High air pressure and a warm föhn wind from the west will see temperatures north of the Alps from 23C and up to 30C.
The UBIMET weather service says it will be the warmest day of the year so far. However, temperatures are set to fall next week with rainshowers returning.
The areas likely to have the highest temperatures are Lower Tyrol, Flachgau, and the region from Salzkammergut to Mostviertel, according to UBIMET meteorologist Konstantin Brandes. "By the late afternoon and evening, there are likely to be the first rain showers and thunderstorms in Vorarlberg and North Tyrol which signal the approaching weather change.”
In the first round of the presidential election last month, Hofer comfortably beat his rival by 35 percent to 21 percent. It's thought that Hofer will have the full support of Freedom Party voters, as well as a large majority of disaffected voters and ‘protest' votes who are angry about the migrant crisis and rising unemployment.
Van der Bellen must hope that he has won over those who would normally vote SPÖ and ÖVP - as well as those who voted for independent candidate Irmgard Griss in the first round.
A recent TV debate between Hofer and van der Bellen was described by Austrian media as “embarrassing” and an “undignified farce” as the two traded insults.
While Austria's president is largely a ceremonial role, Hofer has sparked controversy with his claim that he would, as president, use his power to dismiss the government under certain circumstances.
For the first time since 1945, the president will not come from one of the two main parties, the SPÖ or the ÖVP.