BOSTON — Gas prices in Massachusetts are up by three cents.

AAA Northeast said Monday that the price of self-serve, regular is averaging $2.21 per gallon. That’s seven cents below the national average for regular unleaded of $2.28.

The price of self-serve, regular was averaging $2.14 a year ago at this time.

AAA found self-serve, regular selling for as low as $2.07 and as high as $2.41 per gallon.

AAA officials say “a continuing global glut of crude oil has helped keep gasoline prices in check.”