About Grand Roy, Saint John Parish's Climate & Weather History

Grand Roy, in Saint John Parish, GD, is home to roughly 2,400 people in the America/Grenada time zone at 12.1°N latitude.

In 2025, Grand Roy recorded an average annual temperature of 81°F. The hottest temperatures reached 90°F in September; the coolest were 72°F in February. Total precipitation for the year was 45 inches, with the wettest month being October.