Last updated: February 24, 2025
Experience the vibrant September weather in Phoenix, United States, where the sun reigns supreme with a maximum temperature soaring to a sizzling 45°C (113°F). The month presents a warm average of 32°C (89°F), providing a delightful setting for outdoor adventures. As the heat subsides in the evenings, temperatures can drop to a refreshing minimum of 13°C (56°F). Though the city enjoys ample sunshine, it also sees occasional precipitation, with 27 mm (1.1 in) of rain over just 3 days, highlighting the balance between dry heat and brief, welcome showers. At a humidity level of 64%, the air carries a hint of moisture, further enriching the unique desert climate of this dynamic city.
In September, Phoenix experiences a noticeable transition in temperatures as summer begins to wane. With minimums around 13°C (56°F) and average highs reaching a balmy 32°C (89°F), the city still embraces warmth, but with less intensity than the peak of summer. The maximum temperatures can soar to a scorching 45°C (113°F), showcasing the tail end of the hot season. As the month progresses, there's a subtle hint of relief from the relentless heat, particularly as average readings start to dip, paving the way for the more manageable fall months ahead. This balance of warmth combined with gradually cooling nights makes September an enticing time to experience the vibrant energy of Phoenix.
In September, Phoenix experiences a moderate dip in precipitation, recording 27 mm (1.1 in) over just three days of rain. This amount marks a slight decrease from the wetter months of July and August, which together see nearly 76 mm combined, reflecting the seasonal transition as summer fades. Interestingly, September's rainfall is comparable to earlier months in the year, with January and October showing similar totals. While the monsoon season begins to retreat, the precipitation in September helps to maintain the desert's vibrant flora, hinting at the cyclical nature of rainfall in this region. As the cooler months approach, the landscape remains refreshed yet anticipates the gradual return to drier days ahead.
In September, Phoenix experiences a notable shift in humidity levels, rising to 64% after the drier summer months. This increase reflects a transition towards the wetter fall season, as the city moves away from June and July's remarkably low humidity of 33% and 34%. While September's humidity is still relatively low compared to the winter months—such as January and December, where humidity peaks at 76% and 82% respectively—it marks a significant uptick that indicates the onset of more moisture in the atmosphere. As temperatures begin to cool, the return of humidity enhances the overall weather experience, foreshadowing the lush, invigorating conditions of the coming months.
In September, Phoenix experiences a very high UV Index of 10, indicating a significant risk of harm from unprotected sun exposure. As summer wanes, this index remains consistent with the extreme values seen in the heart of summer, where the burn time was as short as 10 minutes in June through August. The transition into fall sees a slight easing, yet the need for sun protection remains critical; with a burn time of 15 minutes, it's essential to take precautions. This trend reflects the city’s desert climate, where UV radiation remains a consistent concern even as temperatures begin to cool. For more detailed information, check out Phoenix UV Index.
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September in Phoenix offers a delightful transition into fall, marked by approximately 315 hours of sunshine. This month continues the trend of abundant sunlight, following June's peak of 375 hours and a busy summer brimming with sunshine. As temperatures begin to moderate, the city often sees a slight dip in sunshine compared to the intense summer months, yet it still benefits from more than 10 hours of sunshine per day. With daylight gradually waning, outdoor enthusiasts can relish the warm, golden skies and perfect conditions for exploring the city's stunning landscapes. The sun's steady presence throughout the year sets the stage for September's inviting charm, making it an ideal time for both residents and visitors to enjoy the beautiful desert scenery.
As summer transitions into fall, September in Phoenix boasts a commendable 70% chance of sunny weather, making it an ideal time for outdoor activities. This month sees a slight dip in sunshine compared to the preceding May (90%) and June (72%), yet it remains brighter than the sweltering July (36%) and more overcast August (59%). Interestingly, the sun-soaked momentum continues into the early autumn months, with October rebounding to 76% sunshine, indicating that while September might usher in the onset of autumn, it still retains a generous share of sunny days perfect for enjoying the desert landscape.
