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River

Lerma River

750 km from source to mouth · Mexico.

MexicoMexicoFlows into Lake Chapala3rd longest in Mexico

Follow the riverMonth by month

SourceMouthSalamancaAcámbaro
The river and every tributary in its basin, drawn from RiverATLAS (CC BY 4.0).

In numbers

Length

750km

Average flow

340m³/s

Basin

38,500km²

Drop

1,049m

from 2,571 m to 1,522 m

Country

1

The journey

From source to mouth

750 km of river and 23 stops on the way: 22 towns and cities on its banks, dams, bridges and the tributaries that feed it.

2,571 m1,522 m
Almoloya del Río Municipalityat 2,571 m0 km
Atlacomulco de Fabela22,774 people128 km
Temascalcingo12,698 people160 km
Acámbaro108,697 people303 km
Salamanca160,682 people424 km
La Piedad de Cabadas83,323 people599 km
La Barca35,219 people688 km
Lake Chapalaat 1,522 m750 km
0200400600750 km
  1. 0 kmAlmoloya del Río Municipalityat 2,571 m
  2. 7 kmAlmoloya del Río9,507 people
  3. 8 kmSanta Cruz Atizapán8,062 people
  4. 12 kmSan Pedro Tlaltizapan11,472 people
  5. 19 kmSan Pedro Chochula8,798 people
  6. 19 kmSan Pedro Cholula8,941 people
  7. 21 kmSan Pedro Tultepec13,634 people
  8. 22 kmSan Mateo Atenco67,890 people
  9. 25 kmLerma de Villada22,713 people
  10. 29 kmEl Cerrillo Vista Hermosa8,699 people
  11. 43 kmVilla Cuauhtémoc11,241 people
  12. 91 kmSanto Domingo de Guzmán8,008 people
  13. 98 kmSan Pedro Los Baños11,886 people
  14. 128 kmAtlacomulco de Fabela22,774 people
  15. 160 kmTemascalcingo12,698 people
  16. 303 kmAcámbaro108,697 people
  17. 340 kmSalvatierra37,203 people
  18. 377 kmJaral del Progreso20,457 people
  19. 424 kmSalamanca160,682 people
  20. 599 kmLa Piedad de Cabadas83,323 people
  21. 599 kmSanta Ana Pacueco10,052 people
  22. 649 kmYurécuaro23,843 people
  23. 688 kmLa Barca35,219 people
  24. 724 kmLake Chapala1,052 km²
  25. 750 kmLake Chapalaat 1,522 m

Water level along the river (RiverATLAS; the height is exaggerated). Towns: GeoNames and Wikidata; bridges, dams and tributaries: Wikidata.

River in Mexico

At the mouth it carries 345 m³/s on average: an Olympic pool every 7.2 seconds. It drops from 2,571 m to 1,522 m, 1.4 m per kilometre on average. Its basin covers 38,500 km², about the size of GW. 10.8 million people live in it. Highest water: from August to September; lowest: from January to April. It is heavily dammed: reservoirs can hold 88% of a year's flow.

Read more on Wikipedia

Where to start

Lerma River, month by month

Highest water: from August to September

Lowest water: from January to April. Best months to visit: from January to April and November.

26
14°15 mmJan
26
16°7 mmFeb
25
18°7 mmMar
25
20°15 mmApr
30
21°42 mmMay
68
21°136 mmJun
120
20°181 mmJul
150
20°166 mmAug
150
19°132 mmSep
100
18°54 mmOct
61
16°14 mmNov
33
15°10 mmDec
Water (estimated flow)Air (average) Rain (mm)Best months

From about 25 m³/s in the lowest month to 150 m³/s in the highest. An estimate: the monthly flow is modelled from the lowest and highest months of WaterGAP (RiverATLAS, 1971–2000) and the rain and snow along the river (WorldClim). Dams change the real rhythm. The chip is the average air temperature; below it, the month's rain.

Plan the trip

Plan the trip: boat trips, a bed by the river, 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 basin

Lerma River: the basin in numbers

40,322 km² of land send their water to this river. This is what lives on it.

