The Simplyhealth Great South 5k and the Junior and Mini Great South Run events, which were scheduled to take place on Saturday 21 October have been cancelled.
The latest Saturday forecast in Portsmouth and Southsea received at 17:30 on Friday predicts strong winds with gusts in excess of 50 mph and heavy rain, making conditions unsuitable for participants.
The Simplyhealth Great South Wheelchair Event that was part of the Saturday programme has also been cancelled.
The Simplyhealth Great South Run, due to take place on Sunday 22 October is currently scheduled to go ahead as planned, with an improved forecast.
Organisers are in the process of contacting all entrants by email and SMS text message with further information.
David Hart, Communications Director at the Great Run Company, said: “We understand this will be disappointing news to the 3,000 adults and children who were planning to take part, but the safety of participants, spectators and of all those associated with the staging of the events is always our number one priority.
“We thank everyone who will be affected by the cancellation for their understanding.”
Entrants can find the most up-to-date information available on the Simplyhealth Great South Run website: Greatrun.org/South