Last updated: February 24, 2025
In September, Tucson, United States experiences a dynamic shift in weather, characterized by a maximum temperature peaking at an impressive 41°C (106°F). The month averages a comfortable 28°C (83°F), providing a warm respite as the summer heat begins to wane. Nighttime offers a cooler retreat, with minimum temperatures dipping to 13°C (56°F). Rainfall is modest, with 27 mm (1.1 in) recorded over just three days, contributing to a mild humidity level of 64%. This combination of warmth and occasional moisture creates an inviting atmosphere for outdoor activities, making September a vibrant time to explore Tucson's natural beauty.
As September rolls into Tucson, the desert city begins to transition from the sweltering summer heat to more bearable temperatures. With a minimum of 13°C (56°F) and an average of 28°C (83°F), the month offers a noticeable drop from the stifling highs experienced in August. While the maximum temperature still reaches a toasty 41°C (106°F), the cooler evenings provide a refreshing respite. This month marks a shift toward autumn, as daytime warmth continues to blend with cooler nights, inviting both locals and visitors to enjoy outdoor activities before the more significant chill of October sets in.
In September, Tucson receives an average of 27 mm (1.1 in) of precipitation, typically spread over about 3 days. This marks a slight increase from the drier months of the year, such as April and May, which barely register any rainfall. Interestingly, September's rainfall is a continuation of the monsoon season, following the wetter months of July and August. While July remains the wettest month with 54 mm (2.1 in), September’s precipitation helps sustain the greenery that blossoms during the summer rains. As the city transitions into the cooler autumn months, this relatively modest rainfall contributes to Tucson’s unique desert landscape, balancing the arid conditions experienced in the winter months ahead.
In September, Tucson experiences a notable increase in humidity, rising to 64% as summer begins to yield to autumn. This marks a shift from the dry spell of the summer months—where humidity dipped as low as 33% in June and July—ushering in a more comfortable atmosphere. As the desert heat starts to wane, the weather transitions into a moderate phase, reflected in the 48% humidity observed in August. Going forward, September's humidity prior hints at the approaching wetter months, with levels gradually climbing to 67% in October and peaking in the winter, reaffirming the cyclical nature of Tucson's climate throughout the year.
In September, Tucson experiences an UV Index of 11, indicating an extreme exposure category that necessitates caution and protection from harmful sun rays. This month continues the trend of heightened UV levels typical during the late summer, aligning closely with August when the UV Index also peaked at 11. Interestingly, this extreme rating has persisted through the summer months, starting from May and holding steady until September. With a burn time of just 10 minutes, residents and visitors should prioritize sunscreen and protective clothing while enjoying the outdoors. As the year progresses into October, we can expect a decline in UV strength to 8, signaling a gradual shift toward safer sun exposure. For more detailed information, visit Tucson UV Index.
UV Risk Categories
As summer gracefully transitions into fall, September in Tucson continues to bask in the warmth of the sun, boasting an impressive 312 hours of sunshine. This month follows the peak of sunlight seen in May and June, where residents enjoyed a remarkable 371 hours of radiant days. While the days gradually shorten with the arrival of autumn, September's sun still shines brightly, slightly less than the summer's heights but significantly more than the dimmer months that follow. As the year unfolds, one can observe how Tucson's climate transforms, yet September retains a vibrant glow, making it a perfect time for outdoor adventures and late-summer gatherings under the fading light.
In September, Tucson typically enjoys a 66% chance of sunny weather, making it a pleasant transition from the sweltering summer months. This likelihood marks a slight decrease from the previous months, with May's peak sunshine probability of 88%, yet it remains quite favorable when compared to the gloomy monsoon July, which plunges to a mere 34%. As the season shifts from summer to fall, the sunny outlook begins to stabilize, paving the way for October's inviting 81% chance of sunshine. Overall, while September heralds the end of summer, it still offers ample opportunities to bask in the warm Arizona sun before the cooler months set in.
