
7	73	27
8	74	26
9	74	26
10	74	26
11	73	27
12	74	26
13	74	26
14	74	26
15	74	26
16	74	26
17	74	26
18	74	26
19	73	27
20	73	27
21	73	27
22	72	28
23	71	29
24	71	29
25	70	30
26	69	31
27	68	32
28	68	32
29	68	32
30	67	33

	Rain chance (%)
1	11
2	11
3	11
4	11
5	12
6	12
7	12
8	13
9	13
10	13
11	13
12	14
13	14
14	14
15	15
16	15
17	15
18	16
19	16
20	17
21	17
22	18
23	18
24	19
25	20
26	20
27	21
28	21
29	21
30	22

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	99	1
16	99	1
17	99	1
18	99	1
19	99	1
20	99	1
21	99	1
22	99	1
23	99	1
24	99	1
25	99	1
26	99	1
27	99	1
28	99	1
29	99	1
30	98	2