Last updated: August 27, 2025
September in Istanbul, Turkey offers a delightful transition from summer to autumn, with maximum temperatures reaching up to 32°C (90°F) and an average of 22°C (72°F), ensuring ideal conditions for exploring the city's rich history and vibrant culture. As temperatures begin to cool, the minimum drops to a refreshing 13°C (57°F). Expect occasional rain, as the month sees about 36 mm (1.4 in) of precipitation over roughly 6 days, contributing to a 60% humidity level that adds a touch of freshness to the air. Whether wandering through ancient bazaars or savoring local cuisine, September's weather sets the stage for an enjoyable experience in this enchanting metropolis.
In September, Istanbul experiences a delightful transition as summer begins to ebb. With average temperatures settling around 22°C (72°F), the city enjoys warm days characterized by a blend of comfortable warmth and cool evening breezes. The maximum temperature can reach a pleasing 32°C (90°F), allowing for plenty of outdoor activities, while the minimum dips to a mild 13°C (57°F) at night, perfect for cozy gatherings. This month marks a significant shift from the sweltering heat of August, inviting locals and tourists alike to explore the rich history and vibrant street life of this stunning city while basking in the pleasant climate. With September’s ideal weather, it’s no wonder that this month is a popular time to visit Istanbul.
September in Istanbul marks a subtle transition in the city's climate, as the summer heat begins to wane. With 36 mm (1.4 in) of precipitation spread over 6 days, the month sees a slight uptick in rainfall compared to the dry spell of August, which only recorded 18 mm (0.7 in). This increase hints at the approaching autumn and serves as a reminder of the city's characteristic variability. As summer retreats, the gradual return of precipitation lays the groundwork for the wetter months ahead, with October anticipated to bring even more rainfall at 56 mm (2.2 in) over 8 days. This trend underscores a notable shift in Istanbul's weather patterns, where September acts as a bridge between the aridness of summer and the invigorating rains of fall.
In September, Istanbul experiences a moderate humidity level of 60%, showcasing a slight uptick from the drier summer months of July and August, which see humidity drop to as low as 55%. This transition reflects the changing seasons as temperatures begin to cool, heralding the approach of autumn. While September stands out as more humid compared to peak summer, it is still significantly less humid than the heavy moisture of the winter months, highlighted by January and February, which consistently hover around 84%. This gradual decline from early winter’s dampness to the refreshing air of late summer paints a dynamic picture of Istanbul's climate, making September a pleasant time for both locals and visitors to explore the city amidst its shifting atmospheres.
As September rolls into Istanbul, the UV Index begins to taper off from the summer's peaks, settling at a high 7. This marks a transition from the intense very high levels experienced during the sweltering months of July and August, where burn times were alarmingly short at just 15 minutes. In September, you can bask in the sun a bit longer with a burn time of 25 minutes, but caution is still advised. The shift to a lower UV exposure is accompanied by the gradual onset of autumn, yet it serves as a reminder that sun safety remains pivotal. Whether you're enjoying the city's rich history or a stroll along the Bosphorus, it's essential to stay vigilant against UV damage. For more detailed insights into UV conditions throughout the year, visit Istanbul UV Index.
UV Risk Categories
As the summer fades into autumn, September in Istanbul still basks in a glorious 345 hours of sunshine, making it a perfect month for sun-seekers. This radiant month follows a peak summer bask with July leading the pack at 428 hours but gracefully transitions into the cozy warmth of early fall. Although the sunlight begins to dwindle, September still shines brighter than many winter months, significantly outpacing October's 305 hours and November's 247 hours. This trend illustrates Istanbul’s pleasant climate, inviting both tourists and locals to relish the lingering warmth before the cooler days ahead. The sunshine in September not only enhances the city's vibrant atmosphere but also creates a picturesque backdrop for exploring its rich history and culture.
In September, Istanbul experiences a delightful blend of summer's warmth and early autumn's charm, with a 58% chance of sunny weather. This marks a notable drop from the peak basking months of July and August, which boast a striking 79% and 82% chance of sunshine, respectively. As the city transitions into fall, the likelihood of sun remains markedly higher compared to the winter months, like January and December, where sunshine probability wanes to 27% and 33%. Thus, September offers a perfect opportunity to enjoy the last rays of summer before the cooler days set in, making it an ideal time for outdoor exploration in this vibrant city.
