Western Sydney is forecast for a string of hotter than average days, before a cool southerly change. This run of hot days is forecast for western Sydney from tomorrow as a warm air mass establishes itself over the state. Penrith is forecast to record a string of four days above or equal to 33 degrees, if it happens it will be the longest run equalling or above 33 degrees during October in at least 19 years. On top of this, Penrith is likely to reach 38 degrees tomorrow. If this eventuates it will be the hottest October day in just under a decade. Currently, a total fire ban is in place for the Greater Sydney region until at least tomorrow. The good news for fire fighters in the Sydney region is that gusty northwesterly winds that we saw last week will not be as strong. On Wednesday 23rd, an approaching trough will create stronger northwesterly gusts in the morning before temperatures drop after the cool southerly change. It will be cooler on Thursday and Friday under the southerly winds, with the mercury hovering in the mid-twenties in the city and the high-twenties in the west.