San Carlos weather in September

In September, San Carlos sees average daytime highs of 34°C and overnight lows near 27°C, with 62 mm of rain across 5.4 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 34°C through the month. The sky is clear or mostly clear about 77% of the time in September, and the air most often feels miserable.

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 San Carlos's 4th-clearest and 10th-windiest month. For the whole year in context, see San Carlos's year-round climate.

Daytime high
34°
3rd warmest
Overnight low
27°
10th coldest
Rainfall
62 mm
5.4 wet days
Daylight
12 h 12 min
6:14 AM – 6:23 PM
Cloud cover
24%
4th clearest
Wind
12 km/h
10th windiest
Solar energy
5.94 kWh/m²
Travel score
3.7
out of 10

San Carlos is town in Guaymas Municipality, State of Sonora, Mexico.

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 34°C through the month.

A typical September day in San Carlos reaches about 34°C in the afternoon and slips back to 27°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 31°C and 37°C. Set against its neighbours, September runs about 1°C cooler than August and about 2°C warmer than October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13428
23428
33428
43428
53428
63428
73428
83428
93428
103428
113428
123428
133428
143428
153428
163428
173427
183427
193427
203427
213427
223427
233427
243427
253427
263426
273426
283426
293426
303326

How September really feels in San Carlos

Once humidity and wind are folded in, September averages 30 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
30
26 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

San Carlos weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan23° / 12°6110.48.8
Feb24° / 13°71.2118.8
Mar26° / 15°40.511.88.8
Apr28° / 18°10.312.67.9
May31° / 21°0013.46.1
Jun34° / 26°10.213.74.3
Jul35° / 29°102.413.63.1
Aug35° / 29°224.2133.0
Sep34° / 27°625.412.23.7
Oct32° / 23°182.311.35.5
Nov27° / 17°121.310.68.1
Dec23° / 13°101.210.38.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 77% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 8% of September, with mostly cloudy or overcast conditions the remaining 14%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17822
27822
37921
47921
58020
68020
78218
88218
98218
108416
118416
128515
138614
148713
158713
168713
178812
188812
198812
208911
218911
228911
238911
248911
258911
268911
279010
289010
299010
309010

Chance of precipitation in September

Any precipitation

San Carlos gets around 62 mm of rain over 5.4 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 18% and peaks near 23% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
123
223
323
423
523
622
722
821
921
1020
1120
1219
1319
1418
1518
1617
1717
1816
1916
2016
2115
2215
2315
2415
2514
2614
2714
2813
2912
3012

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the miserable band about 68% of days. Sticky, muggy-or-worse air turns up on roughly 96% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10131185
20131185
30131185
40131185
50131185
60131284
70131284
80231382
90231382
100231481
110241579
120241579
130241678
140251776
150351874
160361972
170372169
180382267
191392364
2013102462
2114112559
2214122558
2314132656
2414142754
2515162850
2625172948
2726182945
2826203042
2937213039
3038233036

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
113light breeze
213light breeze
312light breeze
412light breeze
512light breeze
612light breeze
712light breeze
812light breeze
912light breeze
1012light breeze
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

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 6:06 AM to 6:21 AM, and sunset from 6:41 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:066:41
212.66:076:40
312.56:076:39
412.56:086:38
512.56:086:37
612.46:096:36
712.46:096:34
812.46:106:33
912.46:106:32
1012.36:116:31
1112.36:116:30
1212.36:126:28
1312.26:126:27
1412.26:136:26
1512.26:136:25
1612.26:146:23
1712.16:146:22
1812.16:156:21
1912.16:156:20
2012.06:166:19
2112.06:166:17
2212.06:166:16
2312.06:176:15
2411.96:176:14
2511.96:186:12
2611.96:186:11
2711.96:196:10
2811.86:206:09
2911.86:206:08
3011.86:216:06

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.94 kWh/m².

For context, solar energy here swings from a low near 3.93 kWh/m² to a high of 8.15 kWh/m² in May across the year — September's 5.94 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.1Intense
46.0Intense
56.0Intense
66.0Intense
76.0Intense
86.0Intense
96.0Intense
106.0Intense
116.0Intense
126.0Intense
136.0Bright
146.0Bright
156.0Bright
166.0Bright
176.0Bright
185.9Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.9Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Hazard calendar for San Carlos

In seasonPeak

In September, San Carlos sits inside its pacific hurricane season. The full year is below, with each hazard's peak months called out.

San Carlos sits in the eastern Pacific hurricane zone; the season peaks August–September.

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

Is September a good time to visit San Carlos?

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

3.7
Sightseeing
10th-best month of the year
7.2
Beach & pool
8th-best month of the year

September is a weaker month for outdoor sightseeing in San Carlos. The water and warmth also suit a beach or pool day.

What to pack for San Carlos in September

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

In September, San Carlos sees daytime highs around 34°C and nights near 27°C. Pack light clothes. Worth having: sun protection. About 5 days see rain.

light clothessun protection

Sea temperature near San Carlos in September

The nearest coast averages about 30°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 30°C and coldest in February near 18°C.

It's comfortable for a long swim from Apr 6 to Dec 16 — about 8.4 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan18Cool
Feb18Cool
Mar19Cool
Apr21Refreshing
May24Refreshing
Jun27Warm
Jul29Tropical
Aug30Tropical
Sep30Tropical
Oct28Warm
Nov23Refreshing
Dec20Cool

UV index in San Carlos 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 San Carlos peaks around July 14 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighModerateJul 14UV 12Dec 19UV 4
UV index (midday)Level
Jan5Moderate
Feb6High
Mar8Very high
Apr10Very high
May10Extreme
Jun12Extreme
Jul12Extreme
Aug11Extreme
Sep10Very high
Oct7Very high
Nov5High
Dec4Moderate

Air quality in San Carlos 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 Carlos is worst in July — around 18 µg/m³ PM2.5 (moderate), about 3.9× the cleanest month (January, 5 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1917 µg/m³Jan 115 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb5Good
Mar5Good
Apr6Good
May5Good
Jun8Good
Jul18Moderate
Aug13Moderate
Sep8Good
Oct5Good
Nov5Good
Dec5Good
Location & terrain

Where is San Carlos?

San Carlos sits at 28.0°N, 111.0°W, 0 m above sea level, in Mexico. The nearest listed city is Heroica Guaymas, 15 km away.

NavojoaHuatabampo

Topography around San Carlos

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

Within 3 km, the terrain around San Carlos has only modest variations in elevation — a maximum elevation change of 236 m around an average of 23 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 838 m; within 80 km, large variations in elevation — a maximum elevation change of 1,146 m.

The land around San Carlos is covered by water (40%) and shrubs (39%) within 3 km, shrubs (46%) and water (46%) within 16 km, and shrubs (46%) and water (42%) within 80 km.

3 km
236 m
16 km
838 m
80 km
1,146 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Heroica Guaymas 15 km · Empalme 23 km · Miguel Alemán (La Doce) 107 km · Esperanza 117 km · Ciudad Obregón 121 km · Hermosillo 126 km · Navojoa 186 km · Huatabampo 187 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 Carlos (27.9575°, -111.0435°, elevation 0 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).