After accusations that the national weather service deliberately tinkered with temperature forecasts, a senior meteorologist took the unusual step of apologising on television on Wednesday.

Thomas Bucheli said he and his team were “extremely sorry” for the inaccurately high temperature measurements reported for some southern European locations over the past weeks.

However, he “vehemently rejected” allegations by some media and political circles that the temperatures had been deliberately inflated in an effort to spur climate change debates.

Conservative weekly magazine Weltwoche was the first to notice that temperatures on the SRF weather app and website for southern destinations abroad were often too high – even by up to 8°C.

According to Bucheli, forecasts for non-Swiss destinations are calculated automatically by a “complicated” algorithm. In recent weeks, a heat wave in the Mediterranean region prompted this algorithm to show temperatures – particularly in coastal areas – higher than they actually were.

Bucheli said he and his team are working “flat-out” to correct the errors.

The manually-checked forecasts were only broadcasted through radio. TV weather broadcasts were not affected, Bucheli added. Although the app and website were noted to have been affected by the algorithm, Swiss weather temperatures online and in the app were not affected.