One of Wellington’s warmest days this summer caused commuter chaos and delays last night.
Train services on the northbound Johnsonville line were cancelled from 5.30pm after a section of track near Crofton Downs, the first stop, buckled because of the heat.
Services were back up and running as usual this morning.
Last night's service, which runs every 10-15 minutes during peak hour, had to be replaced by buses.
Some passengers were taken by road to Ngaio, the second stop, where they boarded the train for the remainder of the journey.
Instead of the usual 22-minute trip to Johnsonville, it took some passengers mored than 40 minutes to make the trip.
After the busy commuter period was over, trains were completely replaced by bus services so contractors could carry out "essential track maintenance".
Tranz Metro, which operates the service for Metlink, normally carries thousands of passengers every night.
Yesterday's temperature in some parts of Wellington reached 26 degrees. A slighter cooler 23 degrees is forecast today.