Weather experts say ash from the Icelandic volcano - causing problems with flights - has come down in the Thames Valley.
Ash disrupts schools
Some schools in Oxfordshire have had to stay partly closed after the Easter break, because teachers are stuck abroad.
They've been unable to get back because of the flight ban that's been in place as a result of the volcanic ash cloud hovering over Europe.
King Alfred's School in Wantage was closed to years 7 and 8 on Monday 19 April because 16 teachers and eight support staff are stranded abroad. Faringdon Community College was closed to years 7, 8 and 9 because 11 teaching and support staff are missing.
King Alfred's say they've been able to bring in supply teachers which means they were able to open to all children on Tuesday 20 April, except those in year 7 who were given work to do at home. The school was still open to children in year 7 if parents were unable to let them stay at home.
Faringdon Community College say they were able to get in enough agency staff to open to all pupils on Tuesday 20 April.
Sixty of their sixth formers were able to get back to Faringdon on Monday 19 April from a schooltrip to Italy, following a 25 hour coach journey. Their trip included a visit to Pompeii - the Roman town destroyed by an eruption of the volcano Vesuvius.
SCHOOL CLOSURE - King Alfred's School, Wantage
closed to year 7 children on Tuesday 20 April - children were given work to do
The school was open for 'childcare' if parents were unable to let their children stay at home
The school will be closed to year 8 children on Wednesday 21 April
The school will be closed to year 9 on Thursday 22 April
The school will be closed to year 10 on Friday 23 April