The mercury hit a sweltering 31.3C in Aviemore in the Highlands, making it the warmest day of the year so far and the hottest June day since 1995.
Aboyne, in Aberdeenshire, was almost as hot, with a high of 30.1C.
Yesterday’s high temperature broke the previous 2018 record for Scotland of 27.5C, set at Achnagart in the Highlands in May.
The western side of the country was generally the hottest, with temperatures of 28C in Glasgow and Tyndrum, Perthshire, and 27C at Threave, in Dumfries and Galloway, according to Met Office figures.
Temperatures were slightly cooler in the east, reaching 22.8C in Aberdeen and 19C in Edinburgh.
At Luss beach, Loch Lomond, the sizzling temperature saw beachgoers sunbathing and taking a dip in its waters.
Karalee Conboy, 35, who travelled from Glasgow, said: “I often come here with my children when the weather is good. It’s good – as long as they are happy, I am happy. We’ll have a picnic and build some sandcastles.
“We were going to go abroad but then I thought why go away when we’ve got this on our own doorstep, it’s a lovely place. Scotland is definitely underestimated but it really is one of the nicest places.”
Iain Elliot, 47, from Bristol, who towed his boat north last Saturday to enjoy the Scottish sun, said: “It’s something special and we’ve been lucky with the weather.
“I come up every year and it’s a special place. I love the scenery so much and you are never disappointed.”
Restaurant worker Marta Garcia, 26, from Spain, said: “I have lived here for three years now and love it. The weather today is so good and I’m really just sad that I have to go to work at 5pm.
“This is the first time I’ve been out here in ages when the sun is out and I just want to stay.”
It was also the hottest day of the year so far across the UK, with thermometers peaking at 31.9C in Porthmadog in Wales.
But with the heatwave expected to continue today, meteorologists said temperatures in Scotland could even go on to break the June record of 32.2C, measured in 1893 at Ochtertyre in Perthshire.
Met Office forecaster Mark Wilson said: “We’re keeping a close eye on temperatures, as highs of around 31C or 32C are expected in some places on Thursday. At this point it looks unlikely to beat 32.2C, but it’s not out of the question.”
But not everyone has been basking in tropical heat.
Shetland, though warmer than it has been for the previous couple of days, saw a much chillier 11C in the coolest parts.
However, Scots are being asked not to waste water during the dry weather due to concerns that reservoirs are running low.
Scottish Water has issued warnings over supplies in Elgin, Forres, Kinloss and Stornoway, asking customers to “use water wisely”.
The firm said the heatwave coupled with increased demand means “efficiency measures” are needed, such as turning taps off while brushing teeth, taking shorter showers, not over-filling kettles and using watering cans instead of hosepipes outdoors.
People also warned people to take care at quarries. Police issued a warning on Twitter, saying: “Some quarry lakes may look inviting on a hot summer’s day like today, but there are a number of hidden dangers: Deep water, submerged abandoned machinery and car wrecks, underwater recesses, hidden currents, dead animals, pollution.
“More dangers of quarry swimming are sheer faces, falling rocks, quick sand, and believe it or not hypothermia.”