Medan (Sumatra) weather in May
May in Medan: sweltering, soaked, with muggy air — not the time — 28 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#11 of 12 months in Medan · #1323 of 1413 destinations to visit in May · comfort 45/100 (tier F)
- Days
- 33°C
- Nights
- 24°C
- Wet days
- 28
- Sun
- 9 h
- Humidity
- 89%
- Daylight
- 12 h

Traveller notes on Medan in May
Notes from nearby Lake Toba (107 km away)
Medan doesn't have its own notes for May yet — these are about Lake Toba, close enough to share the season.
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.
Other months in Medan
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.
Add your own note from Medan's card on the map.
Medan climate normals — May
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Medan in May
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietschool holidays in 2 of the markets that fill it, one of its worst months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Medan's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Toughest weatherMedan's weather peaks January–March, best around February.
May coincides with Sinabung ash and alerts.
Best weatherFair weatherToughest weather
What's on in Medan in May
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Sinabung ash and alerts
1 Jan – 31 DecVolcanic activityClosuresThe volcano above Berastagi, two hours up the road, has spent years at raised alert with an exclusion zone around it. Ash falls close the Karo highland roads and occasionally the flight paths. Source ↗
- Season
Wet season
MonsoonRisk28 rainy days and about 315 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Medan — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Medan?
Medan in May — FAQ
- Is May a good time to visit Medan?
- May in Medan: sweltering, soaked, with muggy air — not the time — 28 rainy days. It ranks #11 of 12 months for Medan on SeasonMap's comfort score (45/100).
- What is the weather like in Medan in May?
- In May, Medan averages a daily high of 32.5°C and a low of 24.4°C, with about 314.6 mm of rain over roughly 27.5 rainy days.
- What is the air quality in Medan in May?
- Medan has a mean US Air Quality Index of about 95 in May.
Within 300 km: Penang's Wesak Day on 31 May.