Temperatures will reach up to 31 degrees Celsius by afternoon, when a cold front will roll in from the west across the country, the German Weather Service (DWD) reported from its headquarters in Offenbach. The front will squelch the late-summer heat with showers and thunderstorms nationwide.
The second half of the week will be mixed and windy.
On Wednesday, storms will reach eastern and southern Germany, though cloud cover in the west is expected to clear up slightly. The Alps will see isolated storms. Temperatures will range between a cooler 21 and 25 degrees Celsius.
Thursday will begin mildly, but cloud cover and storms will spread from west to east as coastal areas and high altitudes batten down for gale force winds. Temperatures will be between 20 and 25 degrees Celsius.
September's stormy weather comes after what DWD said was an unusually sunny and warm August. The average temperature of 18.7 degrees was 2.2 degrees higher than the average in the last four years. Meanwhile sunshine surpassed the record of 197 hours by almost one-third to reach 246. Berlin was the sunniest city with 274 hours of sunshine in August.