Karlsruhe has a mild continental climate with warm summers and cold winters. The city is at its best from May through September, when the outdoor cafes fill, the Schlosspark and Municipal Park are in full leaf, and the days are long. The Karlsruhe Festival (Schlosslichtspiele) in August projects light installations onto the palace facade — a popular summer event drawing visitors from across the region.
Spring (April–May) is excellent: blossom in the Schlosspark, warm enough to sit outside, and fewer tourists than summer. The Christmas market in November–December is well-regarded and draws visitors from across southwest Germany and neighbouring Alsace. Winter is cold but rarely extreme; snowfall is possible in December and January. The university keeps the city animated year-round, so even in the quieter months Karlsruhe functions well.