September Weather in Hermosillo, Mexico

Last updated: April 22, 2025

September in Hermosillo, Mexico presents a warm embrace, with maximum temperatures reaching 31°C (88°F) and an average of 24°C (75°F). While the days are typically sunny, the month experiences significant precipitation, totaling 683 mm (26.9 in) over 29 days, resulting in an humidity level of 82%. This combination of warmth and moisture creates a unique climate, ideal for those who appreciate the lush landscapes that emerge from seasonal rains. Prepare for an engaging month where sunshine meets refreshing showers in this vibrant desert city.

September Temperature in Hermosillo

In Hermosillo, Mexico, September marks a transition as the summer heat begins to wane. With minimum temperatures around 17°C (63°F) and an average of 24°C (75°F), the city still enjoys warm weather, but the maximum temperature dips to a comfortable 31°C (88°F). This gradual cooling trend is in line with the shift observed from the scorching summer months of June, July, and August, where temperatures frequently soared above 32°C (90°F). As September unfolds, residents and visitors alike can relish the balmy evenings and pleasant afternoons, making it an ideal time to explore the vibrant local culture and stunning landscapes without the intensity of peak summer heat.

September Weather in Hermosillo: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Hermosillo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec737576777775767575757473
Data source: Temperature data for Hermosillo generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Hermosillo

In September, Hermosillo experiences a remarkable peak in precipitation, with a staggering 683 mm (26.9 in) of rainfall recorded over the month. This substantial accumulation marks a continuation of the region's wettest season, following August, which already saw 590 mm (23.2 in). With 29 rainy days, September sustains the high frequency of rainfall typical for this time of year, making it a critical period for replenishing local water sources. As the summer monsoon wanes, the trend highlights the stark contrast in hydrological patterns across the months, with September firmly establishing itself as the climax of Hermosillo's rainy season, bringing both relief and challenges to the region's landscape.

September Precipitation Trends in Hermosillo

The chart displays monthly precipitation patterns in Hermosillo, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec27153812053355346059068365827648
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Hermosillo

In September, Hermosillo experiences a notable spike in humidity, reaching 82%, which is consistent with the summer months of July and August. This increase highlights a trend of rising humidity levels as the region transitions from the dry heat of summer to the cooler fall season. Following this peak, there is a gradual rise in humidity into October at 83%, indicating that the lingering warmth carries with it significant moisture. The fluctuation in humidity throughout the year showcases the typical desert climate's transition, which may surprise those accustomed to arid conditions, yet provides a unique character to the weather of Hermosillo.

September Average Humidity in Hermosillo

This chart illustrates the average monthly humidity levels in Hermosillo, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec76%68%59%57%65%66%75%82%82%83%80%76%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hermosillo

In September, Hermosillo, Mexico, experiences a notably high UV Index of 14, categorizing it within the extreme exposure bracket, with a burn time as short as 10 minutes. This trend marks a continuation of elevated UV levels observed since March, highlighting the region's consistent vulnerability to intense sun exposure during the warmer months. As autumn approaches, the UV Index slightly decreases in October, but the peril of sunburn remains a concern. Residents and visitors alike should prioritize sun protection strategies throughout September to mitigate risks associated with such high UV ratings. For detailed information and tips, check out the Hermosillo UV Index.

Maximum UV Index Levels in Hermosillo for September

The chart shows the monthly maximum UV Index (UVI) for Hermosillo in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec10121414141414131413109
Data source: Hermosillo September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Hermosillo

September in Hermosillo, Mexico, basks in a delightful 267 hours of sunshine, contributing to a warm transition into autumn. While the sun shines less than in the vibrant summer months—such as July, with its peak of 303 hours—September still offers ample bright days for outdoor adventures. The pattern reveals a gradual decline in sunlight from the summer peak, starting in June with 259 hours, but September’s rays continue to illuminate the city, making it a charming time for visitors and locals alike. As the year progresses, the hours of sunshine rebound to 304 hours in November and further increase to 317 hours in December, setting the stage for a sun-filled holiday season.

Monthly Sunshine Duration in Hermosillo: September Highlighted

The September sunshine duration represents the total number of hours Hermosillo experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec255h287h323h314h308h259h303h285h267h268h304h317h
Data source: Hermosillo September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hermosillo During September

In Hermosillo, Mexico, sunny days tend to dwindle as summer draws to a close, with September showcasing a mere 13% chance of sun. This marks a significant decline compared to the earlier months of the year where the sun shines brightly—January boasts a 65% chance, and even February reaches 78%. As we move from the intense heat of June and July, which both see less than 20% sunshine, September continues the trend of diminishing sunny weather, suggesting a shift towards the cooler and more cloud-covered months ahead. By the time October arrives, the likelihood of clear skies begins to creep up again, reflecting the seasonal transitions characteristic of this region.

