In the early hours of Tuesday morning, experts at the Pitsford weather station recorded temperatures of –5.5C, the coldest January day on record in Northamptonshire since 2002.

But the weather station's manager, Mike Lewis, said daytime temperatures were also a real cause for concern.

He said: "The temperatures have been extremely low this month. And it's not so much the frosts overnight that are the problem.

"The daytime maximum temperatures are struggling to hit 3C and at this time of year we should be looking at 7C to 8C. So we're currently substantially below the temperatures we should be getting."

The coldest recorded temperature in 2008 was –4.9C on February 17.

But even this week's low of –5.5C is much higher than the lowest temperature ever recorded in Northamptonshire, which was –18.3C on February 8, 1895.

It is also in advance of the lowest temperature ever recorded in England, which was –26.1C at Newport, in Shropshire on January 10, 1982.

Mr Lewis said Northamptonshire would not experience anything like that over the coming week, but he did warn the cold spell was set to continue until into the weekend.

He said: "There's going to be a very slow improvement over the next few days, but it's going to remain cold right through to the weekend, with temperatures likely to fall to –4C again overnight."

The Met Office also warned of a danger of fog in some place tonight.

"Things will change on Sunday though, hopefully it could reach up to 8C, which is a bit more like the temperatures we should be having at this time of year," said Mr Lewis.

Snow and ice caused chaos in Northampton at the start of this week with the accident and emergency department at Northampton General Hospital inundated with people suffering broken wrists and back injuries as a result of slipping over.