September Weather in Hermosillo, Mexico

Last updated: April 22, 2025

September in Hermosillo, Mexico, showcases a striking contrast in temperatures, with maximums reaching a blistering 48°C (120°F) and an average of 32°C (90°F). The nights offer a welcome respite, dipping to a minimum of 16°C (61°F). During this month, the region experiences limited rainfall, accumulating only 18 mm (0.7 in) over approximately three days, contributing to a moderate humidity level of 52%. This blend of warmth and sporadic moisture creates a unique climate, perfect for exploring the vibrant surroundings while staying hydrated.

September Temperature in Hermosillo

In Hermosillo, Mexico, September brings a notable transition in temperatures as the summer heat begins to wane. With minimums around 16°C (61°F) and maximums soaring to 48°C (120°F), the weather still retains a summerlike intensity, showcasing the region's typically extreme conditions. The average temperature settles at a comfortable 32°C (90°F), making it a hot month, yet slightly less oppressive compared to the scorching July and August. As the month progresses, the cooler nights offer a refreshing contrast to the day’s warmth, hinting at the approaching autumn. This dynamic shift creates a unique atmosphere, perfect for both locals and visitors to enjoy the vibrant landscapes of this desert city.

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.
JanFebMarAprMayJunJulAugSepOctNovDec596168778290969690786858
Data source: Temperature data for Hermosillo generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Hermosillo

In September, Hermosillo experiences a notable increase in precipitation, receiving 18 mm (0.7 in) of rain over three days. This uptick represents a peak for the year, as it outstrips the lower rainfall amounts seen in the summer months, like July and August, which register just 10 mm and 9 mm, respectively. Following a dry spell from June to May, where rain was nearly nonexistent, September’s rainfall marks a refreshing shift, signaling the tail end of the monsoon season. This trend of increased rainfall not only breathes life into the arid landscape but also sets the stage for what follows in the cooler months of October and November, where precipitation levels drop again to 6 mm and 6 mm respectively.

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.
JanFebMarAprMayJunJulAugSepOctNovDec8141732010918768
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hermosillo

As September rolls into Hermosillo, Mexico, the humidity levels begin to rise slightly, reaching 52%. This increase follows a trend of decreasing humidity from the peak months of late spring and early summer, when levels dipped to a low of 42% in August. Over the course of the year, Hermosillo experiences a clear transition: starting with relatively high humidity in the winter months, it ebbs down through the summer before gradually climbing again into autumn. The gradual return to higher humidity levels in September marks the start of a shift, hinting at the more moisture-laden months ahead, while still allowing for the lingering warmth associated with late summer.

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.
JanFebMarAprMayJunJulAugSepOctNovDec72%77%67%56%46%48%46%42%52%58%66%74%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hermosillo

As September arrives in Hermosillo, Mexico, the UV Index remains notably high at 10, classifying exposure as very high. This marks a slight decrease from the peak of 12 seen in July, yet it still demands attention as the burn time is set at only 15 minutes. The summer months have consistently showcased extreme UV levels, with May through August averaging an index of 11 to 12, making effective sun protection essential. As we transition into fall, the UV Index gradually begins to lower, hinting at the upcoming October index of 8. Visitors and residents alike should remain vigilant this September to safeguard their skin while enjoying the sun. For more details on UV levels throughout the year, 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.
JanFebMarAprMayJunJulAugSepOctNovDec469101111121110854
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

As the summer heat wanes in Hermosillo, September ushers in a gentle transition with an impressive 322 hours of sunshine. After the peak of May and June, which boast a remarkable 373 and 377 hours respectively, the daylight hours start to gradually decline yet remain generous compared to earlier months. The trend this month reflects a continuation of the vibrant sunshine that characterizes the warmer months, while hinting at the upcoming cooler days of October with its 304 hours. This sun-drenched month not only allows residents and visitors to savor lingering warm days but also sets the stage for a splendid autumn in the city.

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.
JanFebMarAprMayJunJulAugSepOctNovDec204h251h309h331h373h377h375h358h322h304h264h247h
Data source: Hermosillo September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hermosillo During September

Hermosillo, Mexico, experiences consistently sunny weather, particularly in September, where the chances of sun reach 84%. This trend follows a robust peak in sunny conditions during late spring and early summer, where May boasts the highest likelihood at 92%. As summer progresses, the chances of sunshine begin to decline, notably in July, dipping to 53%. However, September marks a resurgence in sunny days, reminiscent of the inviting conditions seen in earlier months. Overall, the month stands out as a transition into autumn, maintaining a solid promise of bright skies and warm weather, ideal for outdoor activities and exploration.

