How to dress in Asahikawa at different times of year
To put it simply, Asahikawa is really cold in winter and can be hot (sometimes humid) in summer. As well as that, day and night-time temperature differentials require you to adjust your clothes to suit. Knowing what to pack and wear at different times of year in Asahikawa can save you a lot of discomfort.
Winter
Winter (December, January, February)
Dress as warm as you can possibly imagine during these months, both day and night. Note that although outside is cold, buildings and public transport are often very warm so it helps to wear layers that are easily removed. Be weary of sunny mornings, this often means less cloud hence less insulation, and so super-cold temperatures. As far as shoes go, make sure that you bring shoes that have at least some tread on the bottom. The major streets in the city have warmed pavements, but chances are that you'll still be walking on ice half of the time. Negotiating the ice with perfectly smooth soles is a distinctly unpleasant experience. Please also be aware that buying shoes once you arrive may not be an ideal option if your shoe size is larger than 27cm. Such sizes are large by local standards and can be difficult (though not impossible) to find.
Spring
The cold eases somewhat and temperatures start to climb. You will still need to dress warm in March, while from April, you'll be able to get by with a spring coat or heavy sweater. The temperature tends to jump up and down sharply during spring so its generally advisable to take a spare layer with you.
Summer
The hottest temperatures in Asahikawa generally occur around Obon (the second week of August.) June can have its moments of cold weather and rain, but a single layer will usually be enough. All of July is likely to be comfortable warm, allowing for very light clothes day or night. The first 2/3 of August are likely to be very hot with the last week of August signaling the start of the temperature decline as Asahikawa heads into Autumn.
Autumn
Early morning and late night starts to be colder even though the daytime temperatures are quite pleasant. Take a back-up layer in September and you'll need a winter jacket from October (evenings). It often snows in November so if you are here then, be prepared to encounter the first snow of the year.
Winter Driving
Buses are an easy and inexpensive way of heading to the mountains from Asahikawa, but some prefer the hands-on approach that comes with driving themselves. This is easy enough provided you bring your international driver's license with you and manage not to lose your passport along the way.
The road conditions are generally very good as a result of the meticulous snow clearing operations on the part of the city and surrounding towns but can become difficult quickly.
The majority of roads are un-salted so for the entire time you will be driving on snow or ice on snow tires.
This is not altogether difficult but can be tense for first timers. Really, it does not take long to get used to but remember that initially you will be facing foreign signals and road signs and this can be a little distracting.
Note also that during winter some smaller roads may be permanently inaccessible. Try to stick to main roads when possible.