A Con Ed rate hike that kicks in next week could be the first noticeable bump in New Yorkers’ electric bills in three years.

Expect about a 4 percent boost in electric costs starting April 1, when the second year of a three-year rate-hike plan approved by the state last year takes effect.

New York City apartment dwellers who now pay $87 for 300 kilowatt hours per month will see their bills jump to about $91, Con Ed estimates.

That estimate assumes no change in the cost of natural gas, oil and other fuels used to generate electricity. Con Ed customers could end up paying more — or less — depending on what happens with fuel prices.

Con Ed got state-approved rate increases in 2009 and 2010 to cover its costs of delivering electricity from generators to homes and businesses.