Recently, American and Spanish researchers published a curious study concerning rain-making rituals during drought periods. According to the authors, there is a correlation between prayers and rainfall, mainly in arid regions. However, this does not indicate that these rituals cause the precipitation.
The Largest Study on Rain Rituals
First of all, let us recall that rituals and other processions to bring down rain have existed since prehistoric times. They are found around the world, particularly within agricultural civilizations, when drought endangers crops and wells. For example among the Berbers, the Tlaɣunja is paraded, a large wooden spoon dressed like a bride. In Thailand, we can cite the traditional cat parade (Hae Nang Maew Festival), during which a feline is carried around while it is splashed with water in order to trigger showers.
In May 2026, studies by Yale University (United States) and the University of Murcia (Spain) were published in the Quarterly Journal of Economics. The study, conducted by specialists in economic history as well as energy and environmental markets, is none other than the most recent and largest research on rain-making rituals.
“We present a model in which a religious leader tries to persuade followers to believe in it. Praying for rain is effective only where the risk of precipitation during a drought period increases over time; the prayer therefore has a higher chance of succeeding when people desire rain the most.”, the study states.
The Hazard Rate Effect
In fact, the researchers cross-referenced the traditions of more than 1,200 ethnic groups around the world with very precise climate data. According to the results, the weather follows an increasing hazard rate in arid regions. This means that the longer the spell of consecutive dry days, the higher the statistical probability that it will rain the following day.
The study authors stated that rituals and other prayers never appear at the onset of a drought but rather when the climatic episode becomes critical and unbearable. At that precise moment, the natural probability of a shower occurring is already at its maximum. The work shows that a prayer launched during a period of extreme drought artificially increases by 71% the apparent probability of rain falling in the following days.
To validate their model, the researchers added the analysis of 200 years of archives—from the eighteenth to the twentieth century—of the Cathedral of Murcia, a very arid region of Spain. In fact, they compared the exact dates of the church’s official orders calling for rain prayers (the “rogations”) with the actual meteorological data of the time. Indeed, the correlation appeared perfect, insofar as the Church launched the rituals at the precise moment when the historical drought had accumulated to bring the return of rain imminent.
A Question of the Illusion of Efficacy
In economics, rain-making rituals are studied as “instrumental beliefs.” The aim here is to understand how behaviors that could be deemed irrational can actually help agricultural societies. These societies therefore use the rituals to manage their economic stress, structure their harvest calendar, and maintain social cohesion in the face of climate-induced difficulties.
For the authors, human societies living in arid environments have developed an intuitive, albeit biased, understanding of the cycles of climatic probabilities. Thus, ethnic groups tied to this specific climatic profile have 47% more chances of developing rain-prayer rituals than others, since the illusion of efficacy is mathematically the highest there.
Article prepared with the help of AI · Our method
