David Silbey has a chart showing deaths among coalition forces in Afghanistan (click to enlarge):
The worst month for coalition forces in Afghanistan was July 2009, when 77 fatalities occurred. That month still does not rival the worst months of Iraq (141 in November 2004 and 131 in May 2007), but each summer and each winter has seen a higher number of fatalities, and January 2010 is, only 12 days into the new year, already the second-worst January of the war.
The Dish 