**Throughout history, many societies and individuals have believed that the moon has an influence on weather and climate. In fact, scientists have observed a correlation between rainfall variations, thunderstorm frequency, daily pressure fluctuations, hurricanes, cloud cover and the phases of the moon.

In certain parts of the world, the occurrence of a lunar component in the daily temperature is comparatively well known, but extremely small and difficult to detect. The lack of accurate, global measurements on a daily basis has until recently made it difficult to clearly identify this lunar influence on planetary temperature.

A new set of daily satellite data now makes it possible to determine the influence of the phases of the moon. In the period from January 1979 to August 1994, global temperature anomalies in the lower troposphere were measured based on the microwave emission of molecular oxygen. The phases of the moon were determined for each day by the mean angular difference between the apparent longitudes of the moon and the sun. A comparison with the temperature anomalies shows a linear relationship between them and the moon phases over the last 15 years. For example, it is on average 0.02 K colder in the lower troposphere at new moon than at full moon. Furthermore, the warmest daily temperatures over a synodic month (29.53 days) coincide with the appearance of the full moon.

The existence of an identifiable relationship between the phases of the moon and the global temperature raises the question of its cause. There are lunar disturbances of the Earth’s magnetic field, lunar modulations of meteoric dust and tidal forces on the atmosphere, which influence the position of the subtropical high-pressure belt, for example. In particular, reflected sunlight and infrared radiation from the lunar surface, which is intensified at full moon, must also be taken into account.

These results not only confirm the suspicions of many past scientists but also indicate that global temperature measurements are now quite accurate.

(Science 267, 1481 [1995])

The edited text appeared in Sterne und Weltraum 35 No. 6 [1996], page 430