First frost reported in Lower Austria and Switzerland

Sub-zero temperatures have been recorded in parts of Lower Austria, specifically in the Waldviertel region, where temperatures reached -3.9 degrees Celsius in Zwettl and -1.4 degrees Celsius in Litschau. This onset of frost necessitates precautions for gardeners, such as protecting sensitive Mediterranean plants like oleander and citrus trees, covering hardy perennials with fleece, and insulating container roots.

In Switzerland, meteorological observations highlight the discrepancy between official air temperatures and ground-level frost. While standard air temperature is measured approximately two meters above the ground, ground frost occurs in the thin layer of air just above the soil. In clear, windless conditions, the surface can drop below freezing even if official readings show positive temperatures, posing a significant risk to young plant tissues, blossoms, and new shoots.