Water is the essence of life.
A machine that makes it should work like a utility.
A water machine cannot be a fair-weather device. It has to deliver day after day, season after season, in the places that need it most. That calls for a utility-grade test, so we propose one:
Green means the standard is met; red means it is not. You can tighten or relax the standard yourself below. We publish where the WaHa Vaporator® works and where it does not, and we invite every vendor to do the same.
MVC / condensing: the conventional approach, chilling a surface until dew forms; most machines sold today. The WaHa Vaporator® uses a sorbent engine instead, which is why the maps differ.
City search and live monthly reports use weather data by Open-Meteo.com (CC BY 4.0). Reference maps and statistics: ERA5, Copernicus Climate Data Store (Hersbach et al., 2023, DOI 10.24381/cds.adbb2d47).
Scroll to zoom, drag to pan, or pick a region. Move across the map for the nearest mapped city; click a city, or search below, for the full monthly report on any location on Earth.
Test any machine VENDOR SELF-TEST
Enter any machine's operating envelope, from a spec sheet or your own lab, and the next city report includes it beside the WaHa Vaporator® and the MVC class, judged by the identical utility standard. Two humidity numbers are needed: the driest air in which the machine still delivers its full rated output, and the point where it stops producing. Output between the two is taken as a straight line, and a day counts only when the machine would deliver at least 90% of rated. Rating-point humidity (30 °C / 60% RH is about 16 g/kg) is not the first number; most machines hold rated output some way below it, and a chamber test is the way to find out how far.
Country report
Exact results for any country, precomputed from the full production analysis: viable land share, addressable population, and water-stressed population served, at whatever standard the slider above is set to.
Portfolio analysis
One site per line, up to 15 (city names, add country for common names). Each site gets the full four-year test; the table below tells you which sites meet the utility standard and where the weak seasons are.
City
Monthly reliability
Share of days in each month (2021 through 2024) meeting the 90% daily production standard. The dashed line marks the 90% utility-grade reliability threshold.
Your local climate against each operating envelope
Monthly mean mixing ratio (bars, left axis) with each technology's minimum threshold, and monthly mean 2-meter temperature (line, right axis).
Every day, on one chart
Each dot is one day from 2021 through 2024: its mean temperature across the bottom and its mean moisture up the side (mixing ratio, the grams of water vapor carried in each kilogram of air). The shaded boxes are the operating envelopes: a machine delivers at least 90% of its rated output on the days inside its box. Gray curves are relative humidity at sea-level pressure, for orientation. Hover a dot for its date.
Estimated energy cost per liter
Mean energy cost (kWh per liter), shown only for months that meet the 90% reliability standard. A system that cannot reliably produce water in a month has no meaningful energy cost, so those months are blank. Curves are WaHa engineering estimates derived from measured performance data.
Compare the technology behind these results
Viability depends on the platform. See how the WaHa Vaporator® sorbent engine compares with MVC and condensing AWGs across energy, water quality, and operating envelope.
See the AWG platform comparisonMethodology
The two envelopes on this map
Two-point envelopes in city reports (September 30, 2026). The map above was computed at the single floors in the table. City reports, portfolio runs, and the vendor self-test now describe each machine with two humidity numbers, the driest air at which it still delivers full rated output and the point where production stops, and grade a day as delivered only when output would be at least 90% of rated. On that basis the city reports use 0.95 g/kg for the WaHa Vaporator® (full output to 1 g/kg; the stop point is provisional pending chamber confirmation) and 14.3 g/kg for the condensing class (full output to 15 g/kg, zero at 8). The map will be regenerated on the same rule.
How we built this map: the seven steps
Step 1: Start with the world's weather diary. We use ERA5, a dataset built by Europe's weather agency that replays the actual weather of the past, everywhere on Earth: every real measurement humanity collected, blended with physics into one seamless record. The planet is divided into squares about 27 kilometers on a side, like pixels in a photograph, and ERA5 reports the conditions in every square, every day. It is the reference dataset of modern climate science, it is free, and anyone can download the exact same numbers we did. Nothing on this page rests on our say-so.
Step 2: Pull out the two numbers a water machine cares about. For every square, for every one of the 1,461 days in 2021 through 2024, we extract the day's average temperature and the day's average moisture: the mixing ratio, literally how many grams of water vapor ride along in each kilogram of air. We use it instead of relative humidity because relative humidity swings with temperature even when the water in the air has not changed. A machine harvests grams, not percentages, so we count grams.
