Do you need thermal gloves and a winter hat when hiking Rinjani in August?

Yes, take thermal gloves and a warm hat for Rinjani even in August, because the dry season does not warm the summit. The predawn climb is estimated at roughly 0 to 4 degrees Celsius, conditions approach freezing before sunrise at 3,726 meters, and wind on the exposed ridge makes the same air feel colder still. August sunshine in the Sembalun valley is a different world from the summit ridge far above it.

The standard local packing list agrees: it includes thermal top and bottom, fleece, insulated jacket, outer shell, warm hat and gloves. Hands get the worst of the summit wait, because you stand still on volcanic rock in wind near freezing, and cold hands also mean clumsy hands on a descent you want controlled. Gloves and a beanie cost almost no pack volume compared with a spoiled summit hour, which is why guides put them on the list for every month of the open season, not just the shoulders.

August misleads visitors because Lombok sells beach weather. The villages at the foot of the mountain sit at roughly 1,150 meters and can feel pleasantly warm at midday, and guests pack accordingly, then meet an evening at the rim camp around 2,639 meters that already wants a jacket. The summit night compounds that gap with another thousand meters of altitude, darkness and wind, and the difference between a good summit experience and a miserable one is very often a hat and gloves.

Practical notes: choose gloves you can grip trekking poles with, keep them in your personal daypack rather than any communal load, and check at the pre-trek briefing that everyone in your group has them, because a summit turn-around for one underdressed guest is a real outcome. A working headtorch with spare batteries completes the small kit that the 02:00 start genuinely needs. If your gloves are thin liners, bring a shell layer for your hands as well, since wind, not just temperature, is what strips heat fastest on the ridge.