As summer transitions to fall in Tucson, September marks a gentle shift in daylight duration, offering 12 hours of sunlight. Following the peak of 14 hours in June, daylight gradually tapers, reflecting nature's rhythm. This month serves as a bridge between the long, sunny days of summer and the shorter, cooler days of autumn, as the daylight hours decrease in a graceful decline. With 12 hours of daylight in September, residents can still relish ample sunshine while anticipating the cozy embrace of October, which brings another reduction to 11 hours. This trend highlights Tucson's unique climatic dance, where each month brings its own charm, and seasonal changes are felt vividly.
As September arrives in Tucson, the wind begins to whisper softly at an average speed of 2.1 m/s (5 mph), mirroring the gentle breezes of July and August. As summer wanes, these light winds signal a transition, with a notable dip from the stronger gusts of earlier months that reached up to 3.3 m/s (7 mph) during the spring. This trend of decreasing wind speeds persists into autumn, foreshadowing a gradual shift towards October, where winds pick up slightly to 2.6 m/s (6 mph). The consistent mildness in September creates a serene atmosphere, inviting both residents and visitors to bask in the warmth while the gentle winds offer a refreshing touch, perfectly encapsulating the essence of an early fall in the desert.
The weather in Tucson 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 Tucson and find detailed weather information for every month.
September and January present starkly contrasting weather conditions. In September, temperatures soar with a minimum of 13°C (56°F) and an average of 28°C (83°F), reaching highs of 41°C (106°F). The month experiences a moderate amount of precipitation at 27 mm (1.1 in) over three days, with humidity around 64%. In contrast, January's temperatures are much cooler, with a minimum of -1°C (30°F), an average of 11°C (53°F), and a maximum of 25°C (77°F). The winter month sees slightly less precipitation at 23 mm (0.9 in), also over three days, but the humidity is higher at 76%. For more information on the weather in Tucson during January, you can check out Tucson weather in January.
September brings warm temperatures to the region, with averages reaching a hot 28°C (83°F) and maximums soaring up to 41°C (106°F), while only experiencing minimal precipitation of 27 mm over about three days. In contrast, February presents a much cooler climate, with average temperatures dropping to 13°C (55°F) and nightly lows of -3°C (27°F). This month sees slightly more rainfall, totaling 34 mm across four days, and higher humidity at 79%. For more details on February's weather, you can visit Tucson weather in February.
In comparing the weather between September and March, there is a striking contrast in temperatures and overall climate characteristics. September typically enjoys warmer conditions, with average temperatures reaching up to 28°C (83°F) and highs peaking at 41°C (106°F), alongside a relatively low precipitation of 27 mm (1.1 in) over 3 days. In contrast, March presents a much cooler climate, with temperatures averaging around 16°C (62°F) and maximums of 33°C (92°F). Additionally, March experiences less rainfall, totaling 15 mm (0.6 in) over the same three-day span. Humidity levels are slightly higher in March at 67%, compared to September's 64%. For a deeper look at how Tucson weather shifts in March, check out Tucson weather in March.
In comparing September and April weather, September tends to be significantly warmer, with average temperatures around 28°C (83°F) and highs reaching up to 41°C (106°F). In contrast, April features milder conditions, averaging 22°C (71°F) with maximum temperatures of 37°C (98°F). Additionally, September experiences some precipitation, with 27 mm (1.1 in) over three days, while April remains quite dry, receiving only 2 mm (0.1 in) and no recorded rainy days. Humidity levels are also higher in September at 64%, compared to 55% in April, contributing to the overall difference in comfort between these two months. For more details, you can check Tucson weather in April.
September and May exhibit notable differences in weather patterns. In September, temperatures range from a minimum of 13°C (56°F) to a scorching maximum of 41°C (106°F), with an average temperature of 28°C (83°F). This month also experiences relatively higher humidity at 64% and some rainfall, totaling 27 mm (1.1 in) over about three days. In contrast, May offers a milder climate, with temperatures ranging from a minimum of 9°C (48°F) to a maximum of 40°C (104°F) and an average of 25°C (78°F). Additionally, May enjoys lower humidity at 40% and minimal precipitation of only 3 mm (0.1 in) over just one day, making it a drier month. For more detailed weather insights, check Tucson weather in May.
