Okay, this is the playlist I went for. I can still add to it of course. Not all suggestions made it on but many did. For those that I didn't choose I either don't like them or they didn't feel summery enough. My choices, just opinion.
Earth, Wind and Fire : September
Jackson 5 : I Want You Back
Stevie Wonder : Signed, Sealed, Delivered
Jess Clynne : Hold My Hand
Wham : Club Tropicana
Aliotta Haynes Jeremiah : Lake Shore Drive
Justin Timberlake : Can't Stop the Feeling
The Lovin Spoonful : Summer in the City
Don Henley : The Boys of Summer
Wham : Young Guns
Mark Robson : Uptown Funk
The Jackson's : Blame it on the Boogie
Beach Boys : Surfin USA
Isley Brothers : Summer Breeze
Earth, Wind and Fire : Boogie Wonderland
Village People : YMCA
Tavares : Heaven Must Be Missing an Angel
The Beatles : Here Comes the Sun
The Beatles : Good Day Sunshine
ELO : Mr Blue Sky
Bob Dylan : Mr Tambourine Man
Donovan : Sunshine Superman
Thanks everyone
Earth, Wind and Fire : September
Jackson 5 : I Want You Back
Stevie Wonder : Signed, Sealed, Delivered
Jess Clynne : Hold My Hand
Wham : Club Tropicana
Aliotta Haynes Jeremiah : Lake Shore Drive
Justin Timberlake : Can't Stop the Feeling
The Lovin Spoonful : Summer in the City
Don Henley : The Boys of Summer
Wham : Young Guns
Mark Robson : Uptown Funk
The Jackson's : Blame it on the Boogie
Beach Boys : Surfin USA
Isley Brothers : Summer Breeze
Earth, Wind and Fire : Boogie Wonderland
Village People : YMCA
Tavares : Heaven Must Be Missing an Angel
The Beatles : Here Comes the Sun
The Beatles : Good Day Sunshine
ELO : Mr Blue Sky
Bob Dylan : Mr Tambourine Man
Donovan : Sunshine Superman
Thanks everyone