Reis reported that the apartment vacancy rate was at 5.3% in Q2 2021, unchanged from 5.3% in Q1, and up from 4.9% in Q2 2020. The vacancy rate peaked at 8.0% at the end of 2009, and bottomed at 4.1% in 2016.
Click on graph for larger image.
This graph shows the apartment vacancy rate starting in 1980. (Annual rate before 1999, quarterly starting in 1999). Note: Reis is just for large cities.
The vacancy rate has increased somewhat from the low in 2016.
There are other surveys that suggest the apartment market has tightened recently. The NMHC reported that their market tightness index hit an all time high in July. There are other indicators that suggest the vacancy rate is moving lower.
Apartment vacancy data courtesy of Reis.