Read the wind and the rain before you pick your month.

station

JMA's Ajiro station (block 47668) stands at 66.9 m above Ajiro in Atami city, on the east coast of the Izu peninsula. Shuzenji has no JMA station, and the one at Yugashima (block 0453) south of it records precipitation only. Ajiro stands in for the peninsula here, and Mishima's observatory (block 47657) north of Shuzenji is the other option. Every value is JMA's 1991–2020 normal.

snow

JMA's snow normals at Ajiro cover only 1991–2003, so this file leaves snow out.

winter

January highs average 10.7 °C and lows 3.9 °C. Rain of 1 mm or more falls on 6.1 days in January, and the month gets 147.4 hours of sunshine. The west-south-west wind averages 3.4 m/s.

spring

March rain jumps to 158.0 mm from 82.0 mm in February, and highs reach 18.8 °C in April. September is the wettest month of the year at 263.9 mm.

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Aso-Otohime AMeDAS station (block 1240) stands at 487 m inside the Aso caldera in Kumamoto. JMA's summit station at Asosan (block 47821) stopped observing on 11 December 2017, and JMA keeps no snow normals at Aso-Otohime. Every value is JMA's 1991–2020 normal.

winter

January lows average −2.7 °C and highs 7.1 °C. The month gets 106.6 hours of sunshine.

spring

Highs run from 12.7 °C in March to 22.5 °C in May. June averages 667.9 mm of rain and July 582.6 mm, so plan Aso riding for spring or autumn.

volcano

Aso is an active volcano that JMA monitors. Check the current alert level on JMA's Asosan page before riding up to the crater: https://www.data.jma.go.jp/vois/data/fukuoka/503_Asosan/503_index.html

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Hakuba AMeDAS station (block 0396) stands at 703 m on the floor of the Hakuba valley in Nagano. The lifts of every Hakuba resort climb well above it, so expect colder air on the upper slopes than these figures show. Every value is JMA's 1991–2020 normal.

winter

January is the coldest month, with a mean daily low of −7.2 °C and a high of 1.4 °C. New snow totals 216 cm in January and 174 cm in February. On the valley floor the normal deepest snow peaks at 97 cm in February.

spring

By April the normal deepest snow in the valley is down to 7 cm and daily highs reach 14.6 °C. May is the sunniest month at 193.8 hours. Rain peaks in July at 280.8 mm.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Hikone station (block 47761) stands at 87.3 m on the east shore of Lake Biwa in Shiga. It is the nearest full JMA station to the Biwaichi loop. Nagahama to the north has an AMeDAS station (block 0976), though JMA keeps no snow normals there. Every value is JMA's 1991–2020 normal.

winter

A steady north-west wind blows through winter, averaging 3.7 m/s in January and 4.0 m/s in February. Highs in January average 7.1 °C. January's normal deepest snow on the ground is 19 cm.

spring

Highs reach 17.4 °C in April and 22.6 °C in May, and May gets 197.3 hours of sunshine. The rainy season pushes June to 175.6 mm and July to 219.0 mm.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Ikuchijima AMeDAS station (block 0687) stands 3 m above sea level on Ikuchijima in Hiroshima prefecture. The Shimanami Kaido crosses the island on its way from Onomichi to Imabari. JMA called it Innoshima until 26 February 2009. Onomichi has no JMA station of its own, and the nearest observatory with humidity records is Fukuyama (block 47767). JMA keeps no snow normals at Ikuchijima. Every value is JMA's 1991–2020 normal.

winter

January is the driest month at 39.5 mm, with 1 mm or more of rain on 5.3 days and 141.9 hours of sunshine. Highs average 9.5 °C and lows 1.6 °C, so calm clear days make for good winter riding on the islands.

spring

Highs climb from 13.0 °C in March to 22.9 °C in May, and May gets 206.5 hours of sunshine. June and July are the wettest months at 172.3 mm and 177.6 mm.

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Imabari AMeDAS station (block 1077) stands at 27 m in Imabari city, Ehime, at the Shikoku end of the Shimanami Kaido. JMA keeps no snow normals for it. Every value is JMA's 1991–2020 normal.

winter

January highs average 9.8 °C and lows 1.8 °C. Precipitation of 1 mm or more falls on 6.7 days that month, and the sun shines for 139.6 hours.

spring

May gets 215.0 hours of sunshine and highs of 23.6 °C. June brings the most rain at 196.2 mm, and August tops the year for sunshine at 229.7 hours.

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Iwate-Matsuo AMeDAS station (block 0214) stands at 275 m in Hachimantai city, Iwate. APPI and the Hachimantai ski areas sit higher in the mountains, so their slopes run colder than these figures. Every value is JMA's 1991–2020 normal.

winter

January lows average −7.9 °C and highs 0.8 °C. New snow totals 122 cm in January, and the normal deepest snow peaks at 39 cm in February. Precipitation stays light in the valley, at 42.5 mm in January.

spring

Highs reach 13.5 °C in April and 19.8 °C in May. May is the sunniest month at 187.9 hours.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Kusatsu AMeDAS station (block 0343) stands at 1,223 m in Kusatsu town, Gunma. The ski area's lifts climb above it. Every value is JMA's 1991–2020 normal.

winter

January is the coldest month, with a mean of −4.1 °C and lows of −7.8 °C. It also gets 153.0 hours of sunshine. The normal deepest snow peaks at 94 cm in February.

spring

Highs reach 11.5 °C in April and 17.0 °C in May. The rain comes later in the year, and July is the wettest month at 263.5 mm.

