Hermosillo weather in September

In September, Hermosillo sees average daytime highs of 37°C and overnight lows near 25°C, with 52 mm of rain across 7.1 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 37°C through the month. The sky is clear or mostly clear about 75% of the time in September, and the air most often feels oppressive.

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 Hermosillo's 6th-clearest and 11th-windiest month. For the whole year in context, see Hermosillo's year-round climate.

Daytime high
37°
4th warmest
Overnight low
25°
10th coldest
Rainfall
52 mm
7.1 wet days
Daylight
12 h 12 min
6:13 AM – 6:23 PM
Cloud cover
28%
6th clearest
Wind
8 km/h
11th windiest
Solar energy
5.94 kWh/m²
Travel score
2.0
out of 10

Hermosillo is city in Mexico, Sonora state capital.

Founded
1700

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 37°C through the month.

A typical September day in Hermosillo reaches about 37°C in the afternoon and slips back to 25°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 32°C and 40°C. Set against its neighbours, September runs about 1°C cooler than August and about 3°C warmer than October.

20°30°40°151015202530
Avg high (°C)Avg low (°C)
13726
23726
33726
43726
53726
63726
73726
83726
93725
103725
113725
123725
133725
143725
153725
163725
173725
183725
193724
203724
213724
223624
233624
243624
253624
263623
273623
283623
293623
303623

How September really feels in Hermosillo

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
19 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.

Hermosillo weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan24° / 121.610.38.9
Feb26° / 10°152118.4
Mar29° / 12°70.911.87.3
Apr32° / 15°10.412.75.3
May36° / 18°00.113.43.0
Jun39° / 24°31.113.80.7
Jul39° / 27°407.613.70.8
Aug38° / 27°519.8131.2
Sep37° / 25°527.112.22.0
Oct34° / 19°192.111.34.1
Nov28° / 13°131.510.57.4
Dec24° / 191.910.28.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 75% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 11% of September, with mostly cloudy or overcast conditions the remaining 15%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17723
27822
37921
48020
58119
68119
78317
88317
98416
108515
118515
128614
138614
148614
158614
168614
178713
188713
198713
208713
218713
228713
238713
248713
258812
268812
278911
288911
298911
308911

Chance of precipitation in September

Any precipitation

Hermosillo gets around 52 mm of rain over 7.1 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 24% and peaks near 34% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
134
234
334
433
533
632
731
831
930
1029
1128
1227
1326
1425
1524
1623
1722
1821
1920
2019
2119
2218
2317
2417
2516
2615
2715
2814
2913
3013

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 43% of days. Sticky, muggy-or-worse air turns up on roughly 76% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1225125821
2225125821
3225125821
4225125821
5226125721
6326135621
7326135620
8326145619
9337155319
10437165218
11437175217
12448175116
13548185015
14559194814
15659204713
167610214512
178610224311
188711224110
199811233910
201091224379
211191225358
2211101226338
2312111326317
2413111327297
2514121327276
2615131427256
2716141428245
2817151428225
2919151428204
3021161428184

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

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 6:05 AM to 6:21 AM, and sunset from 6:42 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:056:42
212.66:066:41
312.66:066:40
412.56:076:38
512.56:076:37
612.56:086:36
712.46:086:35
812.46:096:33
912.46:096:32
1012.46:106:31
1112.36:106:30
1212.36:116:28
1312.36:116:27
1412.26:126:26
1512.26:136:25
1612.26:136:23
1712.16:146:22
1812.16:146:21
1912.16:156:20
2012.16:156:18
2112.06:166:17
2212.06:166:16
2312.06:176:14
2411.96:176:13
2511.96:186:12
2611.96:186:11
2711.86:196:09
2811.86:196:08
2911.86:206:07
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 3.81 kWh/m² to a high of 8.27 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
46.1Intense
56.1Intense
66.0Intense
76.0Intense
86.0Intense
96.0Intense
106.0Intense
116.0Intense
126.0Bright
136.0Bright
146.0Bright
156.0Bright
166.0Bright
175.9Bright
185.9Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Is September a good time to visit Hermosillo?

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

2.0
Sightseeing
9th-best month of the year
5.2
Beach & pool
9th-best month of the year

September is a weaker month for outdoor sightseeing in Hermosillo.

What to pack for Hermosillo in September

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

In September, Hermosillo sees daytime highs around 37°C and nights near 25°C. Pack light clothes. Worth having: sun protection. About 7 days see rain.

light clothessun protection

UV index in Hermosillo 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 Hermosillo peaks around July 11 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 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 11UV 12Dec 18UV 4
UV index (midday)Level
Jan5Moderate
Feb6High
Mar8Very high
Apr10Extreme
May10Extreme
Jun12Extreme
Jul12Extreme
Aug11Extreme
Sep10Very high
Oct7High
Nov5High
Dec4Moderate
Location & terrain

Where is Hermosillo?

Hermosillo sits at 29.1°N, 111.0°W, 202 m above sea level, in Mexico. The nearest listed city is Miguel Alemán (La Doce), 57 km away.

EsperanzaCiudad ObregónHeroica Caborca

Topography around Hermosillo

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

Within 3 km, the terrain around Hermosillo has only modest variations in elevation — a maximum elevation change of 142 m around an average of 213 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 530 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,508 m.

The land around Hermosillo is covered by artificial surfaces (89%) within 3 km, shrubs (63%) within 16 km, and shrubs (85%) within 80 km.

3 km
142 m
16 km
530 m
80 km
1,508 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
September weather nearby: Miguel Alemán (La Doce) 57 km · San Carlos 126 km · Empalme 126 km · Heroica Guaymas 130 km · Magdalena de Kino 171 km · Esperanza 196 km · Ciudad Obregón 205 km · Heroica Caborca 215 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 Hermosillo (29.0887°, -110.9668°, elevation 202 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).