Shimo-suwa Temperature by Month

Shimo-suwa in Nagano Prefecture, Japan sees significant seasonal temperature differences, with daytime highs between 3°C (37°F) in January and 28°C (82°F) in August, averaging 16°C (61°F) annually. Explore the full monthly breakdown below.

In Shimo-suwa, temperatures differ significantly between summer and winter months. Nighttime lows reflect this range, dropping from 18°C (64°F) in August to -7°C (19°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Shimo-suwa by month:

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. August, the warmest month, sees 197 hours of sunshine.

The chart below shows the average temperature throughout the year:

Shimo-suwa's average annual maximum temperature is 16°C (61°F). To put that in context, here's how it compares to a few well-known destinations:

Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.

On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.

Seoul, South Korea averages 18°C (64°F) a year, with four clear seasons, cold winters, and hot humid summers.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Shimo-suwa, January is the coolest month, with average highs of 3°C (37°F) and humidity around 57%, considered moderate. In August, the warmest month, temperatures average 28°C (82°F) with 71% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round, large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.

For more on Shimo-suwa's weather, including monthly rainfall, sunshine hours, and humidity, visit our Shimo-suwa climate page.