Tosu

Find out what weather to expect in Tosu. Below are the latest weather reports, detailed forecasts, and visual weather charts to help you plan your day.

The city of Tosu in Japan is characterized by a humid subtropical climate, which means it has four distinct seasons. Winters here are quite mild and relatively dry, with average temperatures in January and December around 5.8°C - 7.1°C. Spring brings a gradual and pleasant warming along with an increase in precipitation, preparing the transition to a warmer and more humid period.

Summer in Tosu is the warmest and wettest season. Average temperatures in July and August hold steady in the 26-28°C range, and maximum values often exceed 30°C. The peak of precipitation occurs during the summer months, especially June and July. For example, in July, the number of rainy days can reach 21, indicating a pronounced summer rainy season. Autumn brings a gradual decrease in temperature and humidity, creating comfortable and often sunny conditions for visiting the city.

The city of Tosu exhibits a pronounced seasonality in its temperatures. Annual temperature trends show that January is the coldest month, with an average temperature of 5.8°C, nightly lows around 2.6°C, and daily highs reaching 9.1°C. December and February are only slightly warmer. The hottest month is August, when the average temperature rises to 27.9°C, and daytime peaks can reach 31.2°C. July also features high temperatures, with an average of 26.7°C.

The summer period in Tosu, spanning June, July, and August, is characterized as hot and humid. In June, the average temperature is a comfortable 22.8°C, but by July and August, the mercury regularly crosses the 29–31°C mark during the day, while nights remain very warm, with temperatures around 24–25°C. Since July has the highest number of rainy days (21), and June and August also have many (15–16 days), the summer heat is often accompanied by high humidity, making it feel more intense.

Winter in Tosu is generally cool but mild. In December, January, and February, average daytime temperatures range from 9°C to 10.5°C, while nightly lows drop to 2.6–3.9°C. Although light frosts are possible, severe and prolonged freezing temperatures are not typical for this region. Temperature fluctuations between daily highs and nightly lows are most pronounced during the transitional seasons—spring (March, April) and autumn (October, November)—when the difference can be around 8°C. In summer, the diurnal temperature range is smaller, indicating consistently warm weather both day and night.

The city of Tosu experiences pronounced seasonality in the distribution of precipitation throughout the year. The climate is characterized by a humid summer period and a drier winter. Given the average monthly temperatures, precipitation here falls primarily as rain; significant or regular snowfall is unlikely based on the provided temperature data.

The highest amount of precipitation occurs during the summer months, forming a distinct rainy season. July is the wettest month, with an average of about 11 mm of precipitation and up to 21 rainy days. June is also rainy, with 9 mm of precipitation and approximately 15 rainy days. August and September continue this trend with 8 mm and 6 mm of precipitation respectively, also seeing a significant number of days with precipitation (16 and 15 days). May also belongs to the wetter period with 5 mm of rainfall and 13 rainy days.

In contrast, the winter months are the driest. November, December, and January stand out with minimal precipitation—only about 2 mm each. The number of rainy days during this period is also the lowest, ranging from 8 to 10 days. Spring months such as March (4 mm, 11 days) and April (4 mm, 10 days), as well as mid-autumn in October (3 mm, 9 days), are transitional periods with moderate precipitation.

When planning a trip to Tosu, it is important to consider the weather variability throughout the year to ensure your stay is as comfortable as possible. Comfortable walking shoes are a must in any season, as the city is perfect for exploring on foot. In winter (December–February), average temperatures hover around 5–7°C, so be sure to pack warm clothing: sweaters, a fleece, a warm jacket (preferably windproof), a hat, gloves, and a scarf. Although the total rainfall in millimeters is low, there are many rainy days (8–10 per month), so a lightweight folding umbrella or a waterproof jacket will be very useful. In spring (March–May), the weather gradually warms up, averaging between 10°C and 19°C, but the principle of layering remains relevant: t-shirts, light sweaters, and a mid-weight jacket will help you adapt to temperature changes throughout the day. In May, the number of rainy days increases to 13, so an umbrella is still necessary.

Summer in Tosu (June–August) is the warmest and most humid time of year. Average temperatures rise to 23–28°C, and maximums can exceed 30°C. This period sees the highest amount of precipitation, and the number of rainy days can reach 15–21 per month, especially in July. We recommend bringing light, breathable clothing made from natural fabrics (cotton, linen). A reliable umbrella or a high-quality lightweight raincoat will be your indispensable companions. Don't forget sunscreen with a high SPF, a hat or cap, and sunglasses. In autumn (September–November), the temperature gradually drops from a warm 24°C in September to a cooler 13°C in November. Layering will come in handy again: light jackets and sweaters are recommended. While there is less precipitation in autumn, especially in October and November (8–9 rainy days), it is still worth having a compact umbrella with you, especially in early autumn when September can still see up to 15 rainy days.