The discrepancies came to light after newspaper photographer Håkan Sjöström, who takes a keen interest in the weather, compared the BBC’s forecasts for his home town of Norrköping with those from SMHI, Svenska Dagbladet reports.
The problems are restricted to weather reports delivered by SMHI to websites belonging to newspapers and local authorities. The data is sent automatically, without being checked by a meteorologist.
What Sjöström found was that online forecasts by SMHI, which has its headquarters in Norrköping, were less accurate than those by the British broadcaster. Sometimes the forecasts would differ by as much as 10 degrees celsius. The BBC gets its data from the British Met Office, owned by the UK Ministry of Defence.
SMHI online reports recently indicated temperatures in Söderköping ten degrees lower than those in neighbouring Norrköping. The BBC’s figures were more accurate.
A spokesman for SMHI, Sten Laurin, said that they hoped to fix the problem through more thorough checks of information used for online forecasts.
Asked how the BBC could have a better idea of the weather in Norrköping than meteorologists in Norrköping itself, he said it was hard to explain.
“I would have thought that it is from us that they get their information. But it might be that they are using our manually checked prognoses,” he said.