As September arrives in Phoenix, daylight begins its gentle descent, offering approximately 12 hours of sunlight. This month marks a transition from the peak summer days, which bask in the brilliance of 14 hours of daylight during June and July. Following the vibrant summers, August's daylight dips slightly, and as fall approaches, September's sunlight reflects the gradual shift toward shorter days, reminiscent of the 11 hours seen in October. This rhythmic pattern highlights Phoenix's diverse seasonal tapestry, where sun-soaked days gradually give way to the cozy embrace of autumn, inviting residents to relish the changing ambiance.
As September rolls into Phoenix, the gentle whispers of the wind signal a noticeable shift in the transition from summer's swelter to autumn's embrace. With an average wind speed of 1.8 m/s (4 mph), September marks a decline from the summer's peak breezes, with July and August averaging just slightly higher. This seasonal lull in wind activity highlights the desert's characteristic stillness as the intense heat recedes. Despite this subtle dip, September's mild breezes provide a refreshing contrast to the preceding months, gently nudging residents towards the upcoming cooler days of October and beyond, where wind speeds begin to pick up again.
The weather in Phoenix 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 Phoenix and find detailed weather information for every month.
September and January present striking contrasts in weather. In September, temperatures soar with a minimum of 13°C (56°F) and an average of 32°C (89°F), peaking at a scorching 45°C (113°F). The month sees light precipitation of 27 mm (1.1 in) over just three days, accompanied by moderate humidity at 64%. In contrast, January offers much cooler conditions, with temperatures ranging from a minimum of -1°C (30°F) to an average of 12°C (54°F) and a maximum of 29°C (84°F). Despite slightly lower precipitation at 25 mm (1.0 in) over four days, January's humidity is higher at 76%. For more details on the winter climate, check out Phoenix weather in January.
September and February in Phoenix present a stark contrast in weather. September typically boasts much higher temperatures, with averages around 32°C (89°F) and maximums soaring up to 45°C (113°F), while February offers a cooler climate with an average temperature of 14°C (57°F) and a maximum of 29°C (84°F). Additionally, February experiences higher humidity levels at 79%, compared to September's 64%, providing a more damp ambiance. Although both months see precipitation on about three days, February has slightly more rainfall at 37 mm (1.4 in) compared to September's 27 mm (1.1 in). For more information on Phoenix's February weather, check out Phoenix weather in February.
September weather tends to be significantly hotter than March, with average temperatures reaching a high of 32°C (89°F) compared to March's average of 18°C (65°F). The maximum temperature in September can soar up to 45°C (113°F), while March sees a peak of 35°C (95°F). Both months have similar levels of precipitation, with September recording 27 mm (1.1 in) and March slightly higher at 29 mm (1.2 in), yet both typically experience rainfall on three days. Humidity levels are comparable, with September at 64% and March at 67%. For more detailed insights, you can check Phoenix weather in March.
In comparing the weather between September and April, we see a notable contrast in temperatures and precipitation. September tends to be much hotter, with average highs reaching 32°C (89°F) and maximum temperatures soaring up to 45°C (113°F). In contrast, April offers milder conditions, with an average temperature of 24°C (75°F) and maximums peaking at 39°C (103°F). Additionally, September experiences more humidity at 64% and receives more precipitation (27 mm) over three days, while April is much drier, with only 1 mm of rain throughout the month and no rainy days reported. For more details about April weather, you can check out Phoenix weather in April.
When comparing the weather in September and May, a few distinct differences emerge. September generally experiences warmer conditions, with average temperatures around 32°C (89°F) and maximums reaching up to 45°C (113°F), while May has milder temperatures averaging 28°C (82°F) and peaking at 43°C (109°F). Additionally, September tends to be more humid, with humidity levels at 64% compared to May's lower 40%. Rainfall also varies significantly, as September sees about 27 mm (1.1 in) of precipitation over three days, whereas May is notably drier with just 2 mm (0.1 in) and no precipitation days. For detailed information about Phoenix weather, you can visit Phoenix weather in May.
