Average retail gasoline prices in Washington have fallen 5.2 cents per gallon in the past week, averaging $3.73 per gallon on Sunday, according to GasBuddy's daily survey of 2,666 gas outlets in Washington.

This compares with the national average that has fallen 0.4 cents per gallon in the last week to $3.57 per gallon, according to gasoline price website GasBuddy.com.