  Numerous weather parameters affect the occurrence and amount of rainfall.
Therefore, it is important to study these parameters and their interdependency.
In this paper, different weather and time-related variables -- relative
humidity, solar radiation, temperature, dew point, day-of-year, and time-of-day
are analyzed systematically using Principal Component Analysis (PCA). We found
that four principal components explain a cumulative variance of 85%. The first
two principal components are applied to distinguish rain and no-rain scenarios
as well. We conclude that all 7 variables have similar contribution towards
rainfall detection.
