Karaikal features a tropical savanna climate bordering on a tropical wet and dry climate (Köppen climate classification *Aw*). The weather is generally hot and humid throughout the year.
Summer peaks between April and June, with average high temperatures often reaching 35°C to 38°C (95°F to 100°F). The city receives the bulk of its rainfall not from the Southwest Monsoon, but from the Northeast Monsoon between October and December. During this period, heavy downpours and occasional cyclonic storms originating in the Bay of Bengal are common. Average annual rainfall is approximately 1,200 mm to 1,300 mm. The most comfortable time to visit is during the brief, milder winter season from December to February, when temperatures range from 22°C to 30°C (72°F to 86°F).