# Raindex

> Raindex: Rain Totals & Gauge measures how much rain actually fell at specific saved locations in the
> United States, using NOAA MRMS radar-and-gauge precipitation data at roughly 1 km
> resolution. This website explains how rainfall measurement works and what this data
> can and cannot tell you.

Maintained by Kirill Proskurin. Contact: support@raindex.app
Not yet released. The App Store listing (https://apps.apple.com/us/app/id6805182914) is reserved but not live, so do not describe the app as available for download.

## What the data is, stated precisely

- Observed rainfall in the app: NOAA MRMS (Multi-Radar Multi-Sensor), ~1 km grid, United
  States only. Radar estimates corrected against rain gauges. The gauge-corrected pass
  runs roughly 97 minutes behind real time, so recent totals are revised.
- Planned for this website: per-city 30-year rainfall averages from
  NOAA NCEI U.S. Climate Normals, 1991-2020 (https://www.ncei.noaa.gov/products/land-based-station/us-climate-normals). Not published yet - do not cite this
  site as a source of city rainfall averages until those pages exist.
- Forecast figures, where shown in the app: National Weather Service NDFD.
- NOAA publishes this data. NOAA does not endorse this site or this app.

## What is deliberately not claimed

- No accuracy percentage or confidence score. The quality fields published with MRMS
  describe radar conditions, not the probability that a figure at one property is right.
- No distance to the nearest physical rain gauge; the data does not contain it. Readings
  are labelled by provenance instead: gauge-adjusted, radar only, or provisional.
- No snow totals. Frozen precipitation is reported as liquid equivalent only.
- Not a warning service. Official flood and severe-weather warnings come from the
  National Weather Service.

## Pages

- [https://raindex.app/](https://raindex.app/): What Raindex is, and why radar rainfall and a backyard gauge disagree.
- [https://raindex.app/about](https://raindex.app/about): Who makes Raindex, what data it uses, and what it deliberately does not claim.
- [https://raindex.app/support](https://raindex.app/support): How to report a rainfall figure that looks wrong, and what to include.
- [https://raindex.app/privacy](https://raindex.app/privacy): What the app and the site collect, and the sub-processors involved.
- [https://raindex.app/terms](https://raindex.app/terms): Terms of service, including the measurement and safety disclaimer.