The mercury is soaring in Sydney today, but tonight's weak cool change won't shake western suburbs free from their hottest November spell in decades. Gusty northwesterly winds are dragging very hot air from the nation's interior into eastern NSW, including most of Sydney. The city originally raced to 34 degrees by 10am before a weak southeasterly wind put a lid on the rising temperature. Almost everywhere further west the temperature is still rising towards 40 degrees. Brief relief from the heat is on the way, with the first in a series of three troughs bringing a cool change around dinner-time tonight. Unfortunately for the western suburbs the cool change will only drop temperatures slowly this evening ahead of a peak in the low-to-mid 30's on Saturday. On Sunday the heat will be on again with an even hotter airmass taking control of the Sydney area. People will be going to great lengths to keep cool; with some heading to the beach, some to the cinema and some will just stick their head in the freezer. Those closer to the coast will get the first hints of relief with a seabreeze developing during the middle of the day. Again the cool change will be weak, arriving during the evening hours and only taking a bit of the sting out of the warm night. By Monday many people will be thoroughly sick of the heat, with humidity increasing all the more. Thankfully the cool change in the middle of Monday night will bring a significant cool change meaning that the Western suburb's hottest five-day November run in at least two decades will be over with tops of only 27 degrees on Tuesday.