Dim ond pum ysgol yng Nghymru sydd wedi cael eu henwi fel rhai sydd wedi eu heffeithio gan RAAC, sef Ysgol David Hughes ac Ysgol Uwchradd Caergybi ar Ynys Môn; Ysgol Maes Owen yng Nghonwy; Ysgol Trefnant yn Sir Ddinbych ac Ysgol Gynradd Eveswell yng Nghasnewydd, a hynny o gymharu â mwy na 230 o achosion yn Lloegr a 39 o achosion yn yr Alban. Mae pob ysgol yng Nghymru ar agor i ddisgyblion.
Five schools, Ysgol David Hughes and Ysgol Uwchradd Caergybi on Ynys Môn, Ysgol Maes Owen in Conwy, Ysgol Trefnant in Denbighshire and Eveswell Primary in Newport, have been identified as being affected by RAAC, compared to more than 230 in England and 39 in Scotland. All Welsh schools are open to pupils.