In September, temperatures in Phoenix typically range from a minimum of 13°C (56°F) to a maximum of 45°C (113°F), with an average of 32°C (89°F). This month experiences some precipitation, with about 27 mm (1.1 in) over 3 days, and humidity levels are quite high at 64%. In contrast, June is generally hotter, with temperatures ranging from a minimum of 19°C (66°F) to a scorching maximum of 48°C (119°F), and an average of 34°C (93°F). Notably, June sees virtually no rainfall, with only 2 mm (0.1 in) over 0 days, resulting in a much lower humidity level of 33%. For more details, check Phoenix weather in June.
When comparing the weather in September and July, we find notable differences in temperature and humidity. In July, temperatures range from a minimum of 23°C (74°F) to a scorching maximum of 47°C (118°F), with an average temperature of 35°C (95°F). This month also experiences higher humidity levels at 34% and more precipitation, totaling 37 mm (1.4 in) over roughly 6 days. In contrast, September features a broader temperature range with a minimum of 13°C (56°F) and a maximum of 45°C (113°F), resulting in an average temperature of 32°C (89°F). September is relatively drier, receiving just 27 mm (1.1 in) of precipitation over 3 days, while the humidity is considerably higher at 64%. For more detailed information about July weather in Phoenix, visit Phoenix weather in July.
In comparing the weather between September and August, September generally experiences cooler minimum temperatures, averaging 13°C (56°F) compared to August's warmer minimum of 22°C (73°F). The average temperature in September settles at 32°C (89°F), while August is slightly hotter at 35°C (95°F). August also records higher maximum temperatures, peaking at 47°C (116°F), whereas September's maximum reaches 45°C (113°F).
Precipitation in August is more substantial, with 39 mm (1.5 in) recorded over 5 days, compared to September's 27 mm (1.1 in) spread over just 3 days. Notably, humidity levels are higher in September at 64%, contrasting with August's 48% humidity. For a detailed look at August conditions, check out Phoenix weather in August.
September and October in Phoenix show a notable shift in weather conditions. September experiences high temperatures, with an average of 32°C (89°F) and peaks reaching up to 45°C (113°F), while October sees a drop in both minimum and average temperatures, down to 7°C (45°F) and 24°C (76°F) respectively. Precipitation levels remain similar, with September recording 27 mm (1.1 in) over three days compared to October’s 26 mm (1.0 in) over just two days. Humidity also sees a slight increase from September’s 64% to October’s 67%. For more detailed insights, check out Phoenix weather in October.
September in Phoenix is characterized by high temperatures, with average highs reaching 32°C (89°F) and occasional peaks of up to 45°C (113°F). The weather is relatively humid, with a humidity level of 64% and an average of 27 mm (1.1 in) of precipitation spread over three days. In contrast, November brings much cooler temperatures, with an average high of 18°C (66°F) and a maximum of 36°C (97°F). The shift towards fall is marked by lower humidity at 77% and minimal rainfall, averaging just 21 mm (0.8 in) over only one day. For more detailed insights, check out Phoenix weather in November.
In September, the weather is characterized by a significant heat wave, with average temperatures soaring to 32°C (89°F) and maximums reaching as high as 45°C (113°F). The month sees relatively low precipitation of 27 mm (1.1 in) over just three days, accompanied by a moderate humidity level of 64%. In contrast, December brings a dramatic shift in climate, with temperatures dropping to a minimum of 0°C (32°F) and an average of 13°C (55°F), peaking at 28°C (83°F). The month experiences slightly less rainfall at 23 mm (0.9 in), but with increased humidity at 82% and precipitation occurring over four days. This transition highlights the stark contrast between the scorching summer heat of September and the cooler, more humid conditions of December, as detailed in more depth at Phoenix weather in December.
As summer transitions to autumn, September in Phoenix brings a noticeable shift in weather compared to the sweltering heat of the preceding months. With average temperatures settling around a more manageable 32°C (89°F), the intense highs of 45°C (113°F) become less frequent, providing a welcome reprieve. Additionally, the city experiences a slight increase in humidity at 64%, contributing to a more muggy feel on certain days. While precipitation becomes a rare guest, with only about 27 mm (1.1 in) over a mere 3 days, this month often hints at the arrival of fall with the potential for brief thunderstorms. To explore more about how September fits into the broader patterns, check out Phoenix Climate.