Overnight temperatures in Tokyo rarely fall below 0 degrees Celsius, and daytime temperatures usually manage to creep up to at least 6 or 7 degrees. In an average winter Tokyo gets no more than a mere two or three snowfalls which means there is little excuse not to ride to work. In comparison with the recent Polar Vortex which has frozen large parts of the United States its practical tropical in Tokyo during the winter.
I commute daily in my work clothes and have cycled past winters in the following kit:
Natural layer of body fat
Woolen Turtle Neck Sweater
Whatever socks don't have holes in them
Dr. Martens Boots
That's it, essentially its just what happens to be in my wardrobe at the time. In fact I'd have dress warmer to survive a walk to the train station, by switching the helmet for a wool hat and replacing the windstopper jacket with a down jacket, as my body could not generate enough heat to keep warm just by walking.
I'm rather flexible when it comes to riding in the rain, but I avoid cycling to work when there is snow and ice on the ground. Sure people cycle in the snow for months on end in colder parts of the world, but I grew up in Australia where it never snows and as such I have little experience cycling on icy roads. Given the infrequency of snowfalls in Tokyo I've little opportunity to learn to ride on snow. So on those rare snowy I actually prefer walking to the station, because to anyone who grew up in Australia snow fascinating.
Fair weather riders like me aside, intrepid Tokyo cyclists will kit up and cycle icy and snow covered roads and sidewalks the few times a year it does actually snow in Tokyo because they know the convenience of the bicycle can't be outweighed by the inconvenience of a little snow on the ground.
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