Every school has a number of INSET (In Service Educational Training) days per year. These days are for staff training and are important for the development of teaching methods.
The decision on the dates of inset days is made by the individual head teacher and governing body of that school. Any queries should, therefore, be directed to the individual schools.
View details of school inset days below:
Abercynon Community Primary School
Monday 05 January 2026
School is closed to pupils for staff training
Monday 20 July 2026
school will be closed to pupils for staff training
Aberdare Community School
Aberdare Park Primary School
Aberdare Town C in W Primary
Blaengwawr Primary School
Bodringallt Primary School
Monday 26 January 2026
DCF Cluster Collab
Bryncelynnog Comprehensive School
Cardinal Newman RC Comprehensive School
Cefn Primary School
Thursday 07 May 2026
INSET Day closed to all pupils
Coedpenmaen Primary School
Craig Yr Hesg Primary School
Thursday 07 May 2026
INSET Day- Closed to all pupils
School will be open as a Polling Station
Cwmclydach Community Primary School
Monday 05 January 2026
Inset Day 2
Darran Park Primary School
Monday 05 January 2026
INSET Day for all staff - school is closed to all pupils
Darrenlas Primary School
Monday 05 January 2026
Inset Day
Thursday 07 May 2026
Inset Day - School Closed for Senedd Elections
Monday 20 July 2026
Inset Day
Glenboi Community Primary School
Monday 05 January 2026
Inset Day
Gwauncelyn Primary School
Gwaunmeisgyn Primary School
Hendreforgan Primary School
Llanharan Primary School
Monday 05 January 2026
School closed to pupils.
Llanilltud Faerdref Primary School
Friday 19 December 2025
School closed fopr pupils
Friday 17 July 2026
School closed for pupils
Monday 20 July 2026
School closed for pupils
Llantrisant Primary School
Llwyncrwn Primary School
Monday 23 February 2026
School closed for all pupils
Friday 08 May 2026
INSET day
Llwynypia Primary School
Monday 05 January 2026
Training day for all staff.
Maerdy Community Primary School
Monday 05 January 2026
INSET day. School will be closed for children.
Maesycoed Primary School
Monday 05 January 2026
School closed to pupils
Friday 27 March 2026
School closed to pupils
Friday 17 July 2026
School closed to pupils
Monday 20 July 2026
School closed to pupils
Mountain Ash Comprehensive School
Our Lady's RC Primary School
Friday 12 December 2025
Well being INSET day
Parc Lewis Primary School
Friday 19 December 2025
INSET Day
Monday 23 February 2026
INSET Day
Friday 22 May 2026
INSET Day
Monday 20 July 2026
INSET Day
Pengeulan Primary School
Monday 05 January 2026
Cluster Behaviour Development
Friday 27 March 2026
School Inset Day
Penpych Primary School
Monday 05 January 2026
Staff training
Monday 26 January 2026
Treorchy Cluster Inset Day
Penrhiwceibr Primary School
Monday 05 January 2026
School closed for Cluster Teacher Training.
Penrhys Primary School
Friday 19 December 2025
School closed for all staff and children.
Mr. Williams- Headteacher
Monday 05 January 2026
School closed for all children due to staff training.
Mr. Williams- Headteacher
Monday 20 July 2026
School will be closed for all staff and children.
Mr. Williams- Hedateacher
Penyrenglyn Community Primary School
Friday 19 December 2025
School closed for all pupils
Monday 26 January 2026
School closed for all pupils
Penywaun Primary School
Monday 05 January 2026
Staff INSET Day
Perthcelyn Community Primary School
Pontyclun Primary School
Monday 05 January 2026
staff training
Friday 27 March 2026
staff training
Friday 22 May 2026
staff training
Monday 20 July 2026
staff training
Pontygwaith Primary School
SS Gabriel & Raphael RC Primary School
St John Baptist C in W High School
St Margaret's RC Primary School
Friday 12 December 2025
Well being INSET day
St Michael's RC Primary School
Tai Education Centre
Monday 05 January 2026
Day 3-Staff training. Closed to all pupils.
