The climbing season for Mt.Fuji
The climbing season for Mt. Fuji is from early July to early September. The recommended season is after the rainy season was over, because there are many rainy days when it cannot expect the view very much until the end of the rainy season of July . But it is necessary to be careful about typhoons. Because there are not things to block, Mt.Fuji is easy to be affected by the typhoon. Therefore you need to attend more necessary than level ground.
It is crowded on weekend and “Obon” week which is Japanese holiday
At the weekend and the holiday when the weather looks good, most people come to Mt.Fuji.
I think that you should avoid “Obon” week and the weekend if you avoid congestion even a little. I recommend that you climb Mt.Fuji until closing Mt.Fuji day of September if you climb Mt.Fuji on the weekend. Crowding is more relieved than July or August.
To take a bus to the 5th station
The easiest and cheapest way to trail head is to use the direct bus from Tokyo to Fuji Subaru Line 5th station. (trail head of Yoshida track). Next choice is going to Kawaguchiko Station by bus or train and then take the bus to 5th station. Anyway, Yoshida track is the easiest way both of approach and climb. About other 3tracks, train and bus are operated on climbing season, too.