As summer gently wanes into autumn, September in Istanbul offers a comfortable 12 hours of daylight, marking a gradual decline from the sunlit heights of 15 hours in June. This month serves as a bridge between the vibrant warmth of late summer and the cooler days ahead, with daylight gradually decreasing from the summer peak. Though September bids farewell to the long, sun-drenched days of July and August, it still provides ample daylight to enjoy the city's rich history and stunning landscapes. As the year progresses toward October and its 11 hours of daylight, residents and visitors alike can savor the beauty of Istanbul's early fall, accentuated by shorter, pleasantly crisp days.
As September wraps Istanbul in its embrace, the city's winds begin to stir with a renewed energy, averaging 4.9 m/s (11 mph)—a tempo reminiscent of the lively summer months. This slight uptick in wind speed, compared to the more languid breezes of June and July, signals the transition towards autumn. The winds, while still gentle, herald a shift, capturing the vibrant essence of the city as it prepares for cooler days ahead. Notably, September's winds mirror the trend seen earlier in the year, where spring and summer echoes maintain a consistent rhythm before rising again in October. Such a dynamic contrast between the seasons adds to Istanbul's allure, inviting both locals and visitors to experience its rich tapestry of culture and history under a lively sky.
Weather in Istanbul varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Istanbul, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present stark contrasts in weather. In September, temperatures range from a mild 13°C (57°F) at night to a warm average of 22°C (72°F) and peak at 32°C (90°F) during the day, accompanied by relatively moderate humidity at 60% and only 36 mm (1.4 in) of precipitation over about six days. In contrast, January experiences much colder conditions, with temperatures falling as low as -3°C (27°F), averaging 7°C (45°F), and reaching a maximum of 16°C (62°F). The precipitation in January is significantly higher at 102 mm (4.0 in), spread over 13 days, and the humidity rises to 84%. For more detailed insights on January weather, you can visit Istanbul weather in January.
September and February showcase contrasting weather patterns. In September, temperatures range from a mild 13°C (57°F) to a warm 32°C (90°F), with an average of 22°C (72°F), while rainfall is relatively low at 36 mm (1.4 in) over about 6 days, accompanied by 60% humidity. Conversely, February brings much cooler temperatures, with lows dipping to -1°C (31°F) and highs peaking at 17°C (62°F), resulting in an average of 8°C (46°F). This month experiences higher precipitation at 66 mm (2.6 in) across 12 days, alongside increased humidity at 84%. For more detailed insights, you can check Istanbul weather in February.
September and March present contrasting weather conditions, showcasing the transition between summer and spring in Istanbul. In September, temperatures range from a minimum of 13°C (57°F) to a maximum of 32°C (90°F), with an average of 22°C (72°F) and relatively low precipitation of 36 mm (1.4 in) over about 6 days. The humidity is moderate at 60%, making for warm and pleasant days. In contrast, March experiences a significant drop in temperatures, with a minimum of -2°C (29°F) and a maximum of 18°C (65°F), averaging just 8°C (47°F). This month also sees higher precipitation levels at 82 mm (3.2 in) across roughly 12 days, coupled with increased humidity at 83%. For a more detailed look at the weather in March, you can visit Istanbul weather in March.
In comparing the weather between September and April, we find that September boasts a warmer climate, with average temperatures ranging from a minimum of 13°C (57°F) to a maximum of 32°C (90°F). In contrast, April experiences cooler temperatures, with averages from 4°C (40°F) to 23°C (73°F). Rainfall is also more prevalent in April, with 49 mm (1.9 in) of precipitation recorded over 8 days, compared to September's 36 mm (1.4 in) over just 6 days. Additionally, April has higher humidity levels at 76%, while September's humidity averages around 60%. For a more detailed look at April's weather, you can visit Istanbul weather in April.
In September, the weather warms up with temperatures ranging from a minimum of 13°C (57°F) to a maximum of 32°C (90°F), averaging around 22°C (72°F). This month receives less precipitation at 36 mm (1.4 in) over about 6 days and has a moderate humidity level of 60%. In contrast, May is cooler and wetter, with temperatures spanning from 8°C (46°F) to 27°C (82°F), averaging 17°C (63°F). It experiences higher rainfall, accumulating 50 mm (2.0 in) across 8 days, and a noticeably more humid atmosphere at 77%. For those looking for more details on May weather, you can explore Istanbul weather in May.
