The Dominican Republic has a tropical climate, but the country is varied enough that "best season" depends on what you want. The Caribbean south coast is drier and hotter than the Atlantic north; the Cordillera Central interior is markedly cooler.
High season (December–April) is the obvious time to come. Dry, sunny, low humidity, and outside the hurricane window. Christmas, New Year, and Easter Week (Semana Santa) are extremely busy and expensive — book ahead.
Shoulder (April–June) is excellent value: temperatures still pleasant, the spring rains modest, and prices much lower. Whale watching off the Samaná Peninsula runs January through mid-March, when humpbacks calve in the bay.
Wet season (May–November) brings afternoon showers — usually short — and rising humidity. The interior mountains and Jarabacoa stay cool and green.
Hurricane season (June–November) peaks August through October. Direct hits are rare but significant storms do happen; check forecasts before booking and consider travel insurance with hurricane provisions.
Carnival runs through February, with the biggest celebrations in Santo Domingo, La Vega, and Santiago. Merengue Festival takes over Santo Domingo's Malecón in late July.