I am a soup addict all year round and prefer light soups for these seasons.
If you have, or make chicken stock or vegetable stock then use that as a base and add a little cream for;
1.Cream of celery,
2. " " asparagus
3. " " Fennel.
Saute some sliced onion along with the chopped celery/ asparagus / fennel, season and then Blitz. Add cream just before serving. Also a garnish of blue cheese and croutons is good with any of the above. they are very nice served chilled as well.
Carrot and coriander, cauliflower and sage, beetroot and orange,. Garden pea with mint. Same method as above but cream is unnecessary.
As you can see, these are vegetable soups but prawn bisque is wonderful and light if you like shellfish. Hope this helps.