When comparing the weather in September to that in June, both months exhibit similar temperature ranges, with September experiencing a minimum of 13°C (57°F) and a maximum of 32°C (90°F), while June has a minimum of 13°C (56°F) and a maximum of 30°C (86°F). The average temperatures are virtually identical, sitting around 22°C (72°F). However, September tends to be slightly drier, with 36 mm (1.4 in) of precipitation over about 6 days, compared to June's 40 mm (1.6 in) spread over 7 days. Furthermore, June has a higher humidity level at 70%, compared to 60% in September. For more detailed information, you can check Istanbul weather in June.
In comparing the weather between July and September, one can see notable differences in temperature and precipitation patterns. July typically enjoys warmer conditions with an average temperature of 24°C (76°F) and a maximum of 33°C (92°F), while September features milder temperatures, with an average of 22°C (72°F) and a maximum of 32°C (90°F). In addition, July experiences slightly higher humidity at 63% compared to September's 60%. Precipitation is also more pronounced in July, with 53 mm (2.1 in) falling over 5 days, whereas September has 36 mm (1.4 in) over 6 days. For more details, you can check Istanbul weather in July.
In comparing the weather of September and August, September experiences a more moderate range of temperatures, with minimums around 13°C (57°F) and maximums reaching 32°C (90°F), averaging 22°C (72°F). In contrast, August tends to be warmer, with minimum temperatures of 19°C (66°F) and maximums climbing to 34°C (93°F), giving it an average of 25°C (77°F). Additionally, September sees slightly more precipitation, totaling 36 mm (1.4 in) over 6 days, whereas August receives only 18 mm (0.7 in) across 3 days, accompanied by lower humidity levels of 55% compared to 60% in September. For a detailed look at August weather, please visit Istanbul weather in August.
September typically offers warmer temperatures, with daily averages reaching up to 22°C (72°F) and maximums hitting 32°C (90°F). The month is characterized by relatively lower humidity at 60% and less frequent rain, averaging just 36 mm (1.4 in) over about 6 days. In contrast, October sees a noticeable drop in temperatures, with averages declining to 18°C (64°F) and maximums around 28°C (82°F). The humidity increases to 73%, and the precipitation rises to 56 mm (2.2 in) over 8 days. This shift marks a transition to cooler, wetter weather as fall progresses. For more detailed insights, check out Istanbul weather in October.
September typically features warmer weather with an average temperature of 22°C (72°F) and maximum highs reaching up to 32°C (90°F). In contrast, November ushers in cooler temperatures, with averages dropping to 14°C (57°F) and maximums peaking at 22°C (72°F). While September experiences relatively low precipitation of 36 mm (1.4 in) over 6 days, November sees an increase in rainfall to 63 mm (2.5 in) over 10 days, accompanied by higher humidity levels at 82%. For more detailed information, check out Istanbul weather in November.
September weather is characterized by warmer temperatures, with a minimum of 13°C (57°F) and an average high of 32°C (90°F). The month sees relatively low precipitation, totaling 36 mm (1.4 in) over about 6 days, and humidity levels are around 60%. In contrast, December brings a significant drop in temperature, with minimums reaching 1°C (34°F) and a much cooler average high of just 18°C (64°F). Precipitation is also higher in December, totaling 108 mm (4.2 in) over 15 days, accompanied by increased humidity at 85%. For more detailed information on December's weather, you can visit Istanbul weather in December.
As summer gently fades, September in Istanbul ushers in a delightful transition, offering a harmonious blend of warmth and crispness that sets it apart from the sweltering days of July and August. With average temperatures comfortably resting at 22°C (72°F) and fewer precipitation days, the city enjoys a pleasant ambiance, fostering perfect conditions for outdoor exploration. While humidity remains moderate, the occasional light rainfall adds a refreshing touch, making September an ideal time for visitors to experience Istanbul's rich culture and vibrant life. For those looking to understand Istanbul's diverse climate throughout the year, additional insights can be found at Istanbul Climate.