Why?

have an outdoor grasscourt tennis championship in England in June?????

years without rain 1931, 1976, 1977, 1993, 1995

Years when play extended into a third week
1919, 1922, 1925, 1927, 1930, 1963, 1972, 1973, 1982, 1988, 1989, 1991, 1992, 1996, 1997, 2000, 2001

June has never been a reliable summer month. "The polar front is responsible for bringing frontal systems and connected unsettled weather to the UK. In June, the ground and oceans are not warm enough to move the polar front reliably north and so allow the Azores high to stretch north over the UK, which would bring fine dry weather. This is why on average the weather in June is not reliably sunny, dry and warm.