That’s slightly misleading, the RDU record has been broken (previously 9.11”). It was set in 2024:
https://www.wral.com/archive/21561538/
The Raleigh record is what those tweets are speaking to and it is taking into account the switch to RDU as the reporting site in 1945, and observations at the previous sites which obviously go further back. So there is no RDU record pre-1945 as that site didn’t exist. But as shown, reporting site or not, tomorrow’s rain could shatter all records for the Raleigh area in July. My >13” total already has, if my site was official! It’s the wettest month I’ve had in 8 years of running my station