Almost the entirety of Melbourne Metro has been slowed by Friday’s heatwave, with speed restrictions taking effect and causing delays of up to 15 minutes.

All lines except for Stony Point are currently affected, as the Age reports.

As of 5.30pm the Craigieburn line is the worst affected and is experiencing major delays.

Earlier in the day the Williamstown and Lilydale lines were also issued major delay alerts but these have been downgraded to minor delays.

Check for updates.

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