Weather is the main variable astronomy cannot lock in years ahead. Climate history can tell us what is typical around Cádiz in early August, but it cannot tell us whether a specific beach, hill or town will be cloud-free at 10:47 on 2 August 2027.
Use climatology for broad planning
Long-term temperature, sunshine and cloud statistics are useful when comparing Spain with other parts of the eclipse path. They can also help distinguish Atlantic and Mediterranean influences within southern Spain.
Do not turn a historical percentage into a forecast
A statement such as “90% chance of clear sky” based on climate history is not the same as a 90% meteorological forecast for eclipse morning. Public communication should make that distinction explicit.
Make the real decision close to eclipse day
In the final week, use AEMET and other reputable numerical forecasts to compare cloud layers, wind and local coastal effects. In the final 24–48 hours, satellite imagery and updated short-range models become increasingly useful.
Build mobility into the weather plan
A weather backup only works if the alternative location is reachable. If road restrictions or congestion make relocation unrealistic, it is better to know that in advance than to discover it when clouds appear.
Wind also matters
Even with a clear sky, strong wind can affect telescopes, tripods, shade structures and comfort. Secure equipment and avoid turning a large umbrella or temporary shelter into a hazard.