Since I didn't get my weather records in until after the April 2006 Summaries thread was closed for some reason, here's the April 2006 Summary.
Mean Max 12.2C
Mean Min 4.3C
Mean Temp 8.3C
Highest max: 16.7C (25th)
Lowest max: 6.9C (4th)
Highest min: 9.5C (25th)
Lowest min: -1.8C (5th)
Air frosts: 3
There was sleet/snow on 3 days (sleet on the 7th and 9th, snow on the 8th) and four days with hail or graupel. Snow was lying at around 3pm on the 8th April, but there was nothing on the ground by 0900 the next morning.
Overall the month had a rather cold first third with sunshine and wintry showers, then the remaining two-thirds were dry, consistently warm and notably sunny. There was a remarkably homogeneous nature about the warmth, with no maximum above 17C for the first time in April since 2001.
The average maximum temperature was actually higher than for April 2005, but the average mean and minimum temperature were both the lowest since 2001. It was also the driest April (along with 2002) since 1997.