Tucson's average gasoline price fell 4.1 cents a gallon in the last week, to a $3.21 average, continuing a month-long trend, GasBuddy.com reported in a press release Monday.

The price decline belies the national trend, which showed a 1-cent a gallon increase in the last week, to $3.51, GasBuddy.com reported.

"The national average has begun to tip-toe higher in the last week, led by states in the Great Lakes and West Coast, where gasoline prices have crept up considerably in some areas over the last week," GasBuddy.com Senior Petroleum Analyst Patrick DeHaan said in the press release.

The average price is based on a survey of 328 outlets in Tucson. In the last month, Tucson gasoline prices have fallen 19.5 cents, the report said.