In a Saturday statement, the DWD said showers, some very heavy, and storms should be expected across the southern part of the country into the night, while the entire country would be windy and cooler.
Temperatures on Saturday will hit highs of up to 22 degrees Celsius, although it will be cooler on the coasts. And after a stormy start to Saturday night, skies will clear with just scattered cloud cover, which will result in cooler temperatures of around 11 degrees on the Rhine and Main rivers and down to around 2 degrees in the north-east.
Some unlucky areas there could even get a light ground frost, the DWD warned.
Sunday will be sunny in many places, with showers expected only in the south, while the Alpine areas and Mittelgebirge region of southern Germany will have storms.
Farmers will welcome any rainfall, as reports from a number of regions suggest a threatening drought which could result in crop losses. Some are already using watering machines on their fields. The hopes are that May will be wet, in order to save the harvest.
Temperatures will only reach around 14 degrees in the northeast and 21 in the southwest, with reasonable winds.
Sunday night will again be chilly, with frost to be expected in some areas of the northeast.
Monday is expected to be largely clear with some cloudy areas, and mostly dry, with just a few showers near the Alps. Top temperatures of 11 degrees in the north and 20 in the south repeat the pattern of a country divided by a cool front.