The usual benchmark for effect of loading is the tides, since they change fast relative to tectonic loading and can be calculated in many case. There is only a weak correlation of tides with earthquakes.

There have also been weak correlations noted with the filling of large reservoirs and earthquakes, which might be loading effects or might arise from affecting the ground water within the faults.

Third, there have been distinct swarms of earthquakes arising from injection of fluid via deep boreholes, where we know the fluid penetrate the faults.

So cause and effect is not always simple to calculate, but I suspect this latest earthquake has little to do with rainfall.