AERMOD modeling that just works.
Stop wrestling with file formats and waiting days for results. Cumulus puts air quality analysis at your fingertips—faster, simpler, and more reliable than ever before.
What You Get
Everything you need for modern air quality analysis
Set Up Projects Visually
Click on a map to place your sources and receptors. See your project take shape in real-time. No more manual coordinate entry or guessing if your input file is correct.
Preview Before You Run
See wind patterns and dispersion impacts instantly. Catch issues before committing to a full model run. Make confident decisions about receptor placement and project scope.
Terrain Data Automatically
No hunting for DEM files or managing gigabytes of terrain data. We pull high-resolution elevations directly from USGS sources—you just define your project area.
Meteorology On Demand
Search our curated library of AERMET-ready datasets by location. Download exactly what you need. Distance-sorted results mean you find the closest station in seconds.
Results in Minutes, Not Days
Large receptor grids that used to take days now complete in minutes. Automatic parallelization handles the complexity—you get your results faster at a fraction of the cost.
Regulatory-Ready Documentation
Every result includes complete documentation of inputs and assumptions. Reproducible calculations with full audit trails. Submit with confidence knowing regulators can verify every detail.
Why Cumulus is Different
Built from the ground up for the way you actually work
No More File Wrangling
Traditional AERMOD workflows mean editing text files, debugging cryptic error messages, and hoping you got the format right. Cumulus handles the complexity—you focus on the analysis.
Modern Performance
We rebuilt the slow parts from scratch. What used to take overnight runs now completes while you grab coffee. Scale to thousands of receptors without breaking a sweat.
Built for Teams
Share projects, review results, and maintain consistency across your organization. Everyone works from the same data with the same assumptions—no more version control nightmares.
Trusted by Environmental Professionals
EPA-Validated Algorithms
Same science, better tools. All calculations follow EPA guidelines and produce results identical to the official AERMOD binaries. We've done the verification so you don't have to.
Complete Transparency
See exactly how every number was calculated. Access raw input files, intermediate results, and calculation provenance. No black boxes—just reliable, explainable science.
Always Reproducible
Run the same analysis twice, get identical results. Archive projects with complete documentation. Meet the highest standards for regulatory submissions and peer review.