Winters in Penafiel are cool and mild, with temperatures ranging from around freezing to the mid-teens Celsius. Daytime temperatures gradually warm up as spring approaches, reaching highs of over 20 degrees by April. Summer is warm to hot, with frequent temperatures above 30 degrees, while autumn sees a return to more moderate conditions, with temperatures dropping back down into double figures by October. The coldest months are January and December, which average around 7-11 degrees Celsius, while the warmest month is usually July, averaging just over 19 degrees. Spring and autumn tend to be mild, with gentle temperature fluctuations.