Thursday 07 May 2026
Day 4 - Taff Training - Closed to all pupils.
Ton Infants School
Monday 26 January 2026
Inset Day
Ton Pentre Junior School
Monday 26 January 2026
INSET Day - Only staff to attend.
Monday 13 April 2026
INSET Day - Only staff to attend.
Monday 20 July 2026
INSET Day - Only staff to attend.
Tonysguboriau Primary School
Trealaw Primary School
Monday 05 January 2026
Inset Day
Friday 01 May 2026
Inset Day
Monday 20 July 2026
Inset Day
Tref Y Rhyg Primary School
Treorchy Comprehensive School
Trerobart Primary School
Friday 19 December 2025
School closed for pupils
Monday 13 April 2026
School closed for pupils
Monday 20 July 2026
School closed for pupils
Ty Gwyn Education Centre
Friday 19 December 2025
INSET
Williamstown Primary School
Monday 05 January 2026
INSET day - closed to all pupils
Y Pant Comprehensive School
Ynysboeth Primary School
Monday 05 January 2026
INSET DAY
Ynyshir Community Primary School
Monday 05 January 2026
Inset day for staff training.
Ysgol Gyfun Cwm Rhondda
Friday 19 December 2025
Diwrnod HMS - Ysgol ar gau i ddisgyblion INSET Day - School closed to pupils
Friday 13 February 2026
Diwrnod HMS - Ysgol ar gau i ddisgyblion INSET Day - School closed to pupils
Friday 27 March 2026
Diwrnod HMS - Ysgol ar gau i ddisgyblion INSET Day - School closed to pupils
Monday 20 July 2026
Diwrnod HMS - Ysgol ar gau i ddisgyblion INSET Day - School closed to pupils
Ysgol Gynradd Gymraeg Abercynon
Monday 05 January 2026
INSET Training Days
Tuesday 06 January 2026
INSET Training Days
Ysgol Gynradd Gymraeg Aberdar
Monday 05 January 2026
Review of School Development Plan
Ysgol Gynradd Gymraeg Awel Taf
Ysgol Gynradd Gymraeg Bodringallt
Thursday 18 December 2025
HMS - Diwrnod hyfforddi staff. Nid yw'r ysgol ar agor i blant.
INSET - Staff training day. School is not open to pupils.
Friday 19 December 2025
HMS - Diwrnod hyfforddi staff. Nid yw'r ysgol ar agor i blant.
INSET - Staff training day. School is not open to pupils.
Monday 05 January 2026
HMS - Diwrnod hyfforddi clwstwr. Nid yw ysgolion clwstwr Cwm Rhondda ar agor i blant.
INSET - Cluster training day. Cwm Rhondda cluster school are not open to pupils.
Monday 02 February 2026
HMS - Diwrnod hyfforddi staff. Nid yw'r ysgol ar agor i blant.
INSET - Staff training day. School is not open to pupils.
Monday 20 July 2026
HMS - Diwrnod hyfforddi staff. Nid yw'r ysgol ar agor i blant.
INSET - Staff training day. School is not open to pupils.
Ysgol Gynradd Gymraeg Bronllwyn
Monday 05 January 2026
Diwrnod HMS i`r staff
INSET Day for staff
Tuesday 06 January 2026
HMS Diwrnod 3
INSET Day 3
Ysgol Gynradd Gymraeg Evan James
Friday 22 May 2026
Diwrnod HMS/INSET Day
Ysgol Gynradd Gymraeg Llwyncelyn
Monday 05 January 2026
INSET Day - No school for the children.
Friday 13 February 2026
INSET Day - No school for children
HMS - Dim ysgol i'r plant
Ysgol Gynradd Gymraeg Llyn Y Forwyn
Monday 05 January 2026
School closed for INSET
Ysgol Gynradd Gymraeg Tonyrefail
Monday 05 January 2026
Ysgol ar gau i ddisgyblion / School closed to pupils
Ysgol Gynradd Gymraeg Ynyswen
Ysgol Gynradd Gymunedol Gymraeg Llantrisant