Where our information comes from

Rare Sights brings together published specialist data and editorially selected information. The sources used depend on the event.

Weather at your selected location

Depending on the location, the sky card uses forecasts from Germany's national weather service (DWD MOSMIX, sometimes via Bright Sky) or MET Norway. Rain, visibility and cloud layers may also come from the supplementary services listed below. The station or model used can change with the location.

Rare Sights selects nearby model points, aligns hourly values and converts units for display. We combine these forecasts with independently calculated Sun and Moon positions to create our own search windows. Forecast data are not live sky photos or confirmed sightings. DWD and MET Norway data are credited under CC BY 4.0 with a licence link; MET Norway does not endorse these search rules.

For some locations or supplementary values, we may also use AEMET, Environment and Climate Change Canada, the Met Office, SMHI, GeoSphere Austria or NOAA/NWS. For Met Office data we select nearby official points, align rain chances to the displayed hour and use the median visibility forecast; these adaptations use data under © Crown copyright / CC BY-SA 4.0. Sources only apply where corresponding values are available.

How are these suggestions made?

We combine hourly forecasts for low, middle and high clouds with the calculated Sun and Moon positions at your location. Patchy middle clouds suggest an iridescence search; partial high cloud suggests a sun-halo search. With a lower Sun and little obscuring cloud, we show a sun-dog search window instead. When the Moon is bright and high enough, suitable cloud conditions can suggest a moon-halo search. In summer twilight at suitable latitudes, limited cloud cover offers a time to look for noctilucent clouds. Dark hours with little cloud suggest a stargazing window.

This is our simple search aid, not another app's formula. These weather models do not provide droplet size or ice-crystal shape or alignment, and they do not detect mesospheric noctilucent clouds. We cannot promise an occurrence or a percentage chance. Times are whole forecast hours.

The short-term aurora cue combines NOAA OVATION at the nearest model grid point with darkness and low cloud cover at the selected location. It is not a local visibility probability. The WMO sources explain the optical phenomena; our thresholds are our own cautious search filters.

Solar eclipses

Eclipse dates and the displayed paths of totality are based on published eclipse calculations from NASA's Goddard Space Flight Center. The path shows where the total phase is calculated to occur. Clouds can still obscure the Sun within the path.

Eclipse Predictions by Fred Espenak, NASA/GSFC

Meteor showers

Peak dates, broad viewing regions and predictable moonlight for the listed showers come from the American Meteor Society's annual calendar. Actual activity and weather can differ; no meteor sighting is guaranteed.

American Meteor Society — Meteor Shower Calendar

Lunar eclipses

The eclipse type, date, global maximum and broad visibility region come from NASA/GSFC's lunar eclipse catalog. Whether the Moon is above the horizon during the partial phase needs a check for your location.

Eclipse Predictions by Fred Espenak, NASA/GSFC

Maps

Our maps use data from OpenStreetMap contributors. Map locations and boundaries can differ from conditions on the ground.

Other event information

Depending on the event, we use publicly available information from specialist organisations, authorities and local organisers. Dates, access and conditions can change; check current local information before travelling.

Accuracy near the path edge

NASA estimates that the northern and southern edges of the path of totality may vary by approximately 1–2 km because the Moon's surface is uneven. We therefore mark places close to the calculated edge with care. Farther inside the path, this edge variation does not affect the classification.