Boston, Massachusetts.

Historic Boston is now a very heavily populated areas.

Boston shows rising low temperatures for 9 out of 10 months. The change in the high temperatures is a little less predictable.

March and December show the most heating in Boston with both high and low temperatures rising about 0.4'F per decade. For December the purple line indicates that low temperatures once fluctuated around 24'F. Since 1990, low temperatures have remained above 24'F except for December 2000.

The green line shows the changes for March's high temperatures. Before 1972, March high temperatures remained below 44'F most of the time. After 1985, high temperatures remained above 44'F most of the time.

October shows the other extreme. Both low and high temperatures are dropping at about 0.2'F per decade.