Residential electric rates fell on Oahu in May to the lowest level so far this year, Hawaiian Electric Co. reported today.

The bill for a typical household using 600 kilowatt-hours of electricity a month is $199.59 in May, the utility reported. That’s down $3.53 from $203.11 in April, and is the lowest since $193.38 in December.

The residential rate on Oahu fell to 31.8 cents per kilowatt-hour in May from 32.4 cents per kilowatt-hour in April.

Residential electric rates also fell on the neighbor islands.

Maui Electric Co. customers saw their rate decline to 37.1 cents per kilowatt-hour from 37.2 cents per kilowatt-hour last month. The typical Maui bill fell 67 cents to $231.49.

Hawaii island’s residential fell to 39.3 cents a kilowatt-hour from last month’s 39.9 cents. The typical bill fell to $246.64 from $249.63.

The rate on Kauai fell to 41.9 cents per kilowatt-hour from 42.4 cents, according to the Kauai Island Utility Cooperative.

Hawaii’s electric rates are by far the highest in the nation. The average statewide residential rate was 36.58 cents per kilowatt-hour in February, according to the latest data available from the Energy Information Agency. That was more than triple the national average of 11.61 cents per kilowatt-hour. The state with the next-highest electric rate after Hawaii was New York, where households paid 18.89 cents per kilowatt-hour in February, according to the EIA.