Last updated: August 21, 2025
September in Izu, Japan is characterized by a warm and humid climate, with temperatures peaking at a maximum of 33°C (91°F) and an average of 23°C (74°F), while dipping to a comfortable minimum of 15°C (60°F) during the cooler nights. Rainfall is significant this month, totaling 221 mm (8.7 in) over 20 days, contributing to the lush greenery that the region is known for. With humidity levels soaring at 86%, visitors can expect a tropical feel, making it a perfect time for those who enjoy warm weather and the refreshing ambiance created by the frequent showers.
In September, Izu, Japan, experiences a lovely transition into autumn, marked by mild temperatures that invite outdoor exploration. The month's average temperature settles around 23°C (74°F), with daytime highs reaching a warm 33°C (91°F), echoing the lingering warmth of summer. As the month progresses, the minimum temperature remains comfortable at about 15°C (60°F), setting a pleasant backdrop for evening strolls. This gradual shift from the sweltering heat of August, where temperatures peaked at 34°C (94°F), signifies a welcome change, allowing visitors and locals alike to enjoy the stunning natural landscapes without the oppressive heat. Overall, September in Izu embodies a perfect balance of warmth and comfort, making it an ideal time to visit.
In September, Izu, Japan, experiences a notable increase in precipitation, with 221 mm (8.7 in) of rainfall recorded over 20 days. This month marks a shift from the summer dryness of August, which received only 176 mm (6.9 in) across 17 days. The increase in both rain and rainy days is indicative of the transition into autumn, where atmospheric conditions begin to change, leading to more frequent showers. As the region prepares for the heavier rains of October, September serves as a pivotal month, balancing warm weather with the swelling of clouds, ultimately enriching the lush landscapes that Izu is famed for.
As September settles in Izu, Japan, the humidity remains notably high at 86%, continuing a trend seen throughout the summer months. After reaching a peak of 93% in July and a close 90% in August, humidity levels begin to taper off, yet they are still significantly elevated compared to the earlier months of the year. Notably, this month marks a slight decrease from August, suggesting a subtle transition toward the drier autumn months ahead. While January's 76% sets a baseline, the humidity rises dramatically from spring into summer, peaking mid-year before gradually trending downwards. This seasonal pattern underscores Izu's humid subtropical climate, where the warm, wet summer months give way to a gentler autumn, while still keeping a grip on that characteristic moisture.
In September, Izu, Japan, experiences a UV Index of 10, marking a shift from the extreme levels seen during the summer months. This very high exposure category indicates that individuals should be cautious, with a burn time of just 15 minutes. As autumn approaches, the UV levels begin to decline from the summer peaks, yet it remains essential to protect your skin during these final days of warmth. The trend shows that while September still has significant sun intensity, vigilance is paramount to avoid sunburn. For further details on UV levels and safety measures, visit Izu UV Index.
UV Risk Categories
As summer fades into autumn, September in Izu, Japan, offers a delightful transition with 236 hours of sunshine. This month balances the energetic warmth of August, which boasts an impressive 285 hours, while stepping back from the peak of summer. Interestingly, the trend shows a gradual increase in daylight from the beginning of the year, peaking in late spring with 282 hours in May and then fluctuating throughout the summer. September's sunshine hours reflect a comforting consistency, providing a perfect backdrop for exploring the area's stunning landscapes as nature begins to don its fall colors. It’s a month where the lingering warmth invites both locals and visitors to bask in the sun before the cooler days of autumn set in.
In September, the likelihood of sunny weather in Izu, Japan, is 31%, a modest uptick from the summer months that experienced lower sunshine rates. This period marks a transitional phase as it bridges the end of the sweltering summer and the onset of the milder fall season. While September doesn’t quite compete with the sunnier months of January (59%) and November (62%), it offers more reliable sunshine than the peak of the rainy season in June (22%) and July (30%). As the days gradually shorten, visitors can still enjoy a good balance of sunshine and warmth before the cooler October arrives, which has a 44% chance of clear skies. Embracing September's unique charm, travelers can relish the gentle shifts in weather while exploring the stunning landscapes that Izu has to offer.
