Does weather affect the train schedule

Usually NO. But it depends on how bad the weather is ...

Extreme weather will affect the schedules of the trains coming in and out of Grand Central Terminal. Sometimes extreme weather can also affect the NYC MTA Transits schedules.

Depends how bad the weather is

Yes! Trains will be affected by various types of weather, particularly snow! But also torrential rain, winds, leaves.

Normally - no

The operation is the same every day