They call it sporadic E or Es yet it is surprising how often my 500mW WSPR beacon on 10m is copied in Italy very early in the mornings, often before breakfast. Whatever triggers the Es must be just right for this path early in the morning. Often Scandinavians and more northern stations are more common later in the Es season and in the evenings.
UPDATE 0708z: Now DK7UG is spotting my 10m WSPR beacon strongly. No signs here of Es on 6m WSPR.
UPDATE 0906z: One Italian spot by Es on 6m WSPR so far - IU1DZZ (973km) at 0748z.
UPDATE 1132z: EA1KV (1304km) spotting me on 10m WSPR but only Nick G0OQK (98km) being copied on 6m WSPR.
UPDATE 1205z: EA1KV and I are exchanging spots on 6m WSPR and CN8LI (2113km) just spotted on 6m WSPR.