Claire Bolton died after a 50ft ash smashed through the windscreen of her car as she drove down a country road near Hawkhurst, Kent, in January this year.
The tragedy occurred after a period of heavy rains across southern England, the inquest at Hasting Magistrates' Court heard.
According to a report in the Daily Telegraph, the inquest heard how the tree, which was on private property, had been deemed healthy by tree surgeon Mark Cruttenden.
But forestry officer Andy Piper said the fall was caused by a build up of water surrounding the roots and heavy winds battering the tree.
Piper, who works for East Sussex County Council, said no one could have predicted the tree would fall when it did.
"The roots were waterlogged and with the gusting winds from the day before that had just come over, it would have been the wind that caused it," Piper said.
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