Yesterday was a scorching 39.4 degrees in Melbourne yesterday - this was the hottest day this late in the season since March 1998. This year may not be entirely co-incidental; 1997-1998 was one of the strongest El Ninos on record, similar to the recent 2015-2016 El Nino conditions. The heat originated from the nation's northwestern interior. An inactive monsoon has kept this area relatively cloud free, causing hotter-than-normal conditions to occur later than normal. As the dry heat was funneled to the Melbourne area ahead of a low pressure trough, it caused a spike in fire danger. This prompted authorities to release a total fire ban across the state yesterday. This was well-warranted; an out of control fire started yesterday afternoon just to the northwest of Ballarat at Mount Bolton, but was later contained. A total fire ban remains for the Mallee, Northern Country, North Central and North East, all of which have potential for Severe fire danger today. As the hot northerlies rapidly gave way to cooler southerly winds, temperatures plummeted eight degrees between 5pm and 6pm. Although this initially brought some relief, temperatures struggled to drop further into the evening. At midnight it was still 24 degrees, which is only about a degree less than the average daytime February maximum. The minimum came just before 4 o'clock this morning at 22.4 degrees; making it the warmest night since December. Elsewhere around Melbourne, Avalon dropped to 22 degrees, its warmest February night in 16 years, while Laverton and Moorabbin cooled to just 23 and 22 degrees respectively, their hottest February night since 2007. A more significant cool change will roll through Melbourne tomorrow afternoon, dropping daytime maximum temperatures to 23 degrees by Friday, before it warms up this weekend.