Ski areas could also become crowded, as snow conditions are still excellent for the time of year, Austrian broadcaster ORF reports.
ORF has predicted temperatures as high as 25 degrees in the Inntal, Walgau and Salzach Valley. Around 23 or 24 degrees in Vienna, Graz and Klagenfurt.
The warmest days will be Wednesday and Maundy Thursday, which also coincides with the start of a strict lockdown in the east of Austria.
On Good Friday the weather will become cooler and rain is forecast, with possible lightning and thunder.
However, in parts of Austria, including Tyrol, Carinthia and Styria, there will be temperatures above 20 degrees and sunshine.
According to ORF, normally the first summer day in Austria does not arrive until mid-April. Last year it was on April 10th in Hermagor in Carinthia, and on April 20th in Innsbruck in 2019.
The warm weather means that blossom can already be seen all over Austria. Forsythia is already blooming in large parts of Austria, the apple trees are coming into bud, and people allergic to pollen will soon notice the birch blossom blooming.
In a few days, the famous apricot trees will begin flowering in the Wachau, transforming the wine growing area into a sea of pink and white flowers.