A wave of exceptionally hot weather has blasted the region over the past week, sending the mercury as high as 45 degrees Celsius
Final practice for the Russian Formula One Grand Prix was cancelled due to heavy rain in Sochi on Saturday.
If the weather doesn’t improve, even the qualifying session is at risk of being postponed until Sunday.
Race stewards said in a statement that the decision had been taken for safety reasons.
The session had been due to start at 1200 local time (0900 GMT) with qualifying at the Olympic Park scheduled for 1500 local (1200 GMT).
A Formula Three race that was originally scheduled for Saturday morning was held on Friday, with the title won by 18-year-old Norwegian Dennis Hauger, and a Formula Two race postponed.
Formula One’s governing body, the FIA, said it expected the local airport to reopen before the scheduled qualifying time, allowing the medical helicopter to resume operational flying.
“From what we are seeing from the forecast side...we will have sort of this level of rain until about 1.30 to 2pm local time and then it decreasing in the afternoon,” said race director Michael Masi.
“The priority from today’s perspective is obviously Formula One qualifying this afternoon, so Formula One will take priority.”
Masi said the light would be the determining factor in how late qualifying could be postponed until.
“Sunset locally is about 1815...but with weather conditions like this obviously (the) light diminishes far earlier,” he added.
“If qualifying isn’t able to happen today, as we’ve seen a few times before in the past, then we will redo the programme and hold qualifying on Sunday morning.”
Red Bull’s championship leader Max Verstappen is set to start from the back wherever he qualifies due to an engine change.
Mercedes’ title rival Lewis Hamilton will be looking to overturn the Dutch youngster’s five-point advantage with what would be a record-extending 100th career win.
Mercedes have won every Russian Grand Prix in Sochi since the first in 2014 and Hamilton’s team mate Valtteri Bottas, last year’s race winner, has said he will obey team orders if necessary.
A wave of exceptionally hot weather has blasted the region over the past week, sending the mercury as high as 45 degrees Celsius
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