DammedReservoirs can hold 88% of a year's flow: much of the river is a chain of lakes.
  • 10.8millionpeople live in the basin
  • 267/km²people per km²
  • 2,075maverage altitude of the basin
  • 763mmof rain a year (basin average)
  • 17.4°Caverage air temperature
  • 10%protected areas
  • 0.7%covered by lakes
  • 2.3km³held in reservoirs

What covers the basin

  • 54% Forest
  • 41% Cropland
  • 19% Pasture
  • 9% Towns and cities

RiverATLAS (HydroATLAS v1.0, CC BY 4.0): land cover, people, protected areas, glaciers and dams over the whole basin upstream of the mouth.

Along the river

Lerma River: what you find on the way

  • 12Dams
  • 4Waterfalls

From OpenStreetMap, within 2.2 km of the river. Not mapped is not the same as not there.

Cross-checked with our atlases

Lerma River in our other atlases

What our sister atlases know about the waterfalls on this river, the lakes it flows through, the beaches at its mouth, the mountains where it rises and the islands off its mouth.

  • 1lake on its wayLakeyas
  • 25mountains at the sourcePeakyas

Lakes and reservoirs (1)

Lakes it flows through, by Lakeyas

  1. Lake Chapalakm 583 · 10 m deep1,052km²

Lakeyas is coming soonOpen Lakeyas ↗

Mountains at the source (25)

Within 15 km of the source, by Peakyas

  1. Volcán Teconto14 km away3,121m
  2. Volcán La Silva13 km away3,107m
  3. Volcán Tomasquillo12 km away3,017m
  4. Volcán Texontepec13 km away2,960m
  5. Volcán Tres Cruces7.8 km away2,915m
  6. Volcán Tehualtepec12 km away2,880m
  7. Volcánes Cuates7.0 km away2,841m
  8. Volcán Tepetzingo13 km away2,813m

17 more on PeakyasOpen Peakyas ↗

From space

The source and the mouth, seen from orbit

Lerma River: satellite view of the source
The source14 km across
Lerma River: satellite view of the mouth
The mouth27 km across

Sentinel-2 cloudless 2016 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2016), CC BY 4.0. The glowing line is the river as drawn by RiverATLAS.

Photos

Lerma River in pictures

Lerma 30may2024 02
Avecus · CC0
CASCADA DEL RIO LERMA 2010 (BY LION) - panoramio
LOBITO · CC BY 3.0
Lerma 30may2024 01
Avecus · CC0
LermaSalamanca03
AlejandroLinaresGarcia · CC BY-SA 4.0

Tributaries

Where it flows, and what flows into it

Tributaries (1)

Also: Bolaños River

Where these numbers come from

Name, length, placesWikidata (Q1633955) · CC0
Course, profile, basinRiverATLAS v1.0 (HydroATLAS, Linke et al. 2019) · CC BY 4.0 — followed from the source to the mouth given by Wikidata
FlowWaterGAP (RiverATLAS), 1971–2000 · CC BY 4.0
Climate along the riverWorldClim (RiverATLAS), 1970–2000 · CC BY 4.0
Towns, bridges, damsWikidata · CC0; GeoNames · CC BY 4.0
Along the river© OpenStreetMap contributors · ODbL
ImagesEOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons
Our other atlasesLakeyas, Peakyas — Wikidata · CC0; © OpenStreetMap contributors · ODbL; GeoNames · CC BY 4.0; HydroLAKES · CC BY 4.0; NOAA OISST

Every source and licence is on the data sources page.

The family

Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers or canyons?

Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.

beachesCoastyaFind your beach: sea temperature, sun and swimming month by month.Visit
lakesLakeyasEvery lake on Earth: water temperature, ice, depth and the shore.Coming soonVisit
mountainsPeakyasEvery summit in 3D: summit weather, the 0 °C line, huts and trails.Visit
waterfallsCascadyasEvery waterfall: height, flow month by month and when it roars.Coming soonVisit
islandsIslandyasEvery island from the sea up: size, sea temperature, ferries and 3D.Coming soonVisit
riversRiveryasEvery river from source to sea: the journey, the flow and the basin in numbers.You are here
canyonsCanyonyasEvery canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Coming soonVisit