United States Waterfall UNESCO World Heritage
Union Falls
One of the waterfalls of United States.
In numbers.
0.46m³/s
Average flow
estimate
May–Jun
Best months
2,082m
Elevation
The water at Union Falls, month by month
It roars from April to May.
The fullest months: from April to May, with the snowmelt. The thinnest: from August to October and from December to February. Below −4 °C on average (from December to March): the falls can partly freeze.
- 0.1 m³/sJan
- 0.2 m³/sFeb
- 0.6 m³/sMar
- 1.5 m³/sApr
- 1.5 m³/sMay
- 0.9 m³/sJun
- 0.4 m³/sJul
- 0.2 m³/sAug
- 0.2 m³/sSep
- 0.2 m³/sOct
- 0.4 m³/sNov
- 0.3 m³/sDec
From about 0.13 m³/s in the lowest month to 1.5 m³/s in the highest. Best months to go, with plenty of water and pleasant days: from May to June.
Estimate: the timing comes from rain, snowmelt and evaporation (NASA POWER, 1991–2020); the amounts from the river model of HydroATLAS (WaterGAP, 1971–2000). Dams upstream can change the real flow.
Waterfall in Yellowstone National Park in Wyoming, United States
Union Falls is a waterfall in United States. It lies within Yellowstone National Park. It is part of a UNESCO World Heritage site.
Getting there.
- Yellowstone Airport (WYS)nearest airport with scheduled flights · 59 km in a straight lineCar hire at IDA airport (Idaho Falls)Discover Cars · Affiliate link↗
- From May to Junebest months to go (estimate)
Plan your visit
Stay, explore and get there
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.
Seen from the sky.
8 × 8 km of cloud-free satellite image, with what OpenStreetMap knows around the falls.
N
2 km
Sentinel-2 cloudless 2016 (EOX, CC BY 4.0), 8 × 8 km, north up. Points © OpenStreetMap contributors.
The line follows the river as mapped in OpenStreetMap; heights from the 30 m Copernicus model, which smooths narrow drops — the published height of the falls is the one above.
Around the falls the river drops 110 m in 2.1 km. Here the river runs about 44 m below the lower rim of its valley.
What is around.
- —viewpoints
- —waymarked walking routes
- —car parks
- —swimming spots
- —picnic sites
- —toilets
- —information boards and visitor centres
- —bus stops within 1 km
- —other named waterfalls within 4 km
- —caves
- 6campsites9C4S, Falls River Cutoff, Mountain Ash Creek and 3 more
- —hotels, B&Bs and huts within 6 km
- —restaurants and cafés within 3 km
Counted in OpenStreetMap, the map anyone can edit, up to 2 km around the falls (unless noted). A low number may just mean nobody has mapped it yet. © OpenStreetMap contributors (ODbL).
Weather
The weather, month by month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Afternoon °C | -4 | -3 | 1 | 5 | 12 | 19 | 25 | 24 | 19 | 9 | 1 | -4 |
| Night °C | -15 | -14 | -9 | -4 | 1 | 6 | 10 | 9 | 4 | -2 | -9 | -15 |
| Rain & snow (mm) | 83 | 73 | 73 | 75 | 72 | 61 | 30 | 36 | 50 | 65 | 76 | 90 |
| Wet days | 17 | 15 | 16 | 16 | 16 | 12 | 9 | 9 | 9 | 11 | 14 | 17 |
| Sun h/day | 4.1 | 5.6 | 6.5 | 8.0 | 8.1 | 10.0 | 12.0 | 10.3 | 8.4 | 5.5 | 3.9 | 3.3 |
| Snow on the ground (cm) | 66 | 81 | 75 | 37 | 11 | 2 | 0 | 0 | 3 | 11 | 19 | 39 |
Long-term averages 1991–2020 (NASA POWER) for a cell about 55 km wide, with temperatures carried to the height of the falls (2,082 m) at −6.5 °C per 1,000 m. Not a forecast.
Photos
Through visitors' eyes.
Recent years
Wet years and dry years
Rain of each month as a share of the 1991–2020 average. A wet season above 100 % usually means a fuller waterfall.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2020 | 121% | 91% | 120% | 92% | 101% | 171% | 94% | 31% | 62% | 89% | 109% | 44% |
| 2021 | 65% | 96% | 41% | 34% | 116% | 11% | 99% | 201% | 51% | 100% | 60% | 113% |
| 2022 | 49% | 16% | 39% | 95% | 119% | 111% | 34% | 176% | 99% | 63% | 110% | 92% |
| 2023 | 63% | 93% | 136% | 68% | 73% | 161% | 77% | 247% | 125% | 125% | 53% | 65% |
| 2024 | 78% | 132% | 147% | 61% | 91% | 50% | 61% | 115% | 110% | 35% | 59% | 87% |
| 2025 | 50% | 165% | 99% | 63% | 82% | 37% | 69% | 117% | 78% | 138% | 39% | 179% |
130% wetter than usual 70% drier than usual
Compare with the waterfalls nearby.
Union Falls
United States
- —Height
- 0.46 m³/sAverage flow
- May–JunBest months
About these numbers
| Names, height, width, river | Wikidata (Q38037) · CC0 |
|---|---|
| River flow and catchment | HydroATLAS / RiverATLAS v1.0 (Linke et al. 2019) · CC BY 4.0 |
| Climate | NASA POWER, 1991–2020 |
| Relief, river profile, 3D model | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| Paths, viewpoints, parking | © 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.
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