Castaños weather in September

In September, Castaños sees average daytime highs of 28°C and overnight lows near 19°C, with 121 mm of rain across 13 wet days and about 12.2 hours of daylight. It is the 6th-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 30°C in the first days to 27°C by the end. The sky is clear or mostly clear about 43% of the time in September, and the air most often feels muggy.

Daylight stretches from about 12 h 36 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Castaños's 12th-clearest and 8th-windiest month. For the whole year in context, see Castaños's year-round climate.

Daytime high
28°
6th warmest
Overnight low
19°
8th coldest
Rainfall
121 mm
13 wet days
Daylight
12 h 12 min
6:35 AM – 6:45 PM
Cloud cover
50%
12th clearest
Wind
7 km/h
8th windiest
Solar energy
5.34 kWh/m²
Travel score
5.6
out of 10

Castaños is municipal seat of Castaños, State of Coahuila, Mexico.

Founded
1674

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 30°C in the first days to 27°C by the end.

A typical September day in Castaños reaches about 28°C in the afternoon and slips back to 19°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 33°C. Set against its neighbours, September runs about 3°C cooler than August and about 2°C warmer than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13021
23021
33021
43021
53020
62920
72920
82920
92920
102920
112920
122920
132920
142820
152819
162819
172819
182819
192819
202819
212819
222819
232818
242818
252818
262818
272818
282818
292718
302718

How September really feels in Castaños

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.

Castaños weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 173.610.57.2
Feb22° / 123.111.18.0
Mar25° / 13°244.311.88.0
Apr29° / 16°275.812.66.2
May32° / 20°4911.613.34.3
Jun33° / 22°5610.213.73.8
Jul32° / 22°8110.213.54.0
Aug32° / 22°649.212.94.3
Sep28° / 19°1211312.25.6
Oct26° / 15°396.711.47.6
Nov22° / 11°213.910.78.0
Dec19° / 193.410.37.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 37%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16238
26139
36040
46040
55941
65941
75842
85842
95842
105941
115941
125941
135941
146040
156040
166040
176139
186139
196337
206337
216436
226535
236733
246832
256931
267030
277129
287327
297327
307327

Chance of precipitation in September

Any precipitation

Castaños gets around 121 mm of rain over 13 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 42% and peaks near 50% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
143
244
345
447
548
649
749
849
950
1049
1149
1248
1348
1447
1546
1645
1744
1843
1942
2040
2139
2237
2336
2434
2533
2632
2730
2830
2929
3028

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 43% of days. Sticky, muggy-or-worse air turns up on roughly 46% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
141436434
241335444
341334454
441333464
541232474
641231485
741230495
841230495
941229505
1041229505
1151229505
1251229505
1351229505
1451229494
1551329494
1661330484
1761330473
1871431463
1981431442
2091531432
21101631412
22111731402
23121831381
24131831361
25151931341
26162031331
27172130311
28182130301
29192230291
30202329271

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 36 min at the start of September to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 48 minutes over September. Sunrise moves from 6:29 AM to 6:42 AM, and sunset from 7:02 PM to 6:28 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:297:02
212.56:297:01
312.56:307:00
412.56:306:59
512.56:316:58
612.46:316:56
712.46:316:55
812.46:326:54
912.36:326:53
1012.36:336:52
1112.36:336:51
1212.36:346:49
1312.26:346:48
1412.26:346:47
1512.26:356:46
1612.26:356:45
1712.16:366:44
1812.16:366:42
1912.16:376:41
2012.06:376:40
2112.06:386:39
2212.06:386:38
2312.06:386:36
2411.96:396:35
2511.96:396:34
2611.96:406:33
2711.96:406:32
2811.86:416:31
2911.86:416:29
3011.86:426:28

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.34 kWh/m².

For context, solar energy here swings from a low near 3.69 kWh/m² to a high of 7.06 kWh/m² in June across the year — September's 5.34 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.9Bright
25.8Bright
35.8Bright
45.7Bright
55.6Bright
65.6Bright
75.5Bright
85.5Bright
95.5Bright
105.4Bright
115.4Bright
125.4Bright
135.4Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.3Bright
285.3Bright
295.3Bright
305.2Bright
Planning a trip in September

Hazard calendar for Castaños

In seasonPeak

In September, Castaños sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Castaños's rainy season runs June–September, 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 Castaños?

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

5.6
Sightseeing
8th-best month of the year
6.6
Beach & pool
6th-best month of the year

September is a reasonable time to visit Castaños for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Castaños in September

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

In September, Castaños sees daytime highs around 28°C and nights near 19°C. Pack light clothes. Worth having: rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

UV index in Castaños in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Castaños peaks around July 15 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 5 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJul 15UV 12Dec 17UV 5
UV index (midday)Level
Jan6High
Feb7Very high
Mar9Very high
Apr11Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug11Extreme
Sep11Extreme
Oct8Very high
Nov6High
Dec5Moderate

Air quality in Castaños 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 Castaños is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (January, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1617 µg/m³Jan 219 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb9Good
Mar9Good
Apr11Good
May15Moderate
Jun15Moderate
Jul18Moderate
Aug15Moderate
Sep14Moderate
Oct11Good
Nov10Good
Dec9Good
Location & terrain

Where is Castaños?

Castaños sits at 26.8°N, 101.4°W, 756 m above sea level, in Mexico. The nearest listed city is Monclova, 13 km away.

Topography around Castaños

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

Within 3 km, the terrain around Castaños has only modest variations in elevation — a maximum elevation change of 240 m around an average of 777 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,344 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,316 m.

The land around Castaños is covered by shrubs (58%) and artificial surfaces (26%) within 3 km, shrubs (81%) within 16 km, and shrubs (88%) within 80 km.

3 km
240 m
16 km
1,344 m
80 km
2,316 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
September weather nearby: Monclova 13 km · Frontera 16 km · San Buenaventura 32 km · Ciudad Melchor Múzquiz 121 km · Sabinas 123 km · Palaú 123 km · Ciudad Sabinas Hidalgo 128 km · Nueva Rosita 129 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 Castaños (26.7893°, -101.4321°, elevation 756 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).