Paul, April next year could be great! If its anything like this April it could be clear, lots of sunshine and no snow or blizzards like in previous years!
I gave advice to a pilgrim not to walk in early April because there are usually late snows and she could have trouble in the high places (like the Irago Mountains outside of Leon or at O Cebreiro.) But, it was a really hot April and there was no snow.
I also recommend pilgrims walk in September. We had days over over 31oC in September. Go figure! Who can predict the weather these days? England and Wales have just had the hottest 1 October on record.
From the Met Office:
Provisionally, the highest temperature of the day was 29.9 °C, recorded at Gravesend in Kent. This beats the previous record of 29.4 °C recorded at March in Cambridgeshire, which has stood since 1 October 1985. Wales also has a new national record, 28.2 °C was recorded at Hawarden, Flintshire. The previous record was 26.4 °C recorded at Ruthin, Denbighshire, again on 1 October 1985. These new records come at the end of an increasingly hot week across many parts of the UK and we may well see record breaking temperatures in some areas again on Sunday.