Nomadtales ( talk · contribs ) · CC BY-SA 2.1 au · Wikimedia Commons
Highest mountain in Papua New Guinea
Mount Wilhelm is a mountain in the Bismarck Range (Papua New Guinea). Its summit stands 4,509 m above sea level. It is the highest point of PG. Its prominence — how far it rises above the highest saddle linking it to a taller summit — is 2,969 m, and the nearest higher ground is 539 km away.
From the lowest point within 5 km (2,768 m), it rises 1,741 m. The steepest side is the north-east face: 28° on average over the first kilometre. In places the ground near the top reaches 47° — terrain for climbers, not walkers.
Scores
Two scores out of 10, built only from open data — every part is shown. They describe what the mountain offers, not how safe it is.
Hiking & mountaineering
5.0/10
Difficulty to the top
Alpine climb
Estimated from the slope: OpenStreetMap has no graded paths near the top.
Indicative only — never a safety assessment. Conditions change: ask local guides and check the forecast.
Ski score
—
No ski runs within 12 km in OpenStreetMap.
Ski (where OpenStreetMap has skiing within 12 km): up to 4 points for the length of downhill runs (300 km or more = 4), 1.5 for the number of lifts (40+), 1.5 for the vertical between lift stations (1,500 m) and 3 for the snow season — a month counts when the estimated mean temperature at the height of the ski area is −1 °C or lower and snow falls or lies there (NASA POWER, 2001–2020). Hiking & mountaineering: up to 2.5 for waymarked routes and paths, 1.5 for huts, 2 for the ascent from the valley (2,000 m), 1.5 for prominence (3,000 m), 1.5 for the season (months with summit afternoons above −5 °C) and 1 for via ferratas, climbing and glaciers. OpenStreetMap is built by volunteers: where few things are mapped, a score can be lower than reality.
Plan your visit
Some links above are affiliate links: if you book through them we may earn a commission, at no extra cost to you. It never changes what the data on this page says.
Snow
At the summit, occasional snow all year. Month by month below, at different heights on the way up.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Summit4,509 moccasional snow all year | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time | Snow some of the time |
Halfway up3,638 mno snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow |
Foot of the mountain2,768 mno snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow |
Estimate for a normal year: average temperature and precipitation from NASA POWER, carried to each height, in a simple model of snow building up and melting. In a given year snow can come earlier or stay longer. It does not replace the local snow and avalanche bulletin.
Summit weather
Not a forecast: long-term averages (1991–2020), carried up to the summit. The orange line is where an average afternoon reaches 0 °C; above the dashed blue line it freezes even at dawn.
On an average December afternoon the summit reaches about 4 °C; on August nights it falls to about -4 °C. Afternoons at the top are above freezing in every month of the average year. In December the 0 °C line climbs to about 5,100 m, above the summit: the top thaws on an average afternoon. Across the region, August is the driest month (77 mm) and March the wettest (225 mm).
| Month | Summit high °C | Summit low °C | 0 °C line (m) | Rain & snow (mm) | Wet days | Sun h/day |
|---|---|---|---|---|---|---|
| January | 4 | -3 | 5,060 | 207 | 20 | 5.1 |
| February | 4 | -3 | 5,050 | 182 | 20 | 5.0 |
| March | 3 | -3 | 5,020 | 225 | 22 | 4.9 |
| April | 3 | -3 | 4,990 | 184 | 20 | 5.4 |
| May | 3 | -3 | 4,970 | 149 | 17 | 6.1 |
| June | 3 | -3 | 4,940 | 108 | 16 | 6.3 |
| July | 3 | -4 | 4,930 | 80 | 13 | 6.3 |
| August | 3 | -4 | 5,020 | 77 | 12 | 6.6 |
| September | 4 | -4 | 5,060 | 109 | 13 | 6.4 |
| October | 4 | -4 | 5,080 | 116 | 15 | 6.3 |
| November | 4 | -3 | 5,080 | 162 | 18 | 5.7 |
| December | 4 | -3 | 5,100 | 167 | 20 | 5.7 |
Estimate: the NASA POWER climate of a ~55 km cell (average height 1,834 m), adjusted to the summit by −6.5 °C per 1,000 m. Rain, wet days and sunshine are those of the region. Mountain weather changes fast — always check a local forecast. ★ = mildest months at the top.
Relief
Two cuts through the summit, 16 km long, from the 30 m Copernicus elevation model. Heights drawn 2× taller than lengths, so the shape can be seen.
Average slope of the first kilometre from the summit. The orange petal is the steepest side.
Around the mountain
Counted around the summit in OpenStreetMap, the map anyone can edit. The satellite plate shows 14 × 14 km.
N
5 km
Sentinel-2 cloudless 2016 (EOX, CC BY 4.0), 14 × 14 km, north up. Points © OpenStreetMap contributors.
A-Frame
Khu Poke, Seeku
Camp Jehovah Jireh, Betty's Lodge, Mondia Bris Guesthouse, Kegesuglo Guest House
OpenStreetMap is built by volunteers: a low number may just mean nobody has mapped it yet. Places © OpenStreetMap contributors (ODbL).
Recent years
Afternoon high at the summit (estimate). The first row is the reference, the 1991–2020 average in °C; the years show only the difference.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1991–2020 average | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 |
| 2020 | +0.5 | +0.6 | +0.3 | +0.5 | +0.8 | +0.4 | +0.5 | +0.3 | +0.6 | −0.1 | −0.2 | −0.3 |
| 2021 | +0.7 | −0.2 | −0.3 | −0.5 | +0.4 | ±0.0 | +0.4 | ±0.0 | +0.3 | +0.1 | +0.5 | −0.1 |
| 2022 | −0.2 | ±0.0 | +0.6 | ±0.0 | +0.4 | +0.3 | +1.0 | +0.5 | +1.1 | +1.5 | +0.8 | −0.3 |
| 2023 | +0.2 | +0.1 | +0.7 | +1.0 | +0.4 | +0.2 | +0.8 | +1.1 | +1.6 | +0.2 | +0.8 | +0.8 |
| 2024 | +1.1 | +1.3 | +1.2 | +1.0 | +1.1 | +1.5 | +1.2 | +1.2 | +0.5 | +0.9 | +1.4 | +0.9 |
| 2025 | +2.6 | +0.9 | +1.3 | +0.3 | +0.7 | +0.8 | +0.9 | +1.1 | +1.8 | +2.9 | +0.6 | +0.5 |
+1 warmer than usual −1 cooler than usual
| Names, elevation, prominence | Wikidata (Q277441) · CC0 |
|---|---|
| Relief, 3D view, profiles | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| Climate | NASA POWER, 1991–2020 · CC BY 4.0 |
| Around the mountain | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
Every figure is an average, an estimate or a count from a public dataset. Licences and methods: data sources.
The family
Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.
beaches
Find your beach: sea temperature, sun and swimming month by month.Visit 
lakes
Every lake on Earth: water temperature, ice, depth and the shore.Coming soonVisit 
mountains
Every summit in 3D: summit weather, the 0 °C line, huts and trails.You are here
waterfalls
Every waterfall: height, flow month by month and when it roars.Coming soonVisit 
islands
Every island from the sea up: size, sea temperature, ferries and 3D.Coming soonVisit 
rivers
Every river from source to sea: the journey, the flow and the basin in numbers.Coming soonVisit 
