Apartment owners in Lake Forest sought the biggest rent increases in the county over the past year, while landlords in Cypress barely raised their rents at all.

The asking rent for an apartment at Lake Forest’s 13 largest complexes went up an average of $199 a month in the year ending Sept. 30, according to a report from apartment tracking company Real Answers.

The Lake Forest jumbo jump was almost double the countywide increase of $102 a month. The average rent at Orange County apartment complexes with 90 or more units now stands at $1,867.

Lake Forest wasn’t the only place where rents rose dramatically. Rents also jumped in Mission Viejo ($186), Huntington Beach ($182) and Stanton ($162).

Conversely, the average hike at the biggest apartment complexes in Cypress was just $6 a month.

Rents have been rising throughout the county for almost five years. Real Answers reported rents up for all local cities for the past 18 months.

Generally, rent hikes are bigger in South County, though apartment owners in Newport Beach and Irvine, the two cities where rents are already the county’s highest, asked some of the smallest increases.

Experts offered different theories about why rents are rising more in some cities than in others.

Nicholas Dunlap, president of the Apartment Association of Orange County and a local property management executive, described a rent-increase pattern based on proximate geography.

For example, Dunlap said, renters might be moving to Huntington Beach to escape sky-high rents in Newport Beach, where last summer the typical vacancy had an asking monthly rent of $2,397.

“People who want value, they are going to neighboring markets,” Dunlap said. “Demand is spilling over from neighboring cities and creating higher occupancy rates. … The rents (in those cities) are going to increase as well.”

Tommy Thompson, executive director of the California Apartment Association Orange County, suggested that renters might be moving to Lake Forest, Mission Viejo and Huntington Beach to be near jobs.

“Definitely, they’re catching up (to market rents) in those cities where the job centers are,” Thompson said.

Real Answers surveyed 517 Orange County apartment complexes with a minimum of 90 units this past summer, representing almost a third of all the rental households here.

The firm reported results for only the 23 local cities with five or more large complexes.

The averages represent only what landlords were seeking from new renters, not rent hikes imposed on existing tenants.

The firm reported that the county average asking rent of $1,867 during the summer quarter was a record, up 5.8 percent from $1,765 a month in the same quarter of 2014.

In Lake Forest, asking rents for vacant apartments averaged $1,833 a month, up 12 percent from $1,634 in the summer of 2014.

Apart from Cypress, cities with the smallest year-over-year rent hikes included Irvine, up $35 a month to $2,114; Fountain Valley, up $54 a month to $1,683; Orange, up $77 a month to $1,792; and Newport Beach, up $79 a month.

Rent also was up $84 a month in Buena Park, Orange County’s most affordable city with an average asking rent of $1,459 a month.

That’s still expensive compared with much of the state.

The average asking rent for a large-complex unit in the Inland Empire last summer was $1,303, Real Answers reported. It was $977 a month in Bakersfield and $903 a month in Fresno.

Just five of 24 California metro areas had higher asking rents than Orange County.

The San Jose area had the state’s highest asking rent in the state, with big-complex landlords seeking $2,623 a month, followed by San Francisco at $2,539 a month, according to Real Answers. (A separate survey by Reis Inc. had those two cities reversed, with the state’s highest rent in San Francisco and San Jose ranking second.)

The next highest rents were in Santa Cruz County at $2,194 a month, Los Angeles County at $2,088 and Napa County at $1,880 a month, according to Real Answers.

Contact the writer: 714-796-7734 or jcollins@ocregister.com