I think it might be Robinia pseudoacacia 'Frisia', whose leaves turn golden yellow as the season advances (before autumn). But I am hesitant because of the strong taper on the trunk. Perhaps the tree has been pruned fairly heavily in the past?
If the trunk and main branches have have stout thorns, I might favour Gleditsia triacanthos,
but that turns yellow only as autumn approaches, and we are not there yet (and I think you would have mentioned the thorns).
Other vague possibilities ruled out:
- Koelreuteria paniculata (that has red rachises)
- Sophora japonica (various)
- Acacia dealbata (various)
- Mimosa spp (various, mostly not hardy enough to have achieved that size)
Any clues about flowers / fruit / scent / thorns / evergreen-ness could be useful...