The climate of the area is characterised by two pronounced seasons – dry from November to April and wet for the rest of the year.
Temperature and Humidity
Mean annual temperature is 27.6ºC and is relatively cool due to the site’s elevation and favourable airshed condition. The warmest month is May with an average of 30.0ºC while the coolest month is January with an average temperature of 25.0ºC.
Average relative humidity, the measure of the moisture content of the atmosphere is 80% in Santa Rosa. This makes the city fairly cooler than the Metropolitan Manila area where average relative humidity exceeds 81.0%.
Wind Speed and Direction
Northeasterly winds prevail during the months of October through February. Winds come from the southeast during March and April. Southerly winds prevail during May while from June through September southwesterly winds prevail. The average speed of winds is 5 kilometres per hour.
Rainfall and Rainfall Intensity
Annual average rainfall is notably 1,950 millimetres. The maximum rainfall occurs in October while minimum rainfall is gauged at 2 millimetres. Though the municipality is located in a region subject to typhoons, Santa Rosa is hardly affected due to protection from the outlying mountain areas.