Melbourne is set to swelter through 3 big nights of hot weather as summer finally seems to be arriving.

Temperatures will start to rise in the city on Tuesday, when a high of 29 is forecast but strangely, Wednesday will be slightly colder at 27 degrees.

However, come Wednesday night, a minimum of 13 will be a bit warmer than usual and will lead to a high of 33 degrees on Thursday.

Thursday night will be a doona-less night, as we head to a low of 18 before a top of 34 on Friday.

We are likely to see a late shwer on Friday which will mean a cooler night that leads into a annoyingly cool weekend, with Saturday and Sunday not getting above 24.

For Derby Day on Saturday at Flemington, there will be a chance of rain in the morning but it should brighten up.