Low cloud and fog has caused a lengthy delay to Tuesday's TT schedule.
The solo warm-up lap will now take place at 1.30pm, followed by the sidecar shakedown at 2pm.
The three-lap Superstock race one will take place at 2.45pm.
Roads, except the mountain section, will then open at 5pm, shutting again at 6pm.
The first three-lap Supertwin race of the week is then planned to take place at 6.30pm.
The whole of the Mountain Course closed at 10am as planned and remains shut. Crossing points will be open until 1.10pm.