Nationally our rainfall has grown by about .16 of an inch or about 1/6 of an inch per month.
Some areas of the country are wetter and other areas are dryer. These rain and temperature changes have always been going on through the centuries. Any random 5-year chart shows the same type of variability. Some areas do experience multi-year or even multi-decade extra or too little rainfall. The weather varies, from year to year and century to century.