Wildlife viewing seasons are:
From the end of May to mid June:   birds, birds and more birds (over 200 species).
June and July: lots and lots of wildflowers
July to mid August: Beluga Whales, wildflowers, goose berries, wild blue berries, soap berries.  Lots of snow geese.  Polar Bears can also be seen.

Mid-October to mid-November: Polar Bears.

August sunsets are truly spectacular. The sky looks like it is on fire.

Northern Lights can be seen any time of the year, although the best time is January and February since the skies are usually clear (unlike the spring and summer).    Northern lights can be seen in August. Colours are not as intense as in the winter. Best to photograph using a digitial camera with manual settings, and a fast wide angle lens.  Tripod is mandatory as you'll be shooting long exposures in excess of 10 or even 20 seconds.

Churchill is surrounded by both tundra and taiga. The shores of Hudson Bay are also covered with large greywacke rocks. The Churchill Northern Studies Centre offers courses of many different interests.
North Star Tours offers a day tour that covers the entire area and the history and wildlife surrounding Churchill.   The tour starts at 9 a.m. and continues until about 3.
Note:   The original information for this thread came from the    following forum thread:  
http://www.tripadvisor.com/ShowTopic-...