Today's census figures will focus on international migration, ethnic groups and religion - and the Welsh language.
Some parents like Rhian Cecil hope it'll lead to more Welsh medium and bilingual schools over the next ten years.
"It's really important for us as Welsh speakers to be stood up and counted".
"Hopefully all the figures can help local councils create more provision".
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Rain overnight turning light and patchy in the morning.
Most of us will have a pleasant and dry evening with a few late sunny spells, though the odd light shower is possible.
The Eisteddfod's intention to visit an area must be proclaimed at least a year and a day before the beginning of the festival.