ScotRail is reopening platform two at Troon station on Monday July 26, though platform one is not scheduled to reopen until later in the week.
The station was hit by a blaze on July 17.
Platform one is scheduled to reopen on Friday July 30, when trains between Glasgow Central and Ayr will return to normal operation.
ScotRail operations director David Simpson said: “We regret any disruption to services because we know how it will inconvenience our customers.
“However, the dreadful fire at Troon station left our colleagues at Network Rail with no option but to close the line, and we had to revise our services accordingly.
“It’s great to see that we are resuming services from Glasgow to Ayr today, with a full timetable expected to be operating on Friday, 30 July.”
If passengers are travelling north, they are being advised to take a train to Prestwick Town to connect with Glasgow-bound trains.
If they are travelling from the south, the advice is to change at Irvine for connecting trains back to Troon. There will be no shuttle buses.
ScotRail said Network Rail has fully assessed the damage to the buildings, platform canopies, overhead power cables and other infrastructure.
Special supports have been designed and installed on platform two, which enabled track-level repairs to be carried out, and similar props on platform one are supporting the beams over the tracks to which overhead line equipment is attached.
New overhead power cables have also been installed.