Volcanic ash from Iceland caused yet more travel disruption today as a number of flights from the UK and Ireland to Spain, Portugal and France were grounded.
An ash cloud forced 15 Spanish airports to close this morning, and they were expected to remain shut until the early evening.
Ryanair said airspace over southern France could also be restricted.
London Stansted Airport saw 25 Ryanair services to destinations including the Canary Islands, Spain and Portugal cancelled, along with four easyJet flights.
At Gatwick, three easyJet services to Portugal were grounded while another four Ryanair flights to Alicante, Madrid and Barcelona were cancelled.
Ryanair put details of cancelled flights on its website including services from East Midlands, Birmingham, Bristol, Leeds and Liverpool.
It advised customers to check their flight status before travelling to the airport.
Another, higher level ash cloud is currently over the Atlantic causing westbound flights to re-route to avoid it.
A spokesman for Heathrow Airport said that transatlantic services suffered delays of 10 to 15 minutes to allow time to fly around the ash cloud.
He said disruption to European services was minimal, with only a small number of flights going to La Coruna affected.
The disruption could continue into next week if northerly winds bring ash over western Scotland and Ireland.
Renewed activity in the Eyjafjallajokull volcano sent ash up to heights of 20,000 to 30,000ft earlier this week, according to the Met Office.
Forecaster Victoria Kettley from MeteoGroup, the weather division of the Press Association, said "We're seeing more of a northerly wind from tomorrow in Scotland and over the rest of the UK on Monday and Tuesday.
"It looks as if Ireland and western Scotland could be affected. The wind is northerly rather than north westerly so it will not bring the ash right across the UK.
"If it was to go north westerly it would bring it across the rest of the UK, but at the moment we're looking at more northerly winds."
On Wednesday, an area of low pressure over Iceland is expected to bring the ash away from the UK and Ireland.
Met Office forecaster Andy Bodenham said that the ash over Spain is moving towards the south of France and is expected to disperse over the next few days.
The ash plume has already caused travel disruption for thousands of passengers over the past three weeks.