United States Show cave
Meramec Caverns
14 °C inside, all year.
T.sujatha · CC BY-SA 3.0
The descent
The entrance, at 212 m.
The real relief above Meramec Caverns, measured on the Copernicus model every 30 m, and the cave going down at the same vertical scale.
The depth is the one published by those who explored it; the shape of the galleries is a sketch, not a survey. No depth has been published for this cave yet.
212m
Entrance altitude
from the 30 m relief model
14°C
Inside, all year
the yearly average outside, at the entrance
76m
Rock above
the highest point within 1.5 km
Inside and outside
14 °C inside, all year.
Deep inside, a cave keeps the average temperature of the year outside: about 14 °C here, in January and in August. In July the afternoon reaches 32 °C at the entrance, 19 °C warmer than inside: take a jacket. The best months to escape the heat are from June to September. The wettest months are in May: water rises fast underground, so never go in without a guide after heavy rain.
- 5°-5°Jan
- 7°-4°Feb
- 14°1°Mar
- 20°7°Apr
- 24°13°May
- 29°18°Jun
- 32°20°Jul
- 32°19°Aug
- 28°15°Sep
- 21°8°Oct
- 13°2°Nov
- 7°-3°Dec
Outside: afternoon and night averages for 1991–2020 (NASA POWER) brought to the altitude of the entrance. Inside: the yearly average, which deep parts of a cave keep. Near the entrance it follows the weather a little.
Cave system
Meramec Caverns is a show cave in United States. The entrance is at 212 m. It has an underground river, stalactites and stalagmites and several entrances and long galleries. It is open to visitors.
Getting there.
- Show cave: open to visitorsticket requiredOfficial site↗
- Sullivannearest town · 7.0 km in a straight line
- Parking 190 m awaynearest car park in OpenStreetMap, straight line
- St. Louis Lambert International Airport (STL)nearest airport with scheduled flights · 84 km in a straight lineCar hire at STL airport (St Louis)Discover Cars · sponsored link↗
Plan the visit
Guided tours, a bed nearby, a car.
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.
The water
The Meramec River runs highest from March to May.
The Meramec River carries about 29 m³/s on average here. It runs highest from March to May.
- 11 m³/sJan
- 19 m³/sFeb
- 55 m³/sMar
- 73 m³/sApr
- 69 m³/sMay
- 36 m³/sJun
- 17 m³/sJul
- 16 m³/sAug
- 13 m³/sSep
- 22 m³/sOct
- 27 m³/sNov
- 15 m³/sDec
From about 11 m³/s in the lowest month to 73 m³/s in the highest. Its basin above this point covers 3,972 km².
The Meramec River from source to mouth on Riveryas — coming soon
Estimate: long-term flow from the HydroATLAS model (WaterGAP, 1971–2000) shaped by the monthly rain, snow and temperature of the area (NASA POWER). Dams change it. Not a forecast.
From above.
The ground above the cave, with the relief shaded, the line of the section and what people have mapped around the entrance.
N
1.5 km
Sentinel-2 cloudless 2016 (EOX, CC BY 4.0), 6.0 × 6.0 km, north up. The line is the section above. Points © OpenStreetMap contributors.
Around the entrance.
- 6other cave entrances within 3 kmMeramec Caverns, Bat Cave, Panther Cave and 3 more
- 5springs within 2 kmLa Jolla Spring, Copper Hollow Spring and 3 more
- 8car parks within 2 km
- 16campsites within 8 kmBackpack Camp 8, Backpack Camp 3, Backpack Camp 5 and 13 more
- 17hotels and guesthouses within 8 kmMeramec Caverns Motel, Super 8, Comfort Inn and 14 more
- sinkholes within 3 km
- caving clubs and spots within 15 km
- viewpoints within 3 km
- marked hiking routes within 3 km
- climbing crags within 3 km
- named waterfalls within 4 km
- information boards and visitor centres within 3 km
- bus stops within 2 km
- restaurants and cafés within 3 km
Counted in OpenStreetMap, the map anyone can edit, around the entrance. A low number may just mean nobody has mapped it yet. © OpenStreetMap contributors (ODbL).
Towns nearby
- Sullivan7.0 km in a straight line
- Saint Clair15 km in a straight line
- Bourbon16 km in a straight line
- Union24 km in a straight line
In our other atlases
What else is around Meramec Caverns.
The river at the entrance, the waterfalls, the lakes, the mountains and volcanoes above, the canyons, beaches and islands nearby — from our other atlases.
Riveryas1 rivers at the entrance
Peakyas1 mountains within 10 kmFigures from the sister sites' databases (Wikidata, HydroATLAS, GeoNames, NOAA, OpenStreetMap). Links open when each site is online.
