Donostia's winters are mild, with temperatures rarely dropping below 0°C and averaging around 7-12°C in January and February. As spring approaches, temperatures gradually rise, reaching averages of 11-15°C by May. Summers are warm to hot, with July and August often seeing highs above 35°C and averages around 20°C. Autumn brings a return to milder temperatures, with September's averages mirroring those of winter, before cooling off in November and December.