These are the conditions which result in a sheep graziers alert being issued. Losses of 50% to 70% can, and have occurred in flocks in the past.
The most important thing to guard against this, is to provide shelter, we have found that as unproductive as Poa tussock is, it provides a very effective windbreak for the young lambs. Tree lines and slopes where the sheep can shelter on the leeward side, are also beneficial . Here on the Southern Tablelands, graziers alerts seem to be able to occur at any time of the year.
Research has also shown, that both sheep and cattle, put on more weight, when provided with shade during the hot summer months. So when planning your paddocks it is well worth considering these issues.