Cities below are listed in descending order of population. It is interesting that, in general, trend line slopes become conspicuously more negative as population decreases.

For example, compare July temperatures between Minneapolis and Faribault.

MAXTMP Temperature Trendlines (Linear Least Squares)
Minneapolis, MN: 1950 - 2002
Rochester, MN: 1948 - 2002
Faribault, MN: 1948 - 2002
Atlanta, GA: 1950 - 2002
Athens, GA: 1948 - 2002
Albany, GA: 1948 - 2002
Phoenix, AZ: 1948 - 2002
Tucson, AZ: 1949 - 2002
Prescott, AZ: 1948 - 2002
Winslow, AZ: 1948 - 2002
Richmond, VA: 1948 - 2002
Lincoln, VA: 1948 - 2002

Summary (Discussion, Tables and Plots)

As Population Decreases, Trend Line Slopes Become More Negative:
Global Cooling.pdf
Camilla Addendum.pdf