Monthly climate guide
Hermosillo weather in September
With highs near 37°C (98°F) and lows around 24°C (76°F), September feels very hot in Hermosillo. Rainfall averages about 90 mm (wet) and the sky is mostly sunny. Daytime highs are about the same as August and 2°C warmer than October.
What stands out in September
- Even after dark it stays around 24°C, so sleeping can feel warm.
- Hermosillo is usually about 5°C warmer than Nogales, 250 km away, in September.
- It's wetter than a typical month in Hermosillo — roughly 175% more rain than average.
- Seasonally, September counts as early autumn in Hermosillo.
Avg high
37°C
98°F
Avg low
24°C
76°F
Rainfall
90 mm
wet
Humidity
58%
relative
Sky
34%
cloud · mostly sunny
Hermosillo weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 25°C / 78°F | 10°C / 50°F | 15 mm | 42% | 29% |
| February | 27°C / 80°F | 11°C / 51°F | 10 mm | 41% | 33% |
| March | 30°C / 86°F | 13°C / 56°F | 13 mm | 36% | 31% |
| April | 33°C / 91°F | 15°C / 60°F | 2 mm | 31% | 22% |
| May | 35°C / 95°F | 18°C / 64°F | 1 mm | 30% | 14% |
| June | 40°C / 105°F | 24°C / 75°F | 11 mm | 33% | 21% |
| July | 38°C / 100°F | 26°C / 79°F | 107 mm | 53% | 60% |
| August | 37°C / 99°F | 26°C / 79°F | 95 mm | 58% | 51% |
| September | 37°C / 98°F | 24°C / 76°F | 90 mm | 58% | 34% |
| October | 34°C / 94°F | 20°C / 67°F | 10 mm | 46% | 19% |
| November | 29°C / 84°F | 15°C / 59°F | 24 mm | 43% | 30% |
| December | 24°C / 75°F | 10°C / 51°F | 15 mm | 47% | 34% |
What to pack for September
- Light, breathable clothing (cotton or linen)
- A sun hat and high-SPF sunscreen
- A refillable water bottle
- An extra layer — evenings are noticeably cooler than afternoons
- A compact umbrella or packable rain jacket
- Water-resistant shoes
- Sunglasses
Is September a good time to visit Hermosillo?
Compare the months in the chart above to find your ideal window.
Best time to visit Hermosillo →Other Mexico cities in September
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Hermosillo weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/mexico/hermosillo/september
<a href="https://weathercompare.eu/weather/mexico/hermosillo/september">Hermosillo weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/mexico/hermosillo" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Hermosillo weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/mexico/hermosillo/september">Hermosillo weather in September</a> – WeatherCompare</p>
Hermosillo in September: quick answers
Is September a good time to visit Hermosillo?
It can be, if you like heat: September highs in Hermosillo are around 37°C. Good for the beach; plan sightseeing for early morning and evening.
How warm is Hermosillo in September?
Average highs are about 37°C (98°F) and average lows about 24°C (76°F), based on 10 years of daily data.
Does it rain a lot in Hermosillo in September?
Hermosillo typically gets around 90 mm of rain in September — wet.
Figures are long-term averages for the area around Hermosillo (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.