Month by month
The weather outside, at the entrance.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Afternoon | 5 | 7 | 14 | 20 | 24 | 29 | 32 | 32 | 28 | 21 | 13 | 7 |
| Afternoon | 5 | 7 | 14 | 20 | 24 | 29 | 32 | 32 | 28 | 21 | 13 | 7 |
| Night | -5 | -4 | 1 | 7 | 13 | 18 | 20 | 19 | 15 | 8 | 2 | -3 |
| Rain (mm) | 61 | 70 | 104 | 123 | 137 | 103 | 103 | 108 | 87 | 91 | 86 | 68 |
| Rainy days | 8 | 8 | 10 | 12 | 15 | 13 | 14 | 12 | 9 | 9 | 9 | 8 |
| Sun hours/day | 4.4 | 4.8 | 5.4 | 6.9 | 7.5 | 9.2 | 9.3 | 8.1 | 7.7 | 6.0 | 5.0 | 4.0 |
| Snow on the ground (cm) | 11 | 11 | 5 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 10 |
| Afternoon | Afternoon | Night | Rain (mm) | Sun hours/day | |
|---|---|---|---|---|---|
| Jan | 5 | 5 | -5 | 61 | 4.4 |
| Feb | 7 | 7 | -4 | 70 | 4.8 |
| Mar | 14 | 14 | 1 | 104 | 5.4 |
| Apr | 20 | 20 | 7 | 123 | 6.9 |
| May | 24 | 24 | 13 | 137 | 7.5 |
| Jun | 29 | 29 | 18 | 103 | 9.2 |
| Jul | 32 | 32 | 20 | 103 | 9.3 |
| Aug | 32 | 32 | 19 | 108 | 8.1 |
| Sep | 28 | 28 | 15 | 87 | 7.7 |
| Oct | 21 | 21 | 8 | 91 | 6.0 |
| Nov | 13 | 13 | 2 | 86 | 5.0 |
| Dec | 7 | 7 | -3 | 68 | 4.0 |
Averages 1991–2020 (NASA POWER) for a cell about 55 km wide, brought to the altitude of the entrance (212 m) with the standard lapse rate. Not a forecast.
Recent years
Wet years, dry years.
Rain of each month as a share of the 1991–2020 average. A dry year means a lower river and hotter rock; a wet one, more water in the gorge.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2020 | 255% | 111% | 130% | 97% | 102% | 88% | 157% | 89% | 53% | 161% | 133% | 72% |
| 2021 | 176% | 53% | 132% | 110% | 61% | 108% | 114% | 64% | 75% | 131% | 22% | 95% |
| 2022 | 72% | 158% | 131% | 111% | 134% | 35% | 78% | 132% | 60% | 86% | 77% | 77% |
| 2023 | 146% | 92% | 180% | 38% | 46% | 32% | 147% | 166% | 47% | 55% | 22% | 67% |
| 2024 | 178% | 13% | 83% | 118% | 135% | 85% | 194% | 49% | 78% | 32% | 264% | 108% |
| 2025 | 97% | 41% | 46% | 204% | 75% | 163% | 66% | 43% | 58% | 97% | 69% | 15% |
130% or more: wet month 70% or less: dry month
Caves nearby.
Meramec Caverns
United States
- —Depth
- —Galleries
- 212 mEntrance altitude
- 14 °CInside, all year
Bridal Cave
United States · 150 km
- —Depth
- —Galleries
- 265 mEntrance altitude
- 13 °CInside, all year
Current River Cavern
United States · 141 km
- —Depth
- —Galleries
- 164 mEntrance altitude
- 14 °CInside, all year
Mark Twain Cave
United States · 162 km
- —Depth
- —Galleries
- 174 mEntrance altitude
- 12 °CInside, all year
Where these figures come from
| Name, type, published depth and length, visitors | Wikidata (Q6817929) · CC0 |
|---|---|
| The relief above, the entrance altitude, the section and the 3D model | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| River flow and basin | HydroATLAS / RiverATLAS v1.0 (Linke et al. 2019) · CC BY 4.0 |
| Climate | NASA POWER, 1991–2020 |
| Entrances, springs, sinkholes, opening hours and what is around | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
| Rivers, waterfalls, lakes, mountains, canyons, beaches and islands nearby | Coastya, Lakeyas, Peakyas, Cascadyas, Islandyas, Riveryas |
Every figure is an average, an estimate or a count from a public dataset. Licences and methods: data sources.
The family
Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers, canyons, caves, dark skies, viewpoints, birdwatching or forests?
Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.
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