San Cristóbal de las Casas weather in September

In September, San Cristóbal de las Casas sees average daytime highs of 25°C and overnight lows near 16°C, with 429 mm of rain across 26.3 wet days and about 12.1 hours of daylight. It is the 8th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 5% of the time in September, and the air most often feels humid.

Daylight stretches from about 12 h 18 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is San Cristóbal de las Casas's 12th-clearest and 11th-windiest month. For the whole year in context, see San Cristóbal de las Casas's year-round climate.

Daytime high
25°
8th warmest
Overnight low
16°
10th coldest
Rainfall
429 mm
26.3 wet days
Daylight
12 h 06 min
6:02 AM – 6:08 PM
Cloud cover
84%
12th clearest
Wind
4 km/h
11th windiest
Solar energy
4.85 kWh/m²
Travel score
4.1
out of 10

San Cristóbal de las Casas is municipal seat of San Cristóbal, State of Chiapas, Mexico.

Founded
1528

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 25°C through the month.

A typical September day in San Cristóbal de las Casas reaches about 25°C in the afternoon and slips back to 16°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 26°C. Set against its neighbours, September runs about 1°C cooler than August and on par with October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12516
22516
32516
42516
52516
62516
72516
82516
92516
102516
112516
122516
132516
142516
152516
162516
172516
182516
192516
202516
212416
222416
232416
242416
252416
262416
272416
282416
292416
302416

San Cristóbal de las Casas weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan24° / 12°122.611.18.6
Feb26° / 13°71.711.48.5
Mar27° / 14°183.711.97.8
Apr28° / 15°508.612.46.7
May27° / 16°22319.212.85.1
Jun25° / 16°48625.7134.1
Jul25° / 16°30021.612.94.8
Aug25° / 16°36323.212.64.6
Sep25° / 16°42926.312.14.1
Oct24° / 15°23018.111.65.5
Nov24° / 14°587.911.27.5
Dec24° / 13°182.6118.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 5% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 8% of September, with mostly cloudy or overcast conditions the remaining 88%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11486
21486
31387
41387
51387
61288
71288
81288
91288
101288
111288
121288
131288
141288
151288
161288
171288
181288
191288
201288
211288
221288
231288
241387
251387
261387
271387
281486
291684
301684

Chance of precipitation in September

Any precipitation

San Cristóbal de las Casas gets around 429 mm of rain over 26.3 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 86% and peaks near 88% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
187
287
387
488
588
688
787
887
987
1087
1186
1286
1386
1486
1586
1686
1787
1887
1987
2087
2187
2287
2387
2487
2586
2686
2785
2884
2983
3081

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the humid band about 86% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1116821
2115831
3114841
4114841
5113851
6113851
7113851
8113851
9112861
10112861
11112861
12112861
13112861
14112861
15012871
16012871
17012871
18011881
19011881
20011881
21011881
22011881
23011881
24011881
25112861
26112861
27112861
28113851
29113851
30214831

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 18 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 24 minutes over September. Sunrise moves from 6:00 AM to 6:04 AM, and sunset from 6:20 PM to 5:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.36:006:20
212.36:006:19
312.36:016:19
412.36:016:18
512.36:016:17
612.36:016:16
712.26:016:15
812.26:016:14
912.26:016:14
1012.26:016:13
1112.26:026:12
1212.26:026:11
1312.16:026:10
1412.16:026:09
1512.16:026:09
1612.16:026:08
1712.16:026:07
1812.16:026:06
1912.06:026:05
2012.06:036:04
2112.06:036:03
2212.06:036:03
2312.06:036:02
2412.06:036:01
2511.96:036:00
2611.96:035:59
2711.96:035:58
2811.96:045:58
2911.96:045:57
3011.96:045:56

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.85 kWh/m².

For context, solar energy here swings from a low near 4.57 kWh/m² to a high of 6.65 kWh/m² in April across the year — September's 4.85 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.1Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
164.9Bright
174.9Bright
184.9Bright
194.8Bright
204.8Bright
214.8Bright
224.7Bright
234.7Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.5Bright
294.5Bright
304.5Bright
Planning a trip in September

Hazard calendar for San Cristóbal de las Casas

In seasonPeak

In September, San Cristóbal de las Casas sits inside its monsoon season. The full year is below, with each hazard's peak months called out.

San Cristóbal de las Casas's monsoon runs May–October, when most of the year's rain falls.

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

Is September a good time to visit San Cristóbal de las Casas?

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

4.1
Sightseeing
11th-best month of the year
3.7
Beach & pool
12th-best month of the year

September is a reasonable time to visit San Cristóbal de las Casas for sightseeing.

What to pack for San Cristóbal de las Casas in September

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

In September, San Cristóbal de las Casas sees daytime highs around 25°C and nights near 16°C. Pack rain gear. Worth having: light clothes and sun protection. About 26 days see rain.

rain gearlight clothessun protection

UV index in San Cristóbal de las Casas in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Cristóbal de las Casas peaks around April 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highApr 12UV 14Dec 17UV 8
UV index (midday)Level
Jan9Very high
Feb13Extreme
Mar14Extreme
Apr14Extreme
May11Extreme
Jun14Extreme
Jul13Extreme
Aug13Extreme
Sep13Extreme
Oct11Extreme
Nov9Very high
Dec8Very high

Air quality in San Cristóbal de las Casas 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 San Cristóbal de las Casas is worst in April — around 38 µg/m³ PM2.5 (poor), about 3.1× the cleanest month (December, 12 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateApr 2337 µg/m³Dec 1612 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb21Moderate
Mar27Moderate
Apr38Poor
May37Poor
Jun21Moderate
Jul24Moderate
Aug20Moderate
Sep19Moderate
Oct15Moderate
Nov13Moderate
Dec12Moderate
Location & terrain

Where is San Cristóbal de las Casas?

San Cristóbal de las Casas sits at 16.7°N, 92.6°W, 2,183 m above sea level, in Mexico. The nearest listed city is Teopisca, 27 km away.

Topography around San Cristóbal de las Casas

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Cristóbal de las Casas.

Within 3 km, the terrain around San Cristóbal de las Casas has significant variations in elevation — a maximum elevation change of 392 m around an average of 2,158 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,344 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,842 m.

The land around San Cristóbal de las Casas is covered by artificial surfaces (60%) and trees (26%) within 3 km, trees (58%) and grassland (30%) within 16 km, and trees (62%) and grassland (27%) within 80 km.

3 km
392 m
16 km
2,344 m
80 km
2,842 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Teopisca 27 km · Chiapas 40 km · Venustiano Carranza 44 km · Las Rosas 50 km · Suchiapa 50 km · Tuxtla 51 km · Yajalón 59 km · Ocosingo 61 km

Mexico travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B
120 / 127 V · 60 Hz
Prices
≈ 54% of US
price level, 2025
GDP per capita
$13,889
2025
Happiness
7.0 / 10
World Happiness, 2025
Safe drinking water
43%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
12.8
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 440
Religion
Catholic 78%no religion 11%other Evangelical Churches 8%Jehovah Witness 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 San Cristóbal de las Casas (16.7301°, -92.6382°, elevation 2,183 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).