Ponta Delgada has a subtropical Mediterranean climate with warm to hot summers and very mild winters. It has also a certain proximity to a humid subtropical climate and an average low around 15 °C (59 °F). Temperatures above 30 °C (86 °F), or below 4 °C (39 °F) have never been registered. Humidity is constantly high, staying around 80% year-round, which may influence its perceived temperature by a few degrees, especially in summer.
The Gulf Stream also contributes to an unstable weather that varies greatly during autumn and spring, making weather forecasting on a daily basis difficult. Winters are generally milder and summers are generally humid when compared to those of continental Portugal. Its location is one of the limits for pressure measurement to verify the North Atlantic Oscillation (NAO).