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.
JanFebMarAprMayJunJulAugSepOctNovDec71%73%83%82%93%77%54%84%84%81%74%62%
Data source: Hermosillo September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hermosillo in September

As summer gives way to autumn in Hermosillo, Mexico, September marks a notable shift in daylight hours. With an average of 12 hours of daylight, the month experiences a gentle decline from the peak 14 hours in June and July. This gradual transition highlights the region's warm climate, where longer days extend from spring through summer, before dipping slightly into fall. While September may bring a bit less sunlight than its summer predecessors, it still offers ample daylight, creating a perfect backdrop for outdoor activities in the early days of autumn. As October approaches, the retreat into shorter days continues, but September remains a vibrant blend of summer's light and the cool, inviting hints of fall.

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.
JanFebMarAprMayJunJulAugSepOctNovDec10h 16m11h 1m12h13h13h 50m14h 14m14h 1m13h 16m12h 19m11h 19m10h 27m10h 2m
Data source: Hermosillo daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Hermosillo

As summer transitions into fall, September in Hermosillo, Mexico, greets visitors with a gentle breeze, marked by an average wind speed of 2.3 m/s (5 mph). This is notably the calmest month of the year, following a trend of moderate winds that peak in July at 3.2 m/s (7 mph) before gradually tapering off. While the air is usually still, September's softness creates a tranquil atmosphere, inviting residents and travelers alike to savor the warm days and cooler evenings. The wind speeds then pick up slightly in October, hinting at the invigorating gusts that lay ahead as the region embraces autumn's arrival.

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.
JanFebMarAprMayJunJulAugSepOctNovDec2.73.12.92.92.72.83.22.82.3 m/s2.62.42.4
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 markedly hotter, with average temperatures soaring up to 32°C (90°F) and maximums reaching as high as 48°C (120°F). The humidity sits at a moderate 52%, and the month sees about 18 mm (0.7 in) of precipitation spread over three days. Conversely, January presents a much cooler climate, with an average temperature of 15°C (59°F) and a maximum of 30°C (86°F). The precipitation is lower, totaling 8 mm (0.3 in) over just one day, and humidity rises to 72%, contributing to a more refreshing atmosphere. For a detailed look at January's weather conditions, you can visit Hermosillo weather in January.

In September, temperatures in Hermosillo soar, with average highs reaching a sweltering 32°C (90°F) and extremes hitting 48°C (120°F). The month experiences relatively low humidity at 52% and minimal precipitation, averaging just 18 mm (0.7 in) over three days. In contrast, February offers a much cooler climate, with average highs around 16°C (62°F) and minimums dropping to 2°C (36°F). The humidity is noticeably higher at 77%, and precipitation is slightly less, totaling 14 mm (0.6 in) over two days. For a detailed look at February's weather in Hermosillo, check out Hermosillo weather in February.

In September, the weather is considerably warmer, with average temperatures soaring to around 32°C (90°F) and maximums reaching up to 48°C (120°F). This month experiences minimal precipitation of about 18 mm (0.7 in) over three days, alongside a relatively low humidity level of 52%. In contrast, March offers cooler conditions, with average temperatures of 20°C (68°F) and highs peaking at 37°C (98°F). It sees similar rainfall at 17 mm (0.7 in) but only over one day, accompanied by higher humidity at 67%. For more detailed insights, you can check Hermosillo weather in March.

In comparing the weather of September and April, September offers significantly warmer temperatures, with averages reaching up to 32°C (90°F) and maximums hitting a scorching 48°C (120°F). In contrast, April features milder conditions, with average temperatures around 25°C (77°F) and maximums of 43°C (109°F). Precipitation levels are also notably different, with September receiving 18 mm (0.7 in) over three days, whereas April enjoys dry weather with just 3 mm (0.1 in) and no rainy days, resulting in slightly higher humidity at 56%. For more details on April weather, check out Hermosillo weather in April.

September and May present contrasting weather patterns in terms of temperature and precipitation. September typically boasts higher temperatures, with minimums around 16°C (61°F) and averages reaching up to 32°C (90°F), while May starts slightly cooler, with minimums at 13°C (55°F) and averages of 28°C (82°F). Additionally, September experiences more humidity at 52% and some precipitation, averaging 18 mm (0.7 in) over three days, whereas May enjoys a dry spell with only 2 mm (0.1 in) of rain across the entire month, resulting in no rainy days. For more detailed insights on May weather, you can check this link: Hermosillo weather in May.

