Freeview has issued a warning to viewers across the UK, as a strong area of high pressure could affect TV signals.
The alert is valid through until the end of Tuesday 19th July. TV reception could become unstable virtually anywhere in the UK.
Freeview is advising viewers not to retune, as reception will be restored when the weather changes. Retuning now will only result in having to retune again when signals are back to normal.
Why is this a problem?
The BBC explains that the issues are caused by the re-use of the same frequencies for TV services by various transmitters.
It advises that “there will be occasions when certain weather conditions allow the signals carrying television services to travel further than expected. Therefore at these times, you can then receive different television services that are using the same frequency. Normally, the signals from each transmitter can only be received by those homes that have aerials with a direct line-of-sight to the transmitter. Being able to receive more than one signal using the same frequency can cause problems such as pixelation.”
In recent years, the number of frequencies available for use by broadcasters has been reduced. Many former terrestrial TV frequencies are now used by 4G and 5G mobile services. At the end of this month, another TV frequency will be discontinued in favour of 5G.
As a consequence, the remaining frequencies have to be more intensely used. This leads to an increased chance of interference during times of high pressure weather conditions. TV aerial installers in the south of England frequently report interference from French services during high pressure weather conditions. That’s despite the addition of extra relays in the past decade along or close to the south and east coast. Relatively new relays include Ashford (Kent), Clacton (Suffolk) and Rouncefall (Essex).
This week’s heatwave is expected to peak on Tuesday, with temperatures reaching nearly 40°C across a wide slice of Southern, Eastern and Central England. Across Northern England and Wales, temperatures will reach well into the 30s.