Met Office forecaster Bonnie Diamond said a temperature of -4.8C was recorded in Gogar Bank in the south-west of the city in the early hours.
A maximum temperature of 7C is expected in the capital today before dropping to 0C tonight, making Edinburgh as cold as Reykjavik in Iceland according to worldwide forecaster AccuWeather.
But the Met Office and Transport Scotland have again urged drivers to take care tomorrow morning by properly de-frosting their windscreens, windows and wing mirrors and to keep a safe distance from other vehicles on the roads due to predicted low sun conditions.
Ms Diamond said that highs of 8C are expected in Edinburgh tomorrow afternoon, ahead of another cold night.
The lowest temperatures across Scotland tonight are expected to be further inland, especially in Aviemore where it could drop to -6C.
This would make the Highland resort even colder than the city of Tromso, located inside the Arctic Circle in northern Norway, which is expecting overnight lows of -5C.
The cold snap follows on from a very cold night across most of Scotland which left many workers waking up to freezing temperatures today.
Ms Diamond said that more unsettled weather is due to hit Scotland on Wednesday and that snow could fall on higher ground, meaning it's unlikely to be a 'white Halloween' for most.
According to the Met Office website, temperatures in the capital should start to rise later in the week with highs of 13C expected on Saturday.
Ms Diamond said the lowest daily minimum temperature recorded in Scotland for October was -11.7C in Dalwhinnie in 1948, and the lowest daily maximum recorded was 0.4C in Inverness-shire.
The highest ever daily October temperature recorded in Scotland was 27.4C in Aberdeenshire in 1908.