Melbourne is enduring record heat, but this afternoon those only in t-shirts will feel the chill. Yesterday Melbourne had its hottest day this early in the season on record, reaching 34 degrees. Today has broken the record again, reaching 35 degrees at 1pm. If it exceeds 35.4 degrees it will be the hottest pair of October days on record. This is staggering considering we are so close to the start of the month. Change is in the air, and most Melburnians know it. Powerful northwesterly winds are often a precursor to a cold change and today's change will be more than noticeable. Around 3-4pm today the temperature will plummet from close to 35 degrees to about 20 degrees in the space of an hour. By 9pm the temperature will be near 15 degrees in the city. As workers leave the office many will initially rejoice with the less oppressive temperatures, but not too long after will be rummaging in their bags for the non-existent second layer. The southwesterlies will initially be just as strong as the current northwesterlies, adding noticeable chill to the air. Tomorrow the temperature will only reach 18 degrees. However from Friday each day will be above the October average of 20 degrees, but nowhere near the heat of the last few days.