Percentage of Sunny Days in September in Hermosillo

The chart illustrates the percentage of sunny days in Hermosillo throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Hermosillo experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec65%78%64%44%26%8%18%12%13%28%55%74%
Data source: Hermosillo September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hermosillo in September

As September arrives in Hermosillo, Mexico, the city enjoys a generous 12 hours of daylight, maintaining the trend established from March through August. This steady illumination not only enhances the vibrant lifestyle of locals but also marks a seamless transition into the autumn months. While daylight begins to wane in October, the consistency of 12 hours during September encourages outdoor activities and communal gatherings, showcasing the region's sunshine-filled days before the cooler months set in. As the year progresses, Hermosillo's daylight pattern reveals a rhythmic cycle, allowing residents to bask in plenty of daylight for most of the warm season, nurturing both spirits and social connections.

Average Daylight Hours in Hermosillo for September

The chart illustrates the variation in daylight duration in Hermosillo throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 20m11h 38m12h 3m12h 28m12h 49m12h 59m12h 53m12h 35m12h 11m11h 46m11h 25m11h 14m
Data source: Hermosillo daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Hermosillo

As September unfolds in Hermosillo, Mexico, the city experiences a gentle lull in the wind, with an average speed of only 1.1 m/s (2 mph). This tranquil breeze mirrors the overall trend seen throughout the late summer months, where wind speeds are consistently low, particularly from May to September. In fact, post-July, the winds hardly change, maintaining a whispering presence that offers a refreshing contrast to the region's warm climate. As we transition into October, the winds seem to settle even further, embodying the calm before the shift in seasons. This pattern not only highlights the serene ambiance of September but also sets the stage for the cooler, more dynamic winds that will eventually accompany the autumn months.

Average September Wind Speed in Hermosillo

The chart displays monthly wind speed patterns in Hermosillo, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec1.41.51.41.31.11.11.11.11.1 m/s1.01.31.3
Data source: Hermosillo September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Hermosillo Compares to Other Months

The weather in Hermosillo changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Hermosillo and find detailed weather information for every month.

In September, the weather is characterized by warm temperatures, with an average of 24°C (75°F) and highs reaching up to 31°C (88°F). However, this month also brings significant rainfall, with 683 mm (26.9 in) of precipitation over 29 days, resulting in high humidity levels of 82%. In contrast, January sees milder conditions, with a lower average temperature of 23°C (73°F), a minimum of 13°C (56°F), and highs peaking at 32°C (91°F). This month experiences drastically reduced rainfall, with only 27 mm (1.0 in) of precipitation and just 6 rainy days, leading to lower humidity at 76%. For more detailed information, check out Hermosillo weather in January.

In September, the weather tends to be quite humid and rainy, with temperatures ranging from a mild 17°C (63°F) at night to a warm 31°C (88°F) during the day, accompanied by an impressive 683 mm (26.9 in) of precipitation over 29 days. In contrast, February offers a more comfortable climate, with slightly cooler temperatures, featuring a minimum of 14°C (57°F) and a maximum of 33°C (91°F), but with significantly less rainfall at just 15 mm (0.6 in) over only 3 days. Additionally, February's humidity is more manageable at 68%, making it a more pleasant time to enjoy outdoor activities. For more detailed information, you can check Hermosillo weather in February.

In comparing the weather of September and March, September presents a notably warmer and wetter climate. With temperatures ranging from a minimum of 17°C (63°F) to a maximum of 31°C (88°F), it averages around 24°C (75°F) while experiencing significant rainfall of 683 mm (26.9 in) over 29 days, contributing to a high humidity level of 82%. In contrast, March showcases slightly cooler temperatures with a minimum of 15°C (60°F) and a maximum of 32°C (91°F), maintaining the same average of 24°C (76°F). The precipitation in March is significantly lower, at just 38 mm (1.5 in) across 9 days, and the humidity drops to a more comfortable 59%. For more detailed insights, you can visit Hermosillo weather in March.

When comparing the weather in September and April, a few striking differences emerge. September tends to be relatively warm, with an average temperature of 24°C (75°F) and daytime highs reaching up to 31°C (88°F). However, it also brings a significant amount of rainfall, accumulating 683 mm (26.9 in) over 29 days, accompanied by high humidity levels of 82%. In contrast, April offers slightly warmer conditions with a maximum temperature of 34°C (94°F) and an average of 25°C (78°F), but experiences much less precipitation, totaling only 120 mm (4.7 in) over 17 days and a more comfortable humidity level of 57%. For more details on April's weather, you can check Hermosillo weather in April.

