Kusatsu Onsen in December: weather, what to wear and what's on

Averages for 1991–2020 at the JMA's Kusatsu station (1,223 m above sea level).

High

2.9°C (37°F)

Low

−4.8°C (23°F)

Precipitation

60.4 mm

Wet days

10.9 days

Sunshine

162 hours

• Highs fall 6.2°C from November and drop another 3.3°C into January.
• That is 9.4°C below Kusatsu Onsen's yearly average high of 12.3°C.
• Of our 34 places with temperature records, Kusatsu Onsen is the 2nd coldest in December: 0.3°C cooler than Hakodate and 0.9°C warmer than Sapporo.
• Of our 35 places, Kusatsu Onsen has the 16th lowest precipitation in December: 0.8 mm less than Kumamoto and 0.3 mm more than Nasu.
• Rain or snow of 1 mm or more falls on 10.9 days, and 10 mm or more on 1.6 days.
• The temperature drops below 0°C on 29.2 nights.
• On 7.4 days it stays below 0°C all day.
• 112 cm of snow falls in an average December; snow 5 cm or deeper lies on the ground on 15.0 days.
• The sun is out for 40% or more of the possible hours on 21.3 days, and 0.4 days have under 0.1 hours of sunshine.

Average temperature

−1.2°C (30°F)

Deepest snow (average of each year's deepest)

37 cm

Early, mid and late December

By the last ten days of December the average high in Kusatsu Onsen is 3.5°C lower than in the first ten.

By ten-day totals, 21–31 December is the wettest (27.1 mm) and 1–10 December the driest (15.3 mm).

Is Kusatsu Onsen cold in December?

Yes, it is very cold. Kusatsu Onsen averages 2.9°C (37°F) by day and −4.8°C (23°F) at night in December. It gets colder still: 21–31 January has highs of −0.8°C.

Freezing: highs around 2.9°C

• A heavy winter coat (down or similar), thermal underwear, a hat, gloves and a scarf.
• Gloves and a hat for mornings and nights: the temperature drops below 0°C on 29.2 nights.
• A waterproof jacket with a hood: rain or snow falls on 10.9 days.

Shoes

• Waterproof boots with good grip: snow 5 cm or deeper lies on the ground on 15.0 days (deepest 37 cm on average).

Pack

• Waterproof jacket with a hood
• Gloves and a warm hat
• Thermal underwear
• Scarf
• Waterproof boots with grip

• Our clothing rules

There are no national holidays in December 2026.

In December 2025, hotels and inns across Gunma Prefecture were 43.4% full on average (11th busiest of 12 months). Foreign guests spent 39,100 nights there that month (Japan Tourism Agency). That compares with 48.0% in November and 41.2% in January.

• Japan in December: visitor numbers and busy travel days
• Holidays in December
• Year-end and New Year holidays