October in Halifax?? Actually the locals say mid October is one of the best times of the year to visit. If there is a bit of a chill in the air ("chill" of course depends on where you are from) there are plenty of local pubs with Maritime music to warm you up. On the other hand, a mild temperature is not out of the question; in which case a stroll down Barrington St. is fun and inspirational. See the Halifax Visitors Guide, and the Halifax Chamber of Commerce brochure for what to expect in Halifax, Nova Scotia.
For 30 years of temperature and precipitation data from downtown Halifax visit this Environment Canada site. Try this link for the Halifax current temperature.
New Minas Basin, Bay of Fundy