The best time to visit Yemen — in terms of climate — is October to March, when temperatures are moderate across most of the country and rainfall is low on the coasts. The highlands around Sana'a are pleasant year-round but can be cold at night in winter, as the city sits at 2,200 metres. Summer (June to September) brings monsoon rains to parts of the south and west, which turn the Haraz mountains green and dramatic but can make roads difficult.
The Tihama coastal plain along the Red Sea is hot and humid almost year-round and brutal in summer. The Hadramawt and eastern desert regions are dry and extremely hot from May to September, with temperatures regularly above 40°C.
Socotra experiences its own climate. The island is largely inaccessible from June to September due to the Indian Ocean monsoon, which brings powerful winds and heavy seas. The best months are October through April.
The civil war has suspended normal considerations of seasonal tourism entirely. Travel restrictions and security conditions are driven by the conflict, not the calendar.