‘Sunniest April’ completes stark turnaround since recent floods28 April 2020
Although it is raining for many of us this week, sunshine records and a remarkably low rainfall total are both anticipated for parts of the UK this month, just weeks after record-breaking rainfall caused severe flooding.
The University of Reading’s weather observatory has recorded its highest ever monthly sunshine hours total for April. Up to sunset on Sunday, the total had reached 240 hours of sunshine and counting – the highest since the University began recording this in 1956, and surpassing its 1984 record of 234 hours with several days to go.
Despite this week’s showers, there has also been very low rainfall so far this month, putting the UK on course for one of its driest Aprils on record. This follows the wettest February ever recorded earlier this year, when large parts of northern England and Wales experienced heavy flooding.
"This rain is welcome but it will need to rain a lot more and for a lot longer to fill up the soil and groundwater stores in the parts of the country where they are low" - Professor Hannah Cloke, University of Reading
Stephen Burt, Visiting Research Fellow in the Department of Meteorology at the University of Reading, said: “April is often the driest month of the year, but this April’s dryness appears stark after such a wet period during February and March.
“There have been drier years in the UK’s history, and we do expect some rain this week, but nevertheless the UK has only had around a fifth of the rainfall we expect to get in an average April.”
Professor Hannah Cloke, a hydrologist at the University of Reading, said: “We’re not in a drought yet, but the last few months have highlighted the vulnerability of the UK to extremes in rainfall. This rain is welcome but it will need to rain a lot more and for a lot longer to fill up the soil and groundwater stores in the parts of the country where they are low.
“Drought conditions raise the risk of wildfires and can threaten water supplies to our homes in severe cases. They can also increase the risk of flash floods, as soil becomes hard and impermeable, causing heavy rainfall to run off into other areas.
“These wet and dry extremes are costly, and are expected to become more common under climate change. We can expect to see more record-breaking dry and wet months ahead.”
Following the heavy rainfall in February, by the end of March groundwater levels, river flows and reservoir levels were all generally healthy. However, the Water Resources Portal, run by the UK Centre for Ecology and Hydrology, shows that river levels in the north-west of the UK have fallen dramatically this month.
The portal shows rivers in Cumbria have dropped from Exceptionally High to Notably Low in less than two months.
Many rivers in the south remain high, sustained by the high groundwater levels following the winter.
Professor Lindsey McEwen, Director of the Centre for Water, Communities and Resilience at the University of the West of England Bristol, said: “During lockdown people are spending more time outside if they have gardens. They may be well notice increasing dryness and the need to water their plants.
“With working on allotments being an approved exercise, growers are also likely to see early signs of low soil moisture with cracked soils. In the DRY (Drought Risk and You) project, we have been working with the National Allotment Association to prepare advice leaflets on different aspects of water efficiency for gardeners and growers.
“Now is likely to be a really good time learn about how to save and store water when growing, about drought-resistant plants and vegetables and how to make growing resilient to prolonged dry periods.”
The University of Reading is leading research into predicting droughts as part of the About Drought, part of the £12m UK Drought and Water Scarcity project.