British Columbia, Canada (BC) is north of Washington/Idaho/Montana.
I download monthly data from the Environment Canada (EC) websites. EC treats some stations as special and calculates anomalies against what they call Normals. As of today the Normals are calculated for 1971-2000 and I am using those special stations. This data is in anomalies in Celsius, not Fahrenheit. Here, for example, is data for all of Canada for Aug 2012 (I am just looking at BC today).
British Columbia has been cooling at -0.501C per decade for last 15 years.
Click on the graph for full size.
Another way to look at the data is to calculate 5 year means going backwards from the most recent data.
The most recent 5 year period in BC is -0.01C colder than the 1971 – 2000 Normals.
More importantly it is .79C colder than the previous 5 year period. That also puts the last 5 years colder than ~1925-1930, and colder than ~1940 and the same temperature as ~1960 and ~ 1990.