CLIMATE
There are very definite seasons here in Gifu-ken with weather being similar to the Pacif Seaboard of Japan.  This description is for the Gifu City and Ogaki area.  For people who live more north just imagine similar weather conditions except that the cold will be stronger, come earlier and stay longer.

WINTER
December to February are cold winter months.  There are a few snow storms, but snow is not constant.  The days tend to be clear and sunny, just very cold.  The temperature may not be that low, maybe -5 Celsius at the lowest, but 2 things make it seem colder.  One, is there can be a very cold wind that makes you feel like an ice-cube biking to school.  Two, many - perhaps all - apartments do not have central heating.  For example, I am able to see my breath in rooms where I do not have a heater set up.  The following are options for you to warm yourself up:
1) Kerosene heaters - there are some good ones and bad ones.  Good ones have time settings, a fan, and do not give off a kerosene smell.  It is recommended to have a window cracked a bit if you are using a kerosene heater.  You can buy the kerosene from a gas station for cheap.  When you first start up your kerosene heater, after its been sitting in the closet since last year, it is good to start it up and shut it off in a room you do not use much or to take it outside right after you finish with it. Some heaters are very stinky at first.
2) Air conditioners - you can buy ones that provide both heat and AC.  They can cost from about 50,000\ for an entry level wall mounted unit, to have it installed will cost at least 20,000\ or 30,000\. Installation costs will depend on you apartment setup.  They are supposed to use a lot of electricity and usually can only heat one or two rooms.  But, it is great to just push a button to control the temperature.
3) Kotatsu - this is a low square shaped table that has an electric heater attached to its underside.  There are special comforters that you put over the table to keep the heat in and you sit with your legs - or body - under it.  It is not recommended to sleep under it, but I know people who did and lived.
4) Electric space heaters - can cost from 10,000\ up; some only heat a small space versus your whole room.
5) Electric blankets and carpets - A cheap blanket can cost about 4000\ and a cheap carpet around 9000\.
We make a lot of money, so you will have to decide what your cold tolerance is to your save money needs.

SPRING
It starts to warm up slowly in March, and you can enjoy cherry blossoms and warm comfortable weather from April to May.  This is a nice time to travel, albeit many other people think so too.  We have Golden Week at the start of May, which is a time when just about everyone in this country gets holidays.  It is good to book ahead and make reservations for this time.  As well, if you were thinking of missing the crowd and travelling outside of Japan it will cost you about two times as much because so many peopleare also exodusing the country.

SUMMER
It starts to get hot and humid by June and you are sticky sweaty hot for July and August.  Rainy season is in June and July.  Typhoon season is in August and September.  You will want to have an electric fan, and you will suddenly see the purpose in carrying around a paper fan in your backpack.  Having an air conditioner, or knowing friends who do, will also seem like a great idea. Not only are you hot and sweaty - but everything is - this is when food spoilage, mold, and bugs can pop into the picture.  Make sure to read your expiration dates and make sure things are refrigerated.
Even things that are refrigerated do not last very long.  Mold is a big problem in enclosed areas that do not get much air.  You can be preventative and buy - or make your own solution of one part water to four parts alcohol - to wipe down walls and cupboards that may be susceptible to mold.

FALL
It is a pleasant season of light sweater-wearing days.  It is a great time to sightsee and enjoy the many colors of the fall leaves.  Fall sets in around September and goes to early December.  September is a rainy season and there maybe some days off work due to typhoons in early September.  It is dangerous to go out during a typhoon, the winds may not blow you over, but they can blow everything else around you down and potentially these falling articles can squash you like a bug.