Antigua and Barbuda lie in the eastern arc of the Leeward Islands of the Lesser Antilles, separating the Atlantic Ocean from the Caribbean Sea. Antigua is southeast of Puerto Rico; Barbuda lies due north of Antigua, and the uninhabited island of Redonda is southwest of Antigua.
The largest island of Antigua, is 21 km (about a dozen miles) across and 281 km<sup>2</sup> (about a hundred square miles) in area. Barbuda covers while Redonda encompasses . The capital of Antigua and Barbuda is St. John's, located at St. John's Harbour on the northwest coast of Antigua. The principal city of Barbuda is Codrington, located on Codrington Lagoon.
In Antigua and Barbuda forest cover is around 18% of the total land area, equivalent to 8,120 hectares (ha) of forest in 2020, down from 10,110 hectares (ha) in 1990.
Antigua and Barbuda both are generally low-lying islands whose terrain has been influenced more by limestone formations than volcanic activity. The highest point on Antigua is Boggy Peak, the remnant of a volcanic crater rising 402 meters (1,319 ft). This mountain is located amid a bulge of hills of volcanic origin in the southwestern part of the island. Lake Estate is the third tallest recorded point on Antigua.
The limestone formations in the northeast and northwest are separated from the southwestern volcanic area by a central plain of clay formations. The map of northeastern Antigua features several small and tiny islands, some inhabited. Barbuda's highest elevation is , part of the highland plateau east of Codrington. The shorelines of both islands are greatly indented with beaches, lagoons, and natural harbors. The islands are rimmed by reefs and shoals. There are few streams as rainfall is slight. Both islands lack adequate amounts of fresh groundwater. Tiny Redonda rises to and has very little level ground, while Barbuda is very flat with few if any hills.
Due to the spread out islands it has an Exclusive Economic Zone of .
The islands' climate is moderated by fairly constant northeast tradewinds, with velocities ranging between . There is little precipitation because of the islands' low elevations. The pleasant climate fosters tourism.
Rainfall averages per year, with the amount varying widely from season to season. In general the wettest period is between September and November. The islands generally experience low humidity and recurrent droughts.
Hurricanes strike on an average of once a year between July and October. Temperatures average , with a range from in the winter to in the summer and autumn. On 12 August 1995, a temperature of was recorded at St. John's. This is the highest temperature to have ever been recorded in Antigua and Barbuda. The coolest period is between December and February.