Solar eclipse on 14 October: respite from the blazing heat

On Saturday, 14 October 2023, at the heart of the Space Festival at Europe’s spaceport, an annular solar eclipse¹ occurred in French Guiana. It began at 14:47 (local time), with the degree of obscuration² peaking at 16:46, and ended at 17:36.

To what extent did this phenomenon impact the air temperature in French Guiana?

Temperatures in French Guiana are at record levels during this time, with record heat peaks observed mainly in the afternoons. The annular solar eclipse on Saturday, 14 October brought a slight drop in temperature across the whole region between 15:00 and 17:00. However, temperatures had reached extremely high levels just before the eclipse, so the drop in temperature that occurred at the height of the eclipse was hardly noticeable.

The solar eclipse therefore began at the hottest moment (14:47) on one of the hottest days in French Guiana since meteorological observations began. It was therefore difficult to fully appreciate the drop in temperatures seen during the eclipse. However, around the obscuration peak (at 16:26 pm), we observed lower temperatures than those recorded the previous day or the following day at the same time. This drop, which varied from one sector to another, was generally around one degree.

The map above shows the difference in temperature at 17:00 between the one recorded on 14 October and the ones recorded in the surrounding days (average of the previous day's temperature and that of the following day at 17:00). This variation is explained by the slight disparities in cloud cover observed in the various sectors. The greatest difference was measured in the municipality of Roura.

For more information, visit the French Guiana Météo-France website.

¹An annular eclipse means that the moon is located entirely within the solar disc, which will therefore appear as a luminous ring. 

²The degree of obscuration is the fraction of the sun's disc that will be masked by the lunar disc.