 SYRACUSE, N.Y., Aug. 17, 2021 PRNewswire -- Niagara Mohawk Power Corp. the Company, an indirect subsidiary of National Grid USA National Grid, announced that its Board of Directors has declared dividends for the period July 1, 2021 to September 30, 2021 at the following rates for all outstanding series of its preferred stock: .85 on the 100 par value, 3.40 Series; .90 on the 100 par value, 3.60 Series; .975 on the 100 par value, 3.90 Series. 