Data & transparency

Viewpoint shows forecasts — cloud cover, weather, sun and moon positions — to help you plan. This page explains where that data comes from and, just as importantly, what it cannot tell you.

Where the data comes from

• Weather forecasts (cloud cover, temperature, wind, precipitation) come from a third-party weather service that serves numerical weather-model output, fetched through our backend.
• Sun and moon positions are calculated on the device from astronomical formulae — these are geometry, not a forecast, and are reliable.

Data sources

Weather and satellite data are provided by Open-Meteo (licensed under CC BY 4.0). Beyond that, Viewpoint draws on night-light and Moon imagery from NASA, the Sun picture on the Explore map from NASA/SDO and the AIA, EVE and HMI science teams (public domain), the Milky Way core marker from the Hubble image of M51 by NASA, ESA, S. Beckwith (STScI) and the Hubble Heritage Team (STScI/AURA) (CC BY 4.0), the Kp index and aurora model from the NOAA Space Weather Prediction Center, meteor shower dates, radiants and rates from the International Meteor Organization (IMO), Working List of Visual Meteor Showers (used with the IMO’s permission), meteor shower peak times and the showers the IMO does not list from NASA’s Meteoroid Environment Office, and coastlines and borders from Natural Earth. In the app, open Settings, then Data sources, or the … menu on the Conditions page, to see what each source supplies, its licence and a link to it. The same list is on the web app under Settings. OpenStreetMap contributors are credited there only when a place name or map from OpenStreetMap is shown. Explore’s map on iPhone, iPad and Android comes from Google Maps while you’re online with the Max plan, and from OpenStreetMap otherwise; on the web app it comes from Google Maps (terrain, satellite or standard); Google’s logo and its own attribution are always on the map, and nothing in the app covers them. The 3D view, on the phones and on the web app, draws Google Photorealistic 3D Tiles (© Google and its data providers, credited on screen in the 3D view’s attribution). On the web your browser loads them directly from Google and we do not proxy, store or cache them. Where there is no photorealistic coverage, the view uses an open-terrain fallback built from AWS Terrain Tiles and Sentinel-2 cloudless imagery by EOX (CC BY 4.0). The Moon, Milky Way and star imagery in the 3D sky comes from NASA (public domain), as on the 2D Explore map.

What a forecast can and cannot do

Cloud and weather figures are the output of mathematical models run on a grid. That has real limits:

• Grid resolution. A model reports one value for a whole grid cell — often kilometres across. A valley, a ridge, or a single cloud bank smaller than the cell is not resolved. Viewpoint shows the active model and its resolution (for example ICON-D2 2.2 km) so you can judge how fine the data is.
• Terrain. The models do not fully account for local terrain — shadowing, valley fog, a peak catching light the forecast cannot see.
• Time. Accuracy falls off the further out the forecast reaches.

Use it as a guide, not a guarantee

All forecasts, environmental data, and spatial calculations in Viewpoint are provided on an “as-is” and “as-available” basis. They are planning aids. Real conditions in the field can and do differ.

Your safety is your responsibility. Do not rely on Viewpoint for decisions where weather or terrain carries real risk — check authoritative local forecasts and conditions, and use your own judgement. See the weather-accuracy disclaimer.