Thanks to its Caribbean location, George Town enjoys a tropical marine climate with only mild temperature fluctuations over the course of the year. Summers (May to October) are warm and humid with frequent thunderstorms, while winters (November to April are cool and farily dry. Trade winds and the Caribbean Sea ensure that temperatures remain close to 80°F (27°C) year-round. The thermometer rarely hits 90°F (32°C) even during the summer, and the coldest the islands get during the winter is about 70°F (21°C). The town gets about 50 inches (130cm) of rain a year, much of which occurs in the shoulder season months of May and October. During the peak tourist summer season, you can expect perhaps 5 inches (13cm) of rain per month. This drops to about 2 inches (5cm) during the winter.

Also due to its Caribbean location, George Town is at risk of severe storm damage every year during hurricane season, which runs from June to October, inclusive. In September 2004, the Category 5 Hurricane Ivan swept through Grand Cayman, damaging 70% of the buildings on the island. Restrictions on travel to Cayman had to be put in place for two months. In the event of another hurricane, you will have to evacuate or seek shelter quickly, so keep an eye on the weather conditions while in George Town.