It's the right rain, but the wrong month

April might have been a washout but the drought actually got worse

Despite flash floods and gale-force winds battering the country, with more expected this weekend, Britain's drought worsened last week – because rain is falling in the wrong months.

The UK remains on course for one of the wettest Aprils on record, with most of the country, with the exception of northern Scotland, today due to see 70mph winds and huge downpours – up to 40mm of rain in places – causing yet more flooding, traffic chaos and power cuts.

Yesterday, the Met Office issued an amber alert – its second-highest warning, meaning "be prepared" – for parts of the West Midlands. And last night, the Environment Agency (EA) warned of the possibility of localised flooding across parts of the South-west, South-east and Midlands, the east of England, and Wales.

Conditions are expected to improve next week, but the deluge will make this month one of the wettest Aprils since reliable records began in 1910.

Some 97mm of rain fell between 1 and 25 April, the Met Office said, the ninth wettest on record. The wettest April was in 2000, when 142.6mm fell. April's average is just 67mm.

The irony that many of the areas at risk of floods – the South-east, East Anglia, the Midlands, the South-west, and South and East Yorkshire – are currently in a state of drought after two unusually dry winters has not been missed.

More puzzling still, the EA said that the drought, the worst since 1921, actually worsened last week because downpours failed to filter deep underground – instead falling on hard, compacted soil caused by prolonged dry weather. It meant that the water ran off overground, causing flooding, while other rainfall has been lost to evaporation, with rising temperatures, and growing plants.

Of the 27 groundwater-measuring sites across England and Wales, 14 were exceptionally low this week – up from 13 last week. An EA spokesman said: "People are now seeing why winter rainfall is so important. "Summer rain can replenish rivers and reservoirs and what we see above ground in the short term. But what it doesn't do is refill the aquifers [underground deposits of water used by water companies]. The vegetation and the increasing temperatures [towards summer] make it less effective. Groundwater only really recovers over winter rainfall."

Mark Wilson, a Met Office forecaster, added: "Although it is a wet month, only three months in the last two years in southern regions have seen significantly higher rainfall than average. We need several months' rain, probably consecutively, to see an effect on ground levels. We really need the rain in the winter months."

Meanwhile, parts of Europe basked in summer temperatures – with the mercury in Innsbruck, Austria, and Vilnius, Lithuania, approaching 30 degrees.

Back home, hosepipe bans imposed by seven water companies across the south of England remain. The EA suggested that householders buy water butts to capture rainfall to use to water gardens if the dry weather returns.

Meanwhile, the birth of a cygnet in Dorset yesterday struck a brighter note at the end of a miserable week. According to folklore, the birth of the first swan at the Abbotsbury Swannery signals the beginning of summer.

John Houston, the swannery's general manager, summed up the national mood. "It's fair to say we're warmly welcoming the first day of summer," he said.