$$$$$$$At which time of the year is the Dollar lowest?$$$$$$$$?

Answer 1

When the economy is bad. So all year round.

Answer 2

The only pattern on Yahoo! Finance 5 year Euro vs. dollar chart that I can see is that there is always some sort of dip in the middle of the year. Other than that, I don't see an annual pattern. Take a look for yourself...
http://finance.yahoo.com/q/bc?s=USDEUR=X&t=5y&l=on&z=m&q=l&c=