Police have said the Mountain Road is closed from Ramsey to the Creg-Ny-Baa.
The force says it’s received reports of ‘one rider off in poor conditions/visibility’.
It added that ‘the visibility is so poor, the one rider off might not have been seen by those travelling behind them’.
The A18 Mountain Road will now be closed until conditions clear up, with the Roads Policing Unit monitoring conditions and re-opening the route when safe.
An update will be made at 1pm this afternoon as to whether the road can open.
The weather forecast from Ronaldsway Met Office says while it’s wet this morning, the rain and drizzle will clear away early afternoon.
The rest of the day will then be mainly dry with sunny intervals, although with also a risk of one or two sharp showers during the evening.