Devonport has an warm-summer mediterranean climate (Köppen climate classification Csb), bordering on an oceanic climate (Köppen climate classification Cfb). It has mild to warm summers, cool and moist winters. It has high humidity (about 70%) all year round. Most days from January to March are pleasantly warm, averaging with frequent sunshine. The warmest and driest days can reach up to . Unlike the south and east coasts of Tasmania, humid northerly winds prevent heatwaves and temperatures rarely go above . Winters are cool and cloudy with frequent light rain; July and August are the wettest months of the year. In winter, because of the constant cloud cover and effect of the sea, winter temperatures rarely drop below or rise above . September to December has mild and windy weather with frequent showers, and occasional warm, sunny breaks. 