OK I think this is the final list of all the (non-manual) stations that matched or broke the old record. I make it 42.
Coningsby 40.3C
Waddington 40.3C
Heathrow 40.2C
St James's Park 40.2C
Gringley on the Hill 40.1C
Kew Gardens 40.1C
Cranwell 40.0C
Northolt 40.0C
Cambridge NIAB 39.9C
Charlwood 39.9C
Cranwell 39.9C
Scampton 39.9C
Wittering 39.9C
Bramham 39.8C
Monks Wood 39.8C
Nottingham WC 39.8C
Battersea Heliport 39.6C
Teddington Bushy Park 39.6C
Topcliffe 39.6C
Woburn 39.6C
Bedford 39.5C
Normanby Hall 39.5C
Sheffield 39.4C
Sutton Bonington 39.4C
Wisley 39.3C
Chertsey Abbey Mead 39.2C
Marham 39.2C
Holbeach 39.1C
Ryhill 39.1C
Writtle 39.1C
Mildenhall 39.0C (h)
Santon Downham 39.0C
High Beach 38.9C
Wellesbourne 38.9C
Coleshill 38.8C
Iver Waterworks 38.8C
Leeming 38.8C
Benson 38.7C
Church Lawford 38.7C
Coventry 38.7C
Houghton Hall 38.7C
Stowe 38.7C
There are also two airports that recorded 40C METARs (the 39C METARs could have been below 38.7)
Humberside 40C (r)
Doncaster 40C (r)
Originally Posted by: Rob K