Merthyr Tudful experiences a moderate climate with temperatures gradually warming up as the seasons progress. In winter, from December to February, temperatures are generally mild, ranging from just below freezing to around 14°C, with an average temperature of around 7-10°C. As spring approaches in March and April, temperatures rise steadily, reaching averages of 9-13°C. Summer months of June to August bring warmer temperatures, often above 20°C, with July being the warmest month averaging 20°C. Autumn sees a gentle decline in temperatures, returning to more moderate ranges from September to November, before the cycle repeats itself in winter.