Weather in Tokyo and Osaka in January
 

Is it too cold to tour these cities in December, January or February?

It will be cold with highs around 45 and lows around 30. Little snow.

December is actually quite a good month. It's cool (not cold*), and it's one of the driest months of the year.



* "not cold" can, I suppose, depend on what you're accustomed to.

Jan-Feb are the colder months.....as DT says cold is relative....to me its freezing in Jan-Feb.

http://www.japan-guide.com/e/e2273.html

Aloha!