Metrolinx has advised that it is further reducing GO Transit service starting January 22 to better match customer demand. They are reducing some rail and bus service, replacing some GO train service with buses, and adjusting some schedules.
Here is a summary of modified service on the Lakeshore West line. Hourly service to West Harbour will be still maintained seven days per week, and there will still be some trips out of the Hamilton GO (Hunter St.) Station:
On weekdays, during the morning rush hour, eastbound trains will depart every 30 minutes or better from Aldershot GO to Union Station. During the afternoon rush hour, westbound trains will depart every 30 minutes or better from Union Station to Aldershot GO.
From Hamilton GO Centre, there will be two weekday morning eastbound rush hour departures and two afternoon westbound rush hour return trips from Union Station.
From Niagara Falls, there will be one weekday morning eastbound rush hour departure and one afternoon westbound rush hour return trip from Union Station. The westbound trip will depart one hour earlier, at 5 p.m.
Through the day, off-peak trains will depart every 30 minutes between Aldershot GO and Union Station. In the evening, train service will run hourly.
Trains will run hourly between West Harbour GO and Union Station all day.
On weekends, service will run hourly between West Harbour GO and Union Station, making all stops.
Weekend train service to and from Niagara Falls and St. Catharines (Fairview Mall) will continue to be replaced by GO Bus Route 12, which connects with trains at Burlington GO.
More details are available here: https://blog.metrolinx.com/2022/01/06/metrolinx-adjusts-go-transit-schedules-due-to-covid-staff-impacts-allocating-resources-to-provide-consistent-service-across-the-network/
Metrolinx is continuing to closely monitor staffing levels and ridership and will provide as much notice as possible if additional changes to service are required.