A trough brought a cooler change to southern parts of Victoria overnight but there will be no relief for the state's north. Temperatures soared across Victoria on Friday, reaching the low to mid 40s across the state's north and through much of the south. The hottest parts of the state were the Mallee and Wimmera, where Walpeup, Mildura, Ouyen and Horsham all maxed out near 44 degrees. It also reached 44 degrees in Dartmoor and Sale, their hottest days in three and four years respectively. It was more than 20 degrees above average in parts of the West Coast, with 42 degrees at Cape Nelson and Portland, and 43 degrees at Port Fairy. Portland hasn't had a hotter day in 30 years. Melbourne reached a stifling 41.1, making it their hottest day since December 2010. Temperatures then lingered in the mid to high 30s until midnight. A southwesterly wind change arrived early in the morning. This allowed it to cool to 23 degrees just after 3am, bringing some relief to restless sleepers. It will be a much cooler day for southern parts of VIC today, with temperatures reaching the mid to high 20s this weekend before heat builds again on Monday, bringing more scorching temperatures. It's a different story for the state's north though, as an extremely hot airmass lingers over the region with extreme heat set to continue until at least the end of next week. Mildura is forecast to exceed 40C each day until Tuesday, which would make it six days of above 40 degrees. This would be their longest heat wave since February 2009 when Black Saturday occurred and they had 12 days in a row.