September and June exhibit distinct weather patterns, highlighting the transition from the intense summer heat to slightly milder conditions. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 41°C (106°F), with an average of 28°C (83°F) and occasional rainfall, totaling 27 mm (1.1 in) over three days. In contrast, June is hotter overall, with minimums around 17°C (62°F) and maximums peaking at 44°C (111°F), averaging 31°C (88°F) and experiencing virtually no precipitation. The humidity also varies significantly, with September being more humid at 64%, compared to June's drier humidity level of 33%. For more details about Tucson's weather during June, you can visit Tucson weather in June.
When comparing the weather in September and July, September tends to have a broader temperature range, with minimums of 13°C (56°F) and maximums reaching up to 41°C (106°F). Its average temperature is slightly lower at 28°C (83°F) compared to July’s higher average of 31°C (88°F). In terms of precipitation, September sees 27 mm (1.1 in) over just three days, while July has significantly more rainfall at 54 mm (2.1 in) spread across ten days. Additionally, September's humidity averages around 64%, making it feel more humid than July's lower average of 34%. For more details on July weather in Tucson, you can check out Tucson weather in July.
In comparing the weather of September and August, September generally exhibits a wider temperature range, with minimum temperatures dipping to 13°C (56°F) compared to August's more moderate minimum of 20°C (69°F). While the average temperature in August is slightly higher at 31°C (87°F), September still reaches impressive maximums of 41°C (106°F). Precipitation in September is lower at 27 mm (1.1 in) over just 3 days, in contrast to August's 35 mm (1.4 in) spread across 8 days, and the humidity level in September is noticeably higher at 64% compared to 48% in August. For more detailed insights into August weather patterns, check out Tucson weather in August.
September and October present a notable contrast in weather patterns. In September, temperatures are significantly warmer, with minimums around 13°C (56°F) and an average high of 28°C (83°F), reaching up to 41°C (106°F) on the hottest days. The month experiences more precipitation with 27 mm (1.1 in) over three days and a humidity level of 64%. In contrast, October sees a drop in temperatures, featuring a minimum of 4°C (39°F) and an average of 23°C (73°F), with maximums reaching 38°C (100°F). It also has less precipitation, totaling only 10 mm (0.4 in) over two days, while humidity increases slightly to 67%. For more detailed information, you can check Tucson weather in October.
Comparing the weather in September and November reveals a significant transition as the seasons change. In September, temperatures soar, with daily averages around 28°C (83°F) and extremes reaching up to 41°C (106°F). The humidity sits at a comfortable 64%, and the month sees some rain, with a total precipitation of 27 mm (1.1 in) over three days. In contrast, November brings a notable drop in temperatures, with averages cooling to 17°C (64°F) and maximums of 33°C (91°F). The humidity increases to 77%, but the month is relatively dry, receiving only 14 mm (0.6 in) of precipitation across just one day. For more detailed insights, check out Tucson weather in November.
September and December present a striking contrast in weather patterns. In September, temperatures can soar with a minimum of 13°C (56°F) and an average high reaching up to 41°C (106°F), accompanied by relatively low humidity levels of 64%. Precipitation is minimal, falling on about three days. In contrast, December experiences much cooler temperatures, with lows plummeting to -2°C (29°F) and average highs around 27°C (80°F), while humidity rises significantly to 82%. While both months see similar amounts of precipitation (27 mm), December tends to be wetter over a slightly longer duration, with rainfall on four days. For more details on the peculiarities of December weather, you can visit Tucson weather in December.
As September rolls into Tucson, the desert climate begins to shift, offering a blend of warm days and cool evenings. While temperatures can soar in the afternoons, averaging a pleasant 28°C, the nights provide a refreshing break with cooler lows, making it an ideal time for outdoor activities. With only a few rainy days sprinkled throughout the month and a moderate humidity level, September's weather stands in stark contrast to the blistering heat of summer while still maintaining a taste of warmth. For a deeper dive into Tucson's unique weather patterns throughout the year, check out Tucson Climate.