Due to Atmospheric conditions (A weather front making us hotter than Spain) freeview reception is struggling to work in your area.
You will either lose some/all channels or have break up of signal with “No signal” appearing.
This is due to last for the next 2-3 days.
Do not retune your tv as it will not improve the situation
You could alternatively watch catch up services in the meantime if you have them. As these come via the internet rather than through the aerial.
Please share and tell friends/family