Coming from the States for many year. I remember the good old days too... when exchange rates were 1USD=1.20+CAD. Hell, as much as 1.40+. I also remember when US visitors used to get a Tax Rebate on sale taxes and hotel taxes. Sniff... sniff. The great USD to CAD exch made really great MTL restaurants "cheap".
For the most part the reason for the bad USD to CAD is simple. Price of OIL. And the price of oil as it relates to the US Stock Mkt. If the US Stock Markets are UP, more than 90% of the time the USD to CAD exchange rate down. Why? A good US Stock Mkt is perceived by oil speculators as a higher demand for oil and hence a lower USD to CAD exchange rate because of the price of oil.
You will notice that on a given day, if the US Stock Mtk is UP the USD to CAD is DOWN; and the other way around. There is usually an inverse relationship, but once in a while other factors can tip the fluctuation the other way (both UP or both DOWN).
With the US QE3 that someone mentioned in a previous post, the best us poor US visitors can hope for is EVEN rate. If you can accept that EVEN is Good, a swing in the exchange rate of of $3 or $4 below the CAD really is not that significant. So if you spend $2000USD, you are under $80. C'est la vie.
Someone I used to work with used to say, "Can't put a price on a good time". OK. Maybe you can.