San Guillermo, in Cagayan Valley, Philippines, is home to roughly 3,900 people in the Asia/Manila time zone at 16.7°N latitude.
Recent weather here gives a sense of typical conditions: in 2025, San Guillermo recorded a mean annual temperature of 78°F, ranging from 65°F lows in February to 97°F highs in June, with about 135 inches of precipitation across the year.
View historical weather for San Guillermo · More cities in Cagayan Valley