In comparing the weather between September and June, both months showcase similar average temperatures, hovering around 32°C (90°F). However, September experiences a slightly wider temperature range, with minimums dipping to 16°C (61°F) and maximums peaking at 48°C (120°F), while June starts at a higher minimum of 18°C (65°F) and reaches a maximum of 49°C (120°F). Notably, September has a total precipitation of 18 mm (0.7 in) over three days, indicating a more humid environment at 52%, whereas June is remarkably dry with no recorded precipitation and a lower humidity of 48%. For a detailed look at June's weather, check out Hermosillo weather in June.

In comparing the weather between September and July, September experiences slightly cooler temperatures with a minimum of 16°C (61°F) and an average of 32°C (90°F), while July boasts a higher minimum of 22°C (72°F) and an average of 35°C (96°F). Both months showcase extreme highs, reaching up to 48°C (120°F) in September and 48°C (119°F) in July. Precipitation is minimal in both months, with September receiving 18 mm (0.7 in) over 3 days and July having even less at 10 mm (0.4 in) over 2 days. Humidity levels are also slightly higher in September at 52%, compared to July’s 46%. For a more detailed look at July's weather, visit Hermosillo weather in July.

In comparing the weather between September and August, September offers a slightly cooler experience with an average temperature of 32°C (90°F), compared to August's hotter average of 36°C (96°F). While September has a minimum temperature of 16°C (61°F), August starts higher at 24°C (76°F). Both months see similar precipitation levels, but September has slightly more with 18 mm (0.7 in) over three days, compared to August's 9 mm (0.3 in) over the same duration. Interestingly, September also enjoys higher humidity at 52%, compared to August's 42%. For more detailed information, you can check Hermosillo weather in August.

September in Hermosillo typically features much warmer weather, with average temperatures soaring to around 32°C (90°F) and maximums reaching a blistering 48°C (120°F). The humidity sits at a comfortable 52%, and the month sees light precipitation of about 18 mm (0.7 in) over three days. In contrast, October ushers in a stark shift, where temperatures drop significantly, with averages around 25°C (78°F) and a maximum of 43°C (110°F). October also experiences notably less rainfall, just 6 mm (0.3 in) over a single day, while humidity rises slightly to 58%. For more detailed insights, you can explore Hermosillo weather in October.

September and November present contrasting weather patterns. In September, temperatures are significantly higher, with a minimum of 16°C (61°F) and averages soaring to 32°C (90°F), reaching up to a scorching maximum of 48°C (120°F). The month also sees some precipitation, averaging 18 mm (0.7 in) over three days, with humidity at a moderate 52%. Conversely, November brings a much cooler climate, with temperatures dipping to a minimum of 7°C (45°F) and an average of 20°C (68°F), peaking at 36°C (97°F). Rainfall is minimal in November, with only 6 mm (0.2 in) and no rainy days, accompanied by a higher humidity level of 66%. For more detailed information, check out Hermosillo weather in November.

September and December present stark contrasts in weather patterns. In September, temperatures soar, with average highs reaching 32°C (90°F) and extremes peaking at 48°C (120°F), alongside a moderate humidity of 52%. The month experiences a brief spell of precipitation, averaging about 18 mm (0.7 in) over three days. Conversely, December brings a cooler climate, with average temperatures dropping to 14°C (58°F), peaking at 28°C (84°F) and a notable decrease in rainfall to just 8 mm (0.3 in) over a single day. The humidity also rises to 74%, creating a distinct chill in the air. For a more in-depth look at December weather in Hermosillo, check out Hermosillo weather in December.

Compare Hermosillo's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Hermosillo

As September arrives in Hermosillo, the weather starts to shift, bringing a welcome respite from the sweltering summer heat. While temperatures still soar, averaging around 32°C, the nights offer cooler relief, dipping to a refreshing 16°C. This month also marks a transition, where moisture makes a brief appearance with an average of 18 mm of rainfall over just a few days, contrasting sharply with the dry conditions of prior months. As the humidity levels settle at 52%, the air feels noticeably different, setting the stage for the upcoming fall season. For a deeper insight into the climate variations throughout the year, be sure to check out Hermosillo Climate.