As with any other astronomical phenomenon, meteorological conditions are crucial for observing eclipses. The presence of cloud cover or fog may prevent them from being visible, especially if they occur close to the horizon, as is the case with the eclipses of 2026 and 2028.
Although Spain is popularly considered a sunny country, its meteorology is complex and is influenced by orography, vegetation and prevailing winds. Below are some comments on the average climatic conditions in the regions within the path of totality on the days of the eclipses. This should not be taken as a weather forecast, as such forecasts cannot be made so far in advance, but rather as guidance on what we are most likely to encounter on those dates. The State Meteorological Agency (AEMET, https://www.aemet.es) provides accurate weather forecasts several days in advance. It is advisable to consult these forecasts in the days leading up to the event to determine whether the observation location will have favourable sky conditions.
Eclipse of 12 August 2026
The path of totality will enter from the north-west of the Peninsula and move towards the east coast, also covering the Balearic Islands. Figure 1 shows the average cloud cover for the month of August during the period 2001–2017.
As can be seen, cloud cover tends to be greater in the areas along the Cantabrian coast. Orography plays a role in this, as the humid air brought inland by the northerly winds from the Cantabrian Sea tends to become trapped in the mountainous areas of the Cantabrian Range. Mountain systems such as the Cantabrian Range itself, the Iberian System and the Central System also tend to produce convective cloud cover, as they lift the air and cause the moisture it carries to condense as it cools.
Vegetation also plays a role in meteorology, as forested areas absorb the Sun’s heat, contributing to the formation of convective clouds when atmospheric conditions allow.
In view of all this, the areas with the most favourable climate for observing the eclipse in totality are the northern part of the Central Plateau and the Ebro Valley.
Eclipse of 2 August 2027
The path of totality for this eclipse will pass through the extreme south of the Peninsula and North Africa. In Spain it will therefore be visible from Ceuta and Melilla, much of the province of Cádiz, a large part of the province of Málaga, and the southern areas of the provinces of Granada and Almería. As shown in Figure 2, these are regions with a low probability of cloud cover, although it is slightly higher in western Cádiz due to the ingress of humid air from the Atlantic. The maximum of the eclipse will occur at around 11 a.m., when the Sun will be quite high in the sky, making observation easier.
Eclipse of 26 January 2028
The path of annularity for this eclipse will cross the Peninsula from south-west to north-east and will also be visible in the Balearic Islands. It will occur close to the horizon and in winter, so the meteorological conditions typical of the season may hinder its observation.
Figure 3 shows the average cloud cover for the date. The most favourable areas can be seen in the Guadalquivir Valley, in the provinces of Huelva, Seville, Cádiz and Córdoba. The presence of the Baetic System worsens conditions in south-eastern Andalusia. Cloud cover also increases as we move into Castilla-La Mancha, decreasing again upon reaching the Ebro Valley.
