I'm not an expert, but it's a very complex global system with moisture in the atmosphere sometimes falling as rain/snow, collecting in rivers and lakes, going into ground water/aquifers, flowing into the oceans, and sometimes just staying as moist air. If one area isn't getting it's usual rainfall, quite often another area is getting more, but it can also be that the moisture is just in other parts of that complex system. A lot is driven by high- and low-pressure systems, air temperature, water temperature, etc.

In my area of southern California, we've had some major, extended droughts. But the rising temperature of the Pacific has caused the air to hold more moisture, and we've also had some "atmospheric river" storms that drop insane amounts of rain. So even though we get an average of 13 inches of rain a year, we got more than 13 inches in just February, and we're up to almost 31 inches for the season. It wouldn't be surprising if we didn't get anymore until late in the year though.

Some of that rain went into snowpack, some into reservoirs, some into ground water, but we're close to the coast and all of it will go back to the ocean. Did we get rain that would normally have gone elsewhere, or was it rain that wouldn't normally have formed? I think it's likely hard to say, but maybe there are meteorologists or others who know more reading this.