In September, Izu, Japan, experiences a gentle transition in daylight duration, basking in 12 hours of sunlight. Following the long summer days, which peaked at 14 hours in June and July, the daylight begins to wane as autumn approaches. This gradual decrease continues into October, where the sun shines for 11 hours. The month of September strikes a harmonious balance, offering slightly less daylight than August's 13 hours, yet more than the months that follow. This trend reflects Izu's beautiful seasonal shifts, where the warmth of summer gradually gives way to the cooler, crisp days of fall, inviting residents and visitors alike to savor the changing scenery and vibrant landscapes of this coastal gem.
As September arrives in Izu, Japan, the gentle breezes begin to weave through the coastal landscape, with an average wind speed of 2.9 m/s (7 mph)—a figure that echoes the mild winds of August. Throughout the year, Izu experiences a noticeable decline in wind speed during the warmer months, hitting a low of 2.0 m/s (4-5 mph) in June and July. However, as autumn approaches, the winds gradually pick up again. With the average speed climbing slightly in September, it sets the stage for a refreshing transition into the cooler months, where gusts of 3.1 m/s (7 mph) in November and returning to 3.3 m/s (7 mph) by December remind residents and visitors alike of nature's rhythms. This seasonal dance of breezes not only enhances the breathtaking scenery, but also infuses the region with an invigorating energy, inviting exploration and reflection in the heart of Japan.
Weather in Izu varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Izu, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present stark contrasts in weather. In September, temperatures can reach a high of 33°C (91°F), with an average of 23°C (74°F) and a relatively high humidity of 86%. This month is characterized by frequent rain, with about 221 mm (8.7 inches) of precipitation over 20 days. In contrast, January experiences cooler temperatures, ranging from a minimum of -2°C (29°F) to a pleasant maximum of 18°C (64°F), with an average of 7°C (44°F). Rainfall is significantly less in January, totaling only 68 mm (2.7 inches) over just 5 days, and humidity drops to 76%. For more detailed insights, you can check Izu weather in January.
In September, the weather is significantly warmer with temperatures ranging from a minimum of 15°C (60°F) to a maximum of 33°C (91°F), creating an average of 23°C (74°F). This month also sees frequent rainfall, with 221 mm (8.7 in) of precipitation over 20 days and a high humidity level of 86%. In contrast, February experiences much cooler conditions with a minimum temperature of -1°C (30°F) and a maximum of 19°C (67°F), averaging around 7°C (45°F). Precipitation is also lower in February at 83 mm (3.2 in) over 8 days, accompanied by a humidity level of 74%. For more detailed weather predictions, check Izu weather in February.
The comparison between September and March reveals a distinct contrast in weather patterns. In September, temperatures range from a minimum of 15°C (60°F) to a scorching maximum of 33°C (91°F), with an average of 23°C (74°F). This month is characterized by high humidity at 86% and significant rainfall, totaling 221 mm (8.7 in) over approximately 20 days. In contrast, March presents a much cooler climate, with temperatures dipping to a minimum of 1°C (34°F) and reaching a maximum of 22°C (72°F), averaging just 11°C (51°F). While March sees less precipitation at 196 mm (7.7 in) over 13 days, it also features lower humidity at 70%. For more details, you can check Izu weather in March.
When comparing the weather in September and April, there is a notable difference in temperature and humidity levels. September features a much warmer climate, with temperatures ranging from a minimum of 15°C (60°F) to a maximum of 33°C (91°F), accompanied by high humidity at 86%. In contrast, April experiences cooler temperatures, with a minimum of 3°C (38°F) and a maximum of 24°C (76°F), and lower humidity at 74%. Additionally, September sees higher precipitation, with 221 mm (8.7 in) over 20 days, compared to April’s 168 mm (6.6 in) across just 11 days. For more specific weather details in Izu during April, check out this link: Izu weather in April.
September and May present quite different weather experiences. In September, temperatures range from a mild 15°C (60°F) at night to a warm 33°C (91°F) during the day, while May offers cooler temperatures, starting at 9°C (48°F) and peaking at 28°C (82°F). September is also marked by higher humidity at 86%, compared to May's 81%, and experiences more precipitation, totaling 221 mm (8.7 in) over 20 days, while May sees 194 mm (7.6 in) over just 12 days. For those interested in specific weather conditions during this month, check out Izu weather in May.
