Japan Central Alps · October 2026
October in Tōhoku is the good half of autumn — dry-ish, clear, the colour coming down the mountains to meet you. The catch is that every forecast number you will read is measured in a valley, and you will not be riding in the valley.
The one rule
Subtract 6 °C (11 °F) for every 1,000 m (3,300 ft) you climb — then another 4 °C (7 °F) for the wind.
Weather stations sit in towns, near the valley floor. Air cools about 6.5 °C (12 °F) for every 1,000 m (3,300 ft) of altitude, and riding at 80 km/h (50 mph) strips off roughly another 4–5 °C (7–9 °F) of apparent warmth. A forecast of 16 °C (61 °F) in Morioka is about 6 °C (43 °F) at the top of a 1,500 m (4,900 ft) pass, and feels like 1 °C (34 °F) through the vents. This is the gap that catches people out: they read the number, pack for the number, and freeze at the summit.
The cold, day by day
These are the regional October normals, adjusted where the night's lodging itself sits high. The right-hand column is the number that matters: what the exposed part of the day actually feels like.
| Date | Leg | Destination high / low | High ground | Coldest it will feel |
|---|---|---|---|---|
| Mon 10/5 | Tokyo → Shima Onsen179 km (111 mi) | 21/14 → 16/9 °C70/57 → 61/48 °F | 1,084 m Lake Haruna, Route 283,556 ft | 9 °C (48 °F) arriving late |
| Tue 10/6 | Shima Onsen → Sanjo242 km (150 mi) | 16/9 → 20/12 °C61/48 → 68/54 °F | 2,172 m Shibu Pass, R2927,126 ft | 0–5 °C (32–41 °F) at the top |
| Wed 10/7 | Sanjo → Zaō (Kaminoyama)181 km (113 mi) | 20/12 → 19/10 °C68/54 → 66/50 °F | Sea level to basin; Zaō towers above | 10 °C (50 °F) at dawn |
| Thu 10/8 | Zaō → Nikaho Onsen206 km (128 mi) | 19/10 → 19/11 °C66/50 → 66/52 °F | Basin to Sea of Japan coast | 10 °C (50 °F) at dawn |
| Fri 10/9 | Nikaho → Iwate (Shizukuishi)156 km (97 mi) | 19/11 → 16/8 °C66/52 → 61/46 °F | Over the Ōu range, 600–800 m2,000–2,600 ft | 5 °C (41 °F) on the tops |
| Sat 10/10 | Golf — Hachimantai CCno riding | 16/8 °C61/46 °F | Foothills, 8:59 tee | 8 °C (46 °F) on the first tee |
| Sun 10/11 | Shizukuishi → Naruko Onsen175 km (108 mi) | 16/8 → 18/9 °C61/46 → 64/48 °F | Naruko Gorge, 300 m1,000 ft | 8 °C (46 °F) at dawn |
| Mon 10/12 | Naruko → Kaminoyama Onsen196 km (122 mi) | 18/9 → 19/10 °C64/48 → 66/50 °F | Shortest day, back roads | 9 °C (48 °F) at dawn |
| Tue 10/13 | Kaminoyama → Aizu158 km (98 mi) | 19/10 → 19/9 °C66/50 → 66/48 °F | Rolling, some 600 m ground2,000 ft | 6 °C (43 °F) on the tops |
| Wed 10/14 | Aizu → Yunishigawa Onsen188 km (117 mi) | 19/9 → 15/7 °C66/48 → 59/45 °F | Ōuchi-juku 650 m, inn at 700 m2,100 ft / 2,300 ft | 7 °C (45 °F) arriving |
| Thu 10/15 | Yunishigawa → Tokyo237 km (147 mi) | 15/7 → 21/14 °C59/45 → 70/57 °F | 700 m down to sea level2,300 ft | 7 °C (45 °F) start, 21 °C (70 °F) finish |
Temperatures and elevations in the table are approximate. Three days do the work: 10/6 crosses Shibu Pass at 2,172 m (7,126 ft), the highest point on any national road in Japan and by a wide margin the coldest riding of the trip, 10/10 is the coldest standing still, and 10/15 swings 14 °C (25 °F) from first gear to the hotel. Everything else is a jacket-liner decision, not a problem.
When to check, and where
What to pack
One trip spans 21 °C (70 °F) Tokyo afternoons and near-freezing dawns at 1,100 m (3,600 ft). Layers solve that; a single warm jacket does not.
On the bike
Off the bike