Step 3: Write down what each machine needs. Every machine has an operating envelope, its comfort zone: the driest air it can pull water from, and the temperatures it tolerates. The two envelopes above are the ones painted on this map. Any company's machine can be tested the same way; it need only state its envelope.
Step 4: Grade every day, pass or fail. For each square and each day: were the day's average conditions inside the machine's comfort zone? Pass or fail, no partial credit, no excusing a bad season. Over four years every square earns an attendance record out of 1,461 days.
Step 5: Apply the utility bar. A place counts as viable only if the machine passed at least 90% of its days, roughly nine days in ten, through every winter and summer on record. That is the difference between a water supply and a water gadget. Green clears the bar; red does not. Four years means no machine passes on one lucky mild year.
Step 6: Count honestly. Map squares shrink toward the poles, so each is weighted by its true area; otherwise empty Arctic squares would outvote populated tropics. Antarctica is excluded from every statistic and shown gray.
Step 7: Ask where it matters. We overlay the World Resources Institute's water stress grades and a population count for every square. The green-and-red map becomes the numbers that matter: what share of water-stressed land each machine serves, and how many of the 4.36 billion people living under water stress sit inside its green squares. For the WaHa Vaporator®: 4.07 billion.
How each square gets its color: the full checklist
Each square gets four weather check-ins a day, at the same four fixed moments worldwide, six hours apart, so no place is measured only at its most flattering hour. Each check-in provides three raw ingredients: temperature, air pressure, and the dew point, which is how weather science writes down moisture; the higher the dew point, the muggier the air.
A textbook formula (Bolton, 1980) converts dew point and pressure into grams of water per kilogram of air. Pressure gets a say because air thins with altitude: a kilogram of Denver air fills more space than a kilogram of Mumbai air, and the formula accounts for it, so mountain and coastal machines are judged on the same honest basis.
The four check-ins become one daily average, because that is how the machines work: they run around the clock and fill a tank over the whole day, so a dry afternoon can be repaid by a humid night. We also checked the harsher version, grading all four moments separately, as one of the standard's built-in stress tests; the picture does not change in any way that matters.
Then the actual test, two questions long: was the day's average moisture at or above the machine's declared floor, and was the day's average temperature inside its declared range? Yes to both and the day passes. There is no step where anyone's opinion enters.
Repeat for 1,461 days and count. At least 90% of days passing, the square turns green; below, red. Mostly-ocean squares stay white, Antarctica is gray and outside every statistic, and totals weight each square by its true size on the globe.
The checklist is short enough to publish, and that is the point: four check-ins, one textbook conversion, one daily average, two yes-or-no questions, a four-year count, honest bookkeeping. If someone reruns it and gets a different map, one of us has made an arithmetic error, and it can be found.
Reproduce our results
Every number on this page comes from public data and documented assumptions: a free Copernicus account, the WRI Aqueduct download, and WorldPop are sufficient. The reference implementation, retrieval, pass logic, statistics, and map rendering, is published as open source under the MIT License: github.com/wahainc/awg-viability-standard. Any vendor, customer, or researcher can run the same test on any machine's declared envelope; adding a machine is a one-line declaration.
This map is Part I of something larger
Where a machine works is the first of four questions a buyer should get answered the same way from every vendor. We have proposed an open standard family for the industry, and we hold ourselves to it: Part I, where does it work (this page); Part II, what does it truly cost to run, counting every energy flow crossing the machine boundary, because free heat changes the invoice, not the thermodynamics; Part III, what comes out of the tap, tested at the point of dispense; and Part IV, does the machine show up, verified in the field over at least a year of telemetry-verified operation. Alongside them, two disclosure schemas, cost of ownership and environment and siting, standardize what vendors report so buyers compare on identical terms.
Take it further
If you are buying
Run your own city above. Then ask every vendor you are evaluating for the same four answers: where it works under a 90/90 daily standard, its total energy with every input counted, its water quality at the tap, and its field record. Vendors with good answers will not mind the questions. See the full platform comparison and the questions to ask any vendor.
If you are a vendor
Publish your operating envelope under the same test. The reference implementation is open; adding a machine is a one-line declaration. We have published where our machine works and where it does not. Join us.
If you are the industry
This methodology, its reference results, and the full four-part proposal are available for review and adoption. We built it to be taken over, not owned. Contact WaHa to engage.