Baie-James is in Canada.
The weather seems to vary quite a bit. In June of 2009, it was hot (80F) during the day and cool (50F) at night. It would be best to be prepared for colder weather, as June nighttime temps in the 30's F are not uncommon. Hot temperatures present more of a challenge than cold temperatures. You must have some kind of bug protection, and in hot temperatures, one must find a way to keep cool while inside a bug screen of some kind. In a vehicle, about the only way to be comfortable is to keep driving with open windows. Luckily, there are frequent rivers which while somewhat chilly, are good for swimming.
Visit a Cree community. Chisasibi has a paved road to the village, however Chisasibi is somewhat industrial. It is not the best village to learn about Cree life and culture. There is a gravel road from Chisasibi to the James Bay Coast. When you near Chisasibi, do not take any of the side streets, and follow signage to the barge. As you approach the barge site, take a left and continue on to a boat launch. Most boats there are freighter canoes.
Wemindji is an excellent location to observe a Cree village. One must travel 96km of gravel road from the James Bay Road to Wemindji. In 2009, there was an exhibit of how the Cree tipis were constructed near the boat launch in town. Wemindji appears to be a prosperous town with a great deal of construction. Wemindji is surrounded by islands and a chain of lakes that are connected to James Bay.
North of Chisasibi is Longue Point, a dramatic location which appears to be the furthest north that one can drive to the coast of James Bay. It is a launch site for freighter canoes and in winter is a starting point to snowmobile on the ice of James Bay. To find Longue Point, cross the LeGrande 1 dam near Chisasibi and follow the gravel road to the end. This is truly the end of the road and about as far as you can drive north along the bay.
Fishing in the rivers and lakes along the James Bay Road is permitted with a Quebec fishing permit. In the areas surrounding the Cree communities, one must have a guide to fish. Generally there are signs in areas where fishing is prohibited to non-natives.
There are grocery stores in Matagami and Radisson. There is a grocery store in the center of Chisasibi. There may be grocery stores at Wemindji and Relais Routier. When entering the James Bay region, you must carry enough food and water for several days (minimum). Most campgrounds have no water wells. You may wish to take water directly from the rivers. A pail with a rope tied to the handle makes fetching water from rivers much easier.
There are a number of official and unofficial campsites along the highway which as of 2009 were free (with a requested donation of $5 per day). The official campsites will typically have a picnic table and pit toilet. Many of the official campsites are located near rivers or lakes, and in some cases are next to beautiful waterfalls. Most campsites are gravel, which is not particularly suited for tenting. If you plan on tenting, take a sturdy groundcloth. There are numerous logging roads and turn-offs that one could take and overnight in the wild along the way. A self contained camper van or motorhome are ideal for travel in the James Bay region.