Great example, as clearly, the indians understood weather better than we do, they observed it daily, and wouldn't waste time burning stuff and chanting if it did not work. The main point I like to make is, neither you, nor I, nor the smartest scientists in the world know the first damn thing about how the weather works.
Yes we do, we know a vast amount about the weather, both from years of observation and from access to science that was not available to the indians. We have a strong understanding of the physical processes involved (convection, conduction, radiation, evaporation, condensation, etc.), and we are able to predict weather patterns with considerable confidence.