El Rosario weather in September

In September, El Rosario sees average daytime highs of 30°C and overnight lows near 23°C, with 244 mm of rain across 24.3 wet days and about 12.1 hours of daylight. It is the 6th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 7% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 30 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is El Rosario's 10th-clearest and 11th-windiest month. For the whole year in context, see El Rosario's year-round climate.

Daytime high
30°
6th warmest
Overnight low
23°
10th coldest
Rainfall
244 mm
24.3 wet days
Daylight
12 h 06 min
5:54 AM – 6:02 PM
Cloud cover
77%
10th clearest
Wind
4 km/h
11th windiest
Solar energy
4.61 kWh/m²
Travel score
3.2
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical September day in El Rosario reaches about 30°C in the afternoon and slips back to 23°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 32°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13023
23023
33023
43023
53023
63023
73023
83023
93023
103023
113023
123023
133023
143023
153023
163023
173023
183023
193023
203023
213023
223023
233023
243023
253023
263023
273023
283023
293023
303023

How September really feels in El Rosario

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
heat index over the day's high
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.

El Rosario weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 13°202.110.78.1
Feb27° / 13°191.411.28.1
Mar29° / 14°50.611.87.4
Apr30° / 16°10.212.56.3
May32° / 19°30.513.15.2
Jun32° / 23°709.313.44.1
Jul31° / 23°2362413.33.0
Aug30° / 23°28126.112.82.9
Sep30° / 23°24424.312.13.2
Oct30° / 21°9211.311.55.0
Nov29° / 17°302.610.96.9
Dec27° / 14°182.310.68.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 7% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 75%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11486
21486
31684
41684
51684
61783
71882
81882
92080
102080
112080
122179
132179
142278
152377
162377
172575
182575
192575
202674
212773
223070
233169
243367
253466
263763
273862
284159
294357
304456

Chance of precipitation in September

Any precipitation

El Rosario gets around 244 mm of rain over 24.3 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 80% and peaks near 89% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
189
289
389
489
589
689
788
888
987
1086
1186
1285
1384
1483
1583
1682
1781
1880
1979
2078
2177
2276
2374
2473
2571
2670
2768
2867
2965
3063

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 52% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
104753
204753
304753
404753
504753
604852
704852
804852
904852
1004852
1104852
1204852
1304852
1404852
1504753
1604753
1704753
1804654
1904654
2004654
2114653
2214752
2314752
2414752
2514851
2614950
2715049
2825048
2925246
3025345

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 30 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 42 minutes over September. Sunrise moves from 5:49 AM to 5:58 AM, and sunset from 6:17 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.55:496:17
212.45:496:16
312.45:506:15
412.45:506:14
512.45:506:13
612.45:516:12
712.35:516:11
812.35:516:10
912.35:526:09
1012.35:526:08
1112.25:526:07
1212.25:536:06
1312.25:536:05
1412.25:536:04
1512.25:536:03
1612.15:546:02
1712.15:546:01
1812.15:546:00
1912.15:555:59
2012.05:555:57
2112.05:555:56
2212.05:565:55
2312.05:565:54
2411.95:565:53
2511.95:575:52
2611.95:575:51
2711.95:575:50
2811.95:585:49
2911.85:585:48
3011.85:585:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.61 kWh/m².

For context, solar energy here swings from a low near 4.33 kWh/m² to a high of 7.68 kWh/m² in May across the year — September's 4.61 kWh/m² sits near the bottom.

024151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.6Bright
104.6Bright
114.6Bright
124.6Bright
134.6Bright
144.6Bright
154.6Bright
164.6Bright
174.6Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.7Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
Planning a trip in September

Hazard calendar for El Rosario

In seasonPeak

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

El Rosario sits in the eastern Pacific hurricane zone; the season peaks August–September.

El Rosario's monsoon runs July–September, when most of the year's rain falls.

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

Is September a good time to visit El Rosario?

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

3.2
Sightseeing
10th-best month of the year
4.5
Beach & pool
10th-best month of the year

September is a weaker month for outdoor sightseeing in El Rosario.

What to pack for El Rosario in September

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

In September, El Rosario sees daytime highs around 30°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.

light clothesrain gearsun protection

Sea temperature near El Rosario 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 at the nearest coast (about 31 km away) is warmest in August at about 30°C and coldest in March near 23°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan24Refreshing
Feb23Refreshing
Mar23Refreshing
Apr23Refreshing
May26Warm
Jun28Warm
Jul29Tropical
Aug30Tropical
Sep30Tropical
Oct30Tropical
Nov28Warm
Dec25Warm

UV index in El Rosario 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 El Rosario peaks around May 17 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighMay 17UV 12Dec 20UV 6
UV index (midday)Level
Jan6High
Feb9Very high
Mar10Extreme
Apr12Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug12Extreme
Sep11Extreme
Oct8Very high
Nov6High
Dec6High

Air quality in El Rosario 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 El Rosario is worst in May — around 22 µg/m³ PM2.5 (moderate), about 3.8× the cleanest month (January, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 1821 µg/m³Jan 166 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb6Good
Mar7Good
Apr11Good
May22Moderate
Jun14Moderate
Jul8Good
Aug8Good
Sep9Good
Oct8Good
Nov7Good
Dec6Good
Location & terrain

Where is El Rosario?

El Rosario sits at 23.0°N, 105.9°W, 33 m above sea level, in Mexico. The nearest listed city is Escuinapa de Hidalgo, 19 km away.

Topography around El Rosario

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

Within 3 km, the terrain around El Rosario has only modest variations in elevation — a maximum elevation change of 222 m around an average of 42 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 915 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,912 m.

The land around El Rosario is covered by trees (43%) and cropland (25%) within 3 km, trees (68%) within 16 km, and trees (59%) and water (25%) within 80 km.

3 km
222 m
16 km
915 m
80 km
2,912 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwatermangroves
September weather nearby: Escuinapa de Hidalgo 19 km · Mazatlan 63 km · Pueblo Nuevo 66 km · Acaponeta 75 km · El Salto 101 km · Tuxpan 130 km · Santiago Ixcuintla 147 km · La Cruz 148 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 El Rosario (22.9903°, -105.8542°, elevation 33 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).