Every year in March and April, ward offices are expected to be crowded. This is because there are many people who move, get employed, or retire from work in the spring, and many of them need to complete procedures. In particular, Mondays and the first week of April are very crowded.
If you need to complete procedures, please do so at your local ward office as early as possible.
Congestion Forecast Calendar of Ward Offices/ City of Yokohama