New Plymouth has an oceanic climate that could be described as a moist, temperate climate.
The average summer afternoon temperature is 21–22 °C (70–72 °F); average summer night-time temperature is 12–13 °C (54–55 °F).
The city experiences mild winters, where the average afternoon temperature is 13–14 °C (55–57 °F) and night-time temperature is 5–6 °C (41–43 °F).
The average annual rainfall is 1,432 mm (56.4 in). On 15 August 2011 it snowed in New Plymouth, a rare event which has been described as a once in a generation occurrence.
Schools were given the day off and workplaces dismissed due to the significance of the event.