Lake Mead water level chart
By Mike, independent developer behind zovo.one. Data checked Sep 21, 2026.
Lake Mead stood at 1,038.22 ft on September 20, 2026, the lowest daily pool elevation Reclamation has recorded since the reservoir first filled; of 33,469 daily readings since 1935-02-02, the 811 that are lower all fall in the initial filling years.
Where today sits in 91 years of readings
Reclamation's latest daily reading is 1,038.22 ft on September 20, 2026, and it is the lowest in the file since the reservoir first filled. Of the 33,469 daily readings going back to February 2, 1935, 811 are lower. Every one of those 811 days falls between February 2, 1935 and April 22, 1937, when the reservoir was still filling for the first time and had never been full.
That phrase, since the reservoir first filled, needs a boundary, and the boundary is ours rather than Reclamation's. This page uses 1942-01-01. Reclamation's file shows Lake Mead first passing 1,220 ft on July 24, 1941, so readings before the cutoff describe a reservoir filling for the first time, not one being operated. It matters because the whole-record minimum is much lower, 670.00 ft on February 2, 1935, and today is 368.2 ft above that. Nobody should read today's figure as the lowest the lake has ever been.
For 09-20 specifically, the file carries 92 years of readings and today's ranks 3 lowest among them. The lowest ever recorded on this date is 923.00 ft, in 1935, and today sits 115.2 ft above it.
Where the line sits against the operating landmarks
The three dashed lines on the chart are published elevations, not chosen ones. Full pool at 1,229 ft is the top of the operating range. Minimum power pool at 950 ft is the line below which Hoover Dam stops generating hydropower. Dead pool at 895 ft is the lowest elevation from which water can still pass the dam.
Reading a chart against those lines is the part most level pages skip. A reservoir sitting 88.2 ft above minimum power pool is in a different operational state from one merely below average, and the chart shows how rarely the line has been down here.
Two Reclamation series, and what neither of them states
This chart plots Reclamation's daily pool elevation for Lake Mead, site 921. The live figure elsewhere on this site comes from Reclamation's Lower Colorado hourly report, which publishes the end-of-period reading many times a day. Both are Reclamation, and they are still two different series: a daily value and an hourly one will differ by a tenth of a foot or so on any given day, which is a difference in sampling rather than a disagreement.
Worth knowing before you compare this number with one from somewhere else: Reclamation's catalog entry for this series carries a field for the vertical datum and this page makes no claim about what belongs in it, because no value is published there. Lake Mead elevations are conventionally quoted against a Reclamation datum rather than a national one, and sites that print a Mead figure rarely say which. So this page does not assert a datum. It plots the Reclamation series, labels it as the Reclamation series, and links the file so you can check any figure against the source.
Mead does not have much of a season, and that is the point
Upstream reservoirs fill on snowmelt and draw down through autumn, which gives them a yearly rhythm you can see in the line. Mead sits below Hoover Dam and is governed by release schedules rather than by a spring freshet, so its year does not have that shape.
Count the 84 complete calendar years from 1942-01-01 onward and ask only which month carried each year's highest reading. The winner is February, and it wins only 22 of 84 years, 26.2 percent. The rest scatter: December takes 17, July takes 16. The annual low is just as spread, with January the most common at 15 years.
Compare that with Lake Powell upstream, where July carries the annual high in 21 of 45 years, 46.7 percent of them. Powell has a season. Mead has an operating schedule.
The practical consequence is the opposite of what people usually assume. On a snowmelt reservoir a low reading in autumn may be ordinary for the date. On Mead there is no reliable seasonal excuse, so a low reading is closer to face value, and the rank against the whole record above is the honest way to read it.
Check any elevation against the record
Pick a date and get the pool elevation Reclamation recorded that day, plus where it ranks among every reading in the file. Or enter an elevation and get how often the lake has been that low and when. Both answers are computed in your browser from the same series the chart draws. Nothing is sent anywhere.
Questions about the Lake Mead record
How far back does this chart go? To February 2, 1935, the first row in Reclamation's daily file for Lake Mead. The file carries 33,469 daily readings through September 20, 2026.
Is this the lowest Lake Mead has ever been? No. The lowest reading in the whole file is 670.00 ft on February 2, 1935, during the years the reservoir was filling for the first time. Today is the lowest since it first filled, which is a different and narrower statement.
What was the highest? 1,225.83 ft on July 24, 1983, which is 3.17 ft below the 1,229 ft full-pool line.
Why does this chart differ from the live reading elsewhere on the site? Because they are different series. This chart plots Reclamation's daily pool elevation for site 921. The live reading comes from Reclamation's Lower Colorado report, which publishes hourly readings for Hoover Dam. Both are federal, neither is wrong, and they are not the same measurement.
How often does it update? The file is refetched and every figure on this page recomputed on each build, which runs daily.
Where these numbers come from
Every figure on this page is computed in code from one file, Reclamation's complete daily pool-elevation record for Lake Mead, site 921. The build fetches it, parses 33,469 daily readings, drops the sentinel values Reclamation uses for a missing day, and computes the extrema, the counts and the rankings from what is left. None of the numbers is typed by hand, and none is carried as a constant that could go stale, which is exactly what went wrong with the previous record-low figure this site published.
The rankings are computed over the whole file rather than over a window. That distinction matters. A minimum found inside a date range only tells you the minimum of that range, so this page establishes the record by measuring the entire population, which is the only honest way to use the word lowest.
The published landmark elevations, full pool, minimum power pool and dead pool, come from Reclamation and are constants because they describe the dam, not the water.
Want today's reading rather than the record? The Lake Mead water level page carries the live figure, the percent full and the 24 hour move. Upstream, the same chart for Lake Powell covers the reservoir that feeds this one, and the two records are worth reading side by side. Off the Colorado entirely, the Lake Travis water level chart plots the Texas Water Development Board's daily file the same way.
Levels are point-in-time readings and can lag real conditions, confirm ramp and hazard status with the lake operator before heading out. Not affiliated with any government agency, data is republished from public USGS, CDEC, and USBR feeds.