A one-dollar rent decline hides a two-speed apartment market

CoStar Group’s Apartments.com national rent index slipped a dollar in August to $1,751, a 0.03 percent decline from July’s upwardly revised $1,752 and the first monthly drop after eight consecutive increases. A dollar is a rounding error. The season it arrived in is not: late-summer dips have now shown up every year since 2024, with August 2024 down 0.1 percent, August 2025 down 0.2 percent, and this August’s decline contracting to 0.03 percent, which the report reads as an improvement in pricing conditions.

That national print flattens a wide spread: thirty-one of the top 50 markets cut rents month-over-month in August, seven were unchanged and 12 posted increases. The monthly strength came mostly from California, where Orange County rose 0.6 percent, San Francisco 0.4 percent, the East Bay 0.3 percent and San Jose 0.2 percent, matching Chicago’s monthly gain. Over twelve months San Francisco is the standout at 11.9 percent and San Jose second at 7.7 percent, while the Pacific Northwest and the Midwest lead the regions at 2.2 percent apiece and the Northeast follows at 2 percent.

That dispersion follows supply. The report says most markets have moved past peak construction, but a substantial—though gradually easing—inventory overhang continues to moderate rent growth nationally as the summer leasing season closes. Concessions thinned for a second straight month in August, first-half construction starts hit their lowest level since 2012, and in Queens CoStar put vacancy at 2.08 percent against a decade-low pipeline.

For an apartment buyer, the national average is now the least useful number in the report. It blends 31 markets shedding rent with a handful of coastal metros compounding annual growth, and it says almost nothing about the building in front of a diligence team. The operator, not the asset, is the underwriting unit this cycle; August adds a corollary: supply is still the swing factor setting price in most metros, so the work that pays is market-level pipeline timing and a sponsor’s lease-up record, not a rent-growth assumption lifted off a national series.

San Francisco at 11.9 percent and those markets cutting rent can both be true for a while. Starts and lease-up time will announce which one turns first, and buyers who price that gap instead of the average are making the better bet.