In comparing the weather of September and June, we see some notable differences. September typically experiences slightly warmer temperatures, with an average of 23°C (74°F) and a maximum of 33°C (91°F), whereas June's average hovers around 21°C (71°F) with a peak of 29°C (85°F). However, June has a higher level of precipitation, totaling 263 mm (10.3 in) over about 17 days, compared to September's 221 mm (8.7 in) over 20 days. Humidity levels are similar, with September averaging 86% and June at 88%. For a more detailed perspective on June weather, you can check out Izu weather in June.
Comparing the weather in September and July reveals some interesting trends. July tends to be slightly warmer, with average temperatures reaching 25°C (77°F) and a minimum of 18°C (65°F), while September has a lower average of 23°C (74°F) and a minimum of 15°C (60°F). Both months experience high maximum temperatures, peaking at 33°C (91°F) in September and 33°C (92°F) in July. However, July has significantly higher precipitation, totaling 326 mm (12.8 in) over 19 rainy days, compared to September's 221 mm (8.7 in) across 20 days. The humidity is also higher in July at 93%, while September sits at 86%, making it feel a bit more comfortable. For more insights, you can check Izu weather in July.
In comparing the weather conditions between September and August, September tends to be slightly cooler, with temperatures ranging from a minimum of 15°C (60°F) to a maximum of 33°C (91°F) and an average of 23°C (74°F). In contrast, August experiences warmer temperatures, with a minimum of 20°C (68°F), an average of 27°C (81°F), and a peak of 34°C (94°F). Despite September having a higher total precipitation of 221 mm (8.7 in) over 20 days compared to August's 176 mm (6.9 in) over 17 days, the humidity levels are quite similar, with September at 86% and August at 90%. For more specific insights, you can check out the detailed weather information Izu weather in August.
In comparing the weather between September and October, we see a noticeable shift in both temperature and precipitation patterns. September boasts warmer temperatures, with a minimum of 15°C (60°F) and an average of 23°C (74°F), while October's temperatures decrease, featuring a minimum of 11°C (52°F) and an average of 19°C (66°F). Additionally, October experiences higher precipitation levels, totaling 305 mm (12.0 in) over 16 days, compared to September’s 221 mm (8.7 in) over 20 days. Humidity remains relatively high in both months, with September at 86% and October slightly lower at 83%. For more detailed information about the weather conditions during this time, you can explore Izu weather in October.
September and November present contrasting weather characteristics. In September, temperatures are considerably warmer, with average highs reaching up to 33°C (91°F) and an average of 23°C (74°F). However, it also sees high humidity levels at 86% and significant rainfall, accumulating 221 mm (8.7 in) over 20 days. In contrast, November experiences much cooler temperatures, with a maximum of 22°C (72°F) and an average of just 14°C (58°F). Precipitation is lower in November, totaling 94 mm (3.7 in) across 10 days, and humidity drops slightly to 80%. These changes from September to November highlight a transition from a humid, warm late summer climate to the chillier, drier atmosphere of late autumn. For more specifics on November weather, check out Izu weather in November.
September weather is characterized by warmer temperatures, with a minimum of 15°C (60°F) and an average of 23°C (74°F), reaching up to a maximum of 33°C (91°F). The month also sees considerable rainfall, with 221 mm (8.7 in) of precipitation spread over about 20 days, coupled with high humidity at 86%. In contrast, December experiences much cooler temperatures, with a minimum of 0°C (32°F) and an average of 9°C (49°F), peaking at 21°C (69°F). The precipitation drops significantly to 74 mm (2.9 in) over just 8 days, and the humidity falls to 78%. For those interested in more details about December weather, you can visit Izu weather in December.
As summer transitions to autumn in Izu, September brings a unique blend of warmth and moisture, standing out from the milder, drier months that bookend it. With average temperatures reaching a comfortable 23°C (74°F) while peaking at highs of 33°C (91°F), you can enjoy the lingering summer vibes. However, this month is also marked by significant precipitation, with rain gracing the area on about 20 days, creating a notably humid atmosphere at 86%. This weather pattern not only sets September apart from the drier late summer days but also enhances the lush landscapes Izu is renowned for. To learn more about what to expect throughout the year, check out the full details on the Izu Climate.