Fen Blow
For our final article on our favourite weather phenomena, we will be looking into an incredibly rare phenomenon that only impacts a certain area of the UK, a Fen Blow!
The Fens, located in the East of England inland from the Wash, are an area of very low-lying reclaimed marshland. Being in the driest part of the UK along with its very nutrient rich soils, the area is ideal for arable agriculture, and the Fens are used extensively for that purpose. At least a fifth of England’s sugar beet, a fifth of England’s potatoes and a third of England’s fresh vegetables are grown there annually [1].
A Fen blow is a very specific phenomenon local to this area. It occurs when strong winds, unhindered by the flat land, whip up dry and loose topsoil from the agricultural fields to produce a dust storm which can travel for miles. They are most common during Autumn or Spring when soils are bare, dry and often disturbed by heavy machinery. This is exacerbated during periods of prolonged drought, high temperatures, and high wind speeds [2]. This dust storm is made of fine soil particles and depending on its thickness, it can look like a thick black fog. During a Fen blow, our very own Jim Bacon said it was the only time he reported a present weather code of between 30-35 (sand or dust storms)! Being relatively rare, the most recent widespread Fen blow occurred back in 2013.
There are many different environmental and social impacts to this phenomenon. The winds remove the valuable nutrient rich topsoil for the crops, exposing them and potentially damaging them, lowering yield. This soil is also dumped in drifts along roads and into the dykes that criss-cross the landscape, potentially filling them up to 6ft deep and blocking the vital drainage [3]! The soil being blown across roads also greatly reduces visibility, potentially leading to road accidents and travel disruption [4]. This is also a problem for air pollution, causing breathing difficulties and potentially other health issues if not wearing a mask. The soil can also get inside people’s homes, coating everything in a fine silt like powder, worsening this pollution problem and causing more disruption to people’s lives [2].
There are different ways in which locals can reduce the effects of a fen blow, such as keeping the topsoil moist by watering it, planting cover crops and windbreaks, and reducing the overall amount of bare soil. This helps keep the soil where it should be, even when the winds do pick up [2].
We hope you have enjoyed our article series on our favourite weather phenomena, and that our love for weather and the intricacies behind it has inspired you to consider and explore your own favourite weather!
[1] NFU (2019). Delivering for Britain: Food and farming in the Fens. Available at: https://www.nfuonline.com/media/uvhhtjio/delivering-for-britain-food-and-farming-in-the-fens.pdf (accessed: 12/05/2026)
[2] The Fens App (no date). Fen Blow. Available at: https://thefensapp.co.uk/air/fen-blow/ (accessed:12/05/2026)
[3] Paul Simons (2013). Weather Eye: a fen blow. Available at: https://www.thetimes.com/travel/advice/weather-eye-a-fen-blow-kzm7mjrrc30 (accessed: 12/05/2026)
[4] BBC News (2013). Feb Blow phenomenon: Farmers concerned as winds threaten. Available at: https://www.bbc.co.uk/news/uk-england-22463450 (accessed: 12/05/2026)
