An uptick in noise from nighttime flights has made more Minneapolis homes eligible for noise-proofing improvements such as new windows and air conditioning.

This month, residents along eight blocks in southwest Minneapolis — 137 houses and 88 apartment units — will be notified that the noise of planes overhead has been above a specified level for three years, qualifying them for the upgrades. Most of the newly affected homes are in the Lynnhurst neighborhood, near Lake Harriet, with one additional block in the far southwest corner of the Tangletown neighborhood.

They’ll now be added to the much larger list of south and southwest Minneapolis residences already eligible for noise mitigation — an indication that yearslong noise problems persist, despite the city and airport authority’s efforts. Officials say one issue is an increase in evening flights using one runway, 12R. Low-cost airlines that have entered the market in recent years are increasingly depending on off-peak-hour flights to keep prices low, and because passengers are booking those flights, other airlines are following suit.

Dana Nelson, the Metropolitan Airports Commission’s manager of noise, environment and planning, said the trend prompted officials to send a letter to airlines last year, urging them to cut back on evening and early-morning flights because of the Minneapolis-St. Paul International Airport’s proximity to thousands of homes. She said the airlines have not made any significant changes.

“It’s all demand driven,” she said. “If it doesn’t make sense to them to operate these times of day or specific aircraft, they won’t do it. They’re finding it does make sense to them right now.”

Homeowners now eligible for noise mitigation will be notified by July 1, Nelson said. The Metropolitan Airports Commission also has an interactive online map where residents can type in their address and learn whether they are included in the expanded mitigation zone. Those in affected areas will receive surveys to help officials determine what kind of improvements are needed.

In a letter to residents in her southwest Minneapolis ward, Council Member Linea Palmisano noted that many of the homes in the new zones have already received some type of improvements, though a few have not previously been eligible for the upgrades. The work is covered under a 2013 agreement under which the MAC agreed to provide mitigation to homes where noise met certain levels for three years. Nighttime flights get extra consideration in those calculations.

Palmisano encouraged residents to get the improvements, but she noted that she doesn’t see them as a permanent fix. Council Member John Quincy, the city’s representative on an airport noise advisory committee, agreed. He said the airport is seeing the use of larger planes, sometimes flying closer to the ground, and using air traffic patterns that affect several neighborhoods.

“It’s important for everybody to recognize that mitigation on homes is not the solution the city is looking for,” he said. “We’re looking to make it quieter.”