This is comparison of two 5-year monthly rain periods 100 years apart. This rainfall record is from the National Oceanic and Atmospheric Association (NOAA).
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.