Het weer in Medan (Sumatra) in mei

Lake Toba-forum threads on a May visit describe this as genuinely a good stretch, posters naming May through August as the broader recommended window with cooler evenings than the hottest months. Regulars call three to four days at Tuk Tuk on Samosir Island genuinely standard, several posters naming Carolina, Bagus Bay and Samosir Cottages as reliable places to stay. Posters call combining a Toba trip with Berastagi genuinely a popular route, several regulars naming the Sibayak and Sinabung volcanoes alongside real hot springs as reasons to add the stop. Regulars call Sipiso-piso waterfall a real worthwhile detour en route, several threads naming this easy to combine with the wider itinerary. Posters recommend building in real time for both the lake and Berastagi rather than rushing, several regulars calling this standard given how much there is to see. The record: 26.4C days, 22.1C nights, an extraordinarily high 250.3mm across over 28 days and 85 percent humidity.

Forum posters describe the broader Indonesia dry season, roughly June through August, as generally recommended for travel, though posters note rain remains a near-constant presence across the archipelago's calendar rather than disappearing entirely - a full day of nonstop downpour is unusual, with more typical patterns being a few hours of passing rain followed by sunshine again. It is worth noting that for Medan specifically, the full 12-month climate record shows August is not actually among its driest months - January and February run noticeably drier here, with rain staying elevated from April through December. Posters consistently recommend packing rain gear regardless of the season given how unpredictable North Sumatra's weather can run. Posters generally rate August as warm and genuinely rain-prone for Medan, the wider Indonesian dry-season framing not holding up well for this particular city.

Forum posters describe February as still squarely inside the region's rainy season, with daily rain a real possibility running well into the following months - though posters note February is generally a bit drier than January, even as climate patterns have grown less predictable in recent years. For Medan and North Sumatra specifically, posters describe conditions as genuinely unpredictable day to day, recommending flexibility built into any itinerary through Lake Toba and Berastagi rather than counting on a dry stretch. Posters contrast this with parts of eastern Indonesia like Lombok and Komodo, which tend to run drier at the same time of year for anyone able to adjust their route.