The temperature in the 1500m loop is 17 degrees. In the creek it’s 15 degrees as it’s shaded. There is a 100m swim out to the start so you’ll be able to acclimatise.
Please make sure that all your kit, wetsuits and equipment is completely dry before entering the water. Unfortunately there’s been a suspected outbreak of Crayfish plague on the Cwm y Caddo, a tributary of the Monnow, and it’s essential that this isn’t spread elsewhere. It’s carried as spores on wet kit and in mud.