MINNEAPOLIS — The call is going out for blood donors in Minnesota and Wisconsin.

Memorial Blood Centers said its supply of O-negative blood is dangerously low across its 11 donor sites in Minnesota and Wisconsin.

Spokesman Larry Silber told Minnesota Public Radio News the organization has been able to keep up with the demand for O-negative blood so far, but more donors are urgently needed. A combination of cold weather, vacations and the flu season has led to the decrease in donations.

The shortage is particularly critical because O-negative is a universal blood type that can be used in emergencies.

But O-negative donors are also rare. According to the American Red Cross, only 7 percent of people in the U.S. have O-negative blood.

To learn more about donating blood and to schedule an appointment, download the Red Cross Blood Donor App, visit redcrossblood.org or call 1-800-733-2767.

Upcoming Mower County blood drives

March 9, 2 to 7 p.m., at Our Savior Lutheran Church, 411 West Main St. in Brownsdale.

March 10, 11 a.m. to 5 p.m., at Grand Meadow School, 710 4th Ave. NE in Grand Meadow.

March 11, 10 a.m. to 3 p.m., at Riverland Community College, 1900 NW 8th Ave. in Austin.

March 12, 1-7 p.m., at Southland High School, 203 Second St. in Adams.

March 13, 11 a.m. to 5 p.m., at the Community Center, 204 W. Main St. in LeRoy