September and May showcase distinctly different weather patterns. In September, temperatures range from a minimum of 17°C (63°F) to a maximum of 31°C (88°F), with an average of 24°C (75°F). This month experiences significant rainfall, accumulating 683 mm (26.9 in) over 29 days, resulting in high humidity levels at 82%. Conversely, May features slightly warmer temperatures with a minimum of 18°C (65°F) and a maximum of 34°C (93°F), alongside an average of 25°C (77°F). Precipitation in May is lower, totaling 533 mm (21.0 in) across 30 days, and the humidity is more comfortable at 65%. For more details on May weather, you can check Hermosillo weather in May.

In comparing the weather of September and June, we can observe some notable similarities and differences. Both months feature an average temperature of around 24°C (75°F), but September tends to have a slightly cooler minimum temperature of 17°C (63°F) compared to June's minimum of 18°C (64°F). On the other hand, June reaches a slightly higher maximum temperature of 32°C (90°F) compared to September's 31°C (88°F).

In terms of precipitation, September is significantly wetter, with 683 mm (26.9 in) of rain over 29 days, contrasted with June's 553 mm (21.8 in) over the same number of days. This results in a much higher humidity level in September at 82%, while June maintains a more comfortable 66%. Overall, while both months share warm temperatures, September is characterized by higher rainfall and humidity, making it feel quite different from June. For more detailed insights on June weather, you can visit Hermosillo weather in June.

When comparing the weather in September and July, both months feature similar temperature ranges, with minimums around 17°C (63°F), average temperatures near 24°C (75°F), and maximums reaching 31°C (88°F in September and 89°F in July). However, September is notably wetter, with a significant increase in precipitation to 683 mm (26.9 in) over 29 days, compared to July's 460 mm (18.1 in) over 31 days. Additionally, September experiences higher humidity levels at 82%, while July maintains a lower humidity of 75%. For a more detailed look at July weather, you can explore Hermosillo weather in July.

In comparing the weather of September and August, both months exhibit similar temperature ranges with minimums around 17°C (63°F) and 17°C (64°F) respectively, and average temperatures close to 24°C (75°F) in September and 24°C (76°F) in August. However, August experiences a slightly higher maximum temperature of 32°C (90°F) compared to September's peak of 31°C (88°F). Precipitation levels differ notably; September sees a significant increase with 683 mm (26.9 in) spread over 29 days, while August has 590 mm (23.2 in) over 30 days. Both months maintain a constant humidity of 82%, contributing to a tropical feel. For more detailed information, you can refer to Hermosillo weather in August.

Comparing the weather in September and October reveals some intriguing similarities and slight differences. Both months feature similar temperature ranges, with September recording a minimum of 17°C (63°F) and October slightly cooler at 16°C (62°F). Average and maximum temperatures remain steady at 24°C (75°F) and 31°C (88°F) respectively for both months. Precipitation is slightly lower in October at 658 mm (25.9 in) compared to 683 mm (26.9 in) in September, though both months experience a high number of rainy days—29 in September and 30 in October. Humidity remains nearly constant, with September at 82% and October increasing slightly to 83%. For more detailed insights, you can check out the Hermosillo weather in October.

In comparing the weather patterns of September and November, it is evident that both months exhibit warm temperatures, yet they differ in various aspects. September experiences a higher average temperature of 24°C (75°F) with a maximum reaching 31°C (88°F), while November has a slightly cooler average of 23°C (74°F) but can still peak at 32°C (89°F). Precipitation levels also show a significant contrast, as September receives 683 mm (26.9 in) of rainfall over 29 days, making it much wetter compared to November's 276 mm (10.9 in) over 24 days. Additionally, humidity levels are quite similar, with September at 82% and November slightly lower at 80%. For more detailed information, you can check Hermosillo weather in November.

In September, the weather is warmer and more humid, with average temperatures ranging from a minimum of 17°C (63°F) to a maximum of 31°C (88°F). This month experiences substantial rainfall, with 683 mm (26.9 in) of precipitation spread over 29 days, resulting in a humidity level of 82%. In contrast, December sees slightly cooler temperatures, with a minimum of 15°C (58°F) and a maximum of 30°C (87°F), accompanied by much less rain, totaling only 48 mm (1.9 in) over just 9 days. The humidity in December also drops to a more comfortable 76%. For more detailed information, check out Hermosillo weather in December.

Compare Hermosillo's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Hermosillo

As September unfolds in Hermosillo, the weather showcases a unique blend of warmth and moisture that sets it apart from the preceding months. With maximum temperatures reaching a pleasant 31°C (88°F), residents experience a comfortable ambiance, although the average temperature hovers around 24°C (75°F), serving as a gentle reminder of summer's end. The distinct characteristic of high humidity at 82%, coupled with nearly 30 days of substantial rainfall totaling 683 mm (26.9 in), transforms the landscape and adds vibrancy to the season. This combination of warm days and increased precipitation distinguishes September from the typically drier and hotter months, making it a unique time to experience the lush beauty of Hermosillo. For more insights on what to expect throughout the year, visit Hermosillo Climate.