Does cold weather sometimes feel worse than it is?
The UK is going through a cold snap, but how can winter days with the same temperature feel different, asks Rachel Argyle.
While 2014 was the warmest year on record, the UK is now in the midst of the longest cold spell in the UK for two years.
The country is experiencing a "blocking pattern", according to Andrew Charlton-Perez, associate professor of meteorology at Reading University, home to one of the largest departments in the world.
"The current cold is associated with a weather feature called a Greenland block. Over the past week, a ridge of high pressure has formed over the Atlantic Ocean and Greenland," he explains.
So why has the past week felt especially bitter? And do people feel better on cold sunny days than they do on overcast, wet but slightly warmer days?
"One thing that makes blocking patterns like this so interesting is that they are relatively persistent, giving rise to perhaps a week of very similar conditions, which is different to the normal, more changeable conditions we usually get in the UK," says Charlton-Perez.
This can change our perception of the weather, he argues. "If we are in a block with similar weather day after day, it feels repetitive. It might feel more like an unusual weather event than a season that is dominated by a sequence of depressions crossing the UK, like last winter."
This current cold snap is being caused by northerly winds, says Mark Wilson, meteorologist for the Met Office. "Some cold days can feel pleasant when there is sunshine and light wind. Conversely, when it is cloudy with precipitation and winds are strong, it can feel very cold. This wind chill is what we have had and will continue to see in the UK in the coming days."
But what exactly is the wind chill factor and why does it make such a difference to the way we feel, both psychologically and physiologically?
"The idea of wind chill indicates how cold it feels on the skin's surface as opposed to the actual temperature," explains Steve Cleaton, forecaster for BBC Weather. "Wind chill relates to a combination of three things - wind speed, moisture content or humidity and the air temperature. Conditions feel coldest on your skin when they are particularly windy and dry. This is because the moisture on our skin evaporates readily in dry air compared to moist air, causing evaporative cooling on the surface of the body. Our bodies work harder to maintain its core temperature, leading us to feel colder."
Wind chill research dates back to American explorers Paul Siple and Charles Passel, who left bottles of water hanging outside their base station in the Antarctic in 1940. They measured how long it took the water to freeze under various wind conditions. But it wasn't until the 1970s that people started using the term "feels like temperature" to describe the wind chill factor.
The complexities of our relationship with cold weather go back to the 19th Century, before forecasting was developed.
"Historically, people relied on weather wisdom - sayings such as 'clouds like rocks and towers, great showers' - to predict weather patterns," says historical writer Peter Moore, author of My Weather Experiment.
"For cold spells there was no way of knowing when they were going to end. For most people, whatever was going on outside - rain, snow, wind, sunshine, rainbows - was simply providential. So when the weather diverted from its usual patterns, as it did during the Year Without a Summer in 1816, people often treated it as an omen or a punishment."
Psychologist Annika Howells shares her time between the UK and Australia and is no stranger to weather extremes.
"Good weather seems to have a real and measurable positive impact on mood, but only up to a point," she comments. "Studies show that spending time outside for 30 minutes a day, not only in higher temperatures, but on cold but clear days, enhances our mood somewhat.
"This can be attributed to a number of factors, including fresh air and open space. However, our mood is not as dependent on 'good' weather as many people seem to believe and much of it comes down to personality and our personal weather preferences. Hotter doesn't necessarily equate to happier either."
The latest news on the cold spell from the BBC
- Snow causes travel difficulties in North East Scotland (2 February)
- Fresh snow brings travel disruption in England (30 January)
- Latest weather updates from the BBC
Speaking from his home in Loch Lomond amid heavy snow, psychologist Prof Alexander Gardner says age is a big factor in perception of cold weather.
"There is a general rubric that how we feel about the weather is defined by our age. Young people in snowy conditions tend to look forward to going out sledging, while if you are old you tend to worry about falling or are concerned about how to stay warm efficiently.
"It is much easier to motivate ourselves to wrap up warm and head outside on a cold but bright day than it is on a gloomy, miserable day."
Gardner believes that negative or positive ions in the air can explain a clear connection between weather and mood. But the nature of the effect of ions is contested.
One woman who knows all about braving the elements is Shona Thomson. As well as being from Scotland, she has gone on to be one of only 16 women worldwide to have run marathons on all seven continents, as well as the North Pole.
"Temperatures there and in the Antarctic dropped to below -30C during the day and -40C at night," she recalls. "Regulating your body is the hardest part. Your body works twice as hard trying to keep warm in polar conditions, in much the same way that our bodies exert more energy on colder days than warmer days in general."
As a runner, Shona believes there can be a difference between types of cold days and its effect on motivation and mood.
"I think the wind chill can really impact performance both mentally and physically. That bitter, raw and biting cold is very unforgiving. Those days tend to be dull and grey too, so it is less appealing to go out.
"The cold, frosty mornings are the incredible runs," she enthuses. "It's hard not to feel alive and invigorated when running on a crisp, winter morning with bright blue skies."
More from the Magazine
Weather forecasters in the UK are warning that it will feel far colder than the actual temperature. It's the wind chill factor. But what does the term mean?
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