Seasonal temperature variation is less extreme than most of the United Kingdom because of the adjacent sea temperatures. The summer months of July and August are the warmest, with mean daily maxima of approximately 21 °C (70 °F). In winter mean minimum temperatures of 1 °C (34 °F) or 2 °C (36 °F) are common.[24] In summer the Azores high pressure affects the south-west of England, although convective cloud sometimes forms inland and reduces the number of hours of sunshine.