volcano

Kusatsu-Shirane is an active volcano that JMA monitors. Check the current alert level on JMA's Kusatsu-Shirane page before heading up: https://www.data.jma.go.jp/vois/data/tokyo/305_Kusatsu-Shiranesan/305_index.html

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Minakami AMeDAS station (block 1019) stands at 524 m in Minakami town, Gunma, in the Tone valley below the town's ski areas. JMA wrote its name as 水上 until 28 February 2006. Every value is JMA's 1991–2020 normal.

winter

January brings 296 cm of new snow, and February holds the deepest normal snowpack at 149 cm. Daily lows average −4.4 °C in January and −4.3 °C in February. The wind blows most often from the east-north-east in every month of the year.

spring

The normal deepest snow falls to 34 cm in April as highs reach 14.4 °C. May is the sunniest month at 192.1 hours.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Nozawa Onsen AMeDAS station (block 0393) stands at 576 m beside Nozawa Onsen village in Nagano. The ski area's lifts rise above it, so the upper slopes run colder than these figures. Nozawa has its own normals, so this file uses them in place of Iiyama's. Every value is JMA's 1991–2020 normal.

winter

January averages 366 cm of new snow and 253.5 mm of precipitation, with 1 mm or more falling on 22.1 days. The normal deepest snow reaches 199 cm in February. Daily highs in the village average 1.7 °C in January and 2.6 °C in February.

spring

April's normal deepest snow drops to 77 cm, and the valley is clear of snow by May. May is the sunniest month at 205.8 hours, with highs of 20.8 °C.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Sekiyama AMeDAS station (block 0998) stands at 350 m in Myoko city, Niigata. It sits in the valley below Myoko Kogen, where the ski areas start higher up the mountain, so the resorts run colder than these figures. Every value is JMA's 1991–2020 normal.

winter

January averages 385 cm of new snow, and precipitation of 1 mm or more falls on 22.4 days that month. February holds the deepest normal snowpack at 192 cm. The valley air stays mild for that much snow, with January highs of 3.3 °C and lows of −2.7 °C.

spring

April's normal deepest snow falls to 43 cm as daily highs reach 15.0 °C. May is the sunniest month at 192.3 hours.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Sukayu AMeDAS station (block 1079) stands at 890 m at Sukayu Onsen in the Hakkoda mountains of Aomori. The Hakkoda Ropeway climbs above it, and the upper slopes run colder still. Every value is JMA's 1991–2020 normal.

snow

Sukayu's normal deepest snow reaches 373 cm in February and 372 cm in March, and January averages 454 cm of new snow. JMA's record snow depth at Sukayu is 566 cm, set on 26 February 2013.

winter

January is cold and dark, with a mean of −7.5 °C and 11.8 hours of sunshine for the whole month. The wind blows most often from the west-north-west at 3.2–3.4 m/s from December to March.

spring

April's normal deepest snow is still 325 cm and May's is 187 cm. May is the sunniest month at 176.4 hours.

volcano

Hakkoda is an active volcano that JMA monitors. Check the current alert level on JMA's Hakkoda page before touring: https://www.data.jma.go.jp/vois/data/sendai/203_Hakkodasan/203_index.html

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Takayama station (block 47617) stands at 560 m in Takayama city, Gifu, on the floor of the Hida basin. The ski areas of Okuhida and the road up Norikura sit far higher, so expect colder air there. Every value is JMA's 1991–2020 normal.

winter

January and February lows average −4.8 °C and −4.9 °C. New snow totals 117 cm in January, and the normal deepest snow reaches 45 cm in February. Humidity peaks at 84% in December.

spring

Highs climb from 9.8 °C in March to 22.9 °C in May. May is the sunniest month at 189.2 hours, and July is the wettest at 260.9 mm.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Yamagata station (block 47588) stands at 152.5 m in Yamagata city, on the basin floor below Mt. Zao. Zao Onsen and its ropeways sit much higher up the mountain, so expect colder air there than these figures show. JMA's Zaosan station stopped observing in 2009, which leaves Yamagata as the nearest station with full normals. Every value is JMA's 1991–2020 normal.

winter

January and February share the coldest lows at −3.1 °C, with highs of 3.3 °C and 4.4 °C. The city gets 103 cm of new snow in January. Its normal deepest snow peaks at 47 cm in February.

spring

Highs climb from 9.1 °C in March to 22.6 °C in May, and May is the sunniest month at 196.5 hours. Humidity drops to its yearly low of 62% in April.

volcano

Mt. Zao is an active volcano that JMA monitors. Check the current alert level on JMA's Zao page before heading up: https://www.data.jma.go.jp/vois/data/sendai/212_Zaozan/212_index.html

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.

station

JMA's Yuzawa AMeDAS station (block 0544) stands at 340 m on the valley floor in Yuzawa town, Niigata. The lifts at Kagura and Naeba climb far above it, so expect colder air on their slopes. Every value is JMA's 1991–2020 normal.

winter

January is the wettest month of the year at 314.9 mm and brings 377 cm of new snow on average. The normal deepest snow peaks at 202 cm in February. Sunshine is scarce in midwinter, at 45.8 hours for January.

spring

By April the normal deepest snow has fallen to 52 cm and daily highs reach 15.3 °C. May is the sunniest month at 189.4 hours.

snowSeries

Two snow series come from JMA's normals. snowDepthMax is the month's deepest snow on the ground in centimetres (最深積雪), and freshSnow is the month's total new snowfall in centimetres (降雪の深さ合計).

rain

Rain days count the days with 1 mm or more of precipitation.

wind

The windDir field holds JMA's most frequent wind direction (最多風向) for each month as the compass point the wind blows from.