The warm weather is set to stay in Edinburgh "well into" September, say Met Office forecasters.
Forecaster Stuart Brooks also said temperatures could reach up to 21C today in the capital, with mostly clear skies.
And he said the mercury could hit 22C on Sunday despite it being much cloudier.
Mr Brooks added: "There is a band of high pressure setting up to the east of us. It's certainly a very favourable outlook which looks like it might last well into the month."
He said the first part of tomorrow will be clear but cloud is forecast for later in the day, although temperatures are still expected to hit 18C. West Lothian could also get some light rain.
After a warm Sunday, temperatures will stay fairly high between 18C and 19C for both Monday and Tuesday, dropping slightly to about 16C for the rest of the week.