I have this white linen bomber and I love it.

https://evereve.com/products/linen-bomber-chalk?variant=44150048784549

Liamolly wraps. Soft as cashmere, washable, beautiful designs in limited edition designs and colors. I have several, every person who touches them wants one.

I have one of these in twill and a similar one by Michael Stars in linen - Anthropologie doesn’t seem to sell it anymore but I’m sure you could find something similar at Evereve.

https://factory.jcrew.com/p/womens/categories/clothing/jackets/jackets/CG369?display=all&fit=Classic&colorProductCode=CG369&colorCode=GR6909&color_name=antique-navy

I dress like you and wear a lightweight cashmere crewneck for this purpose. (Mine are navy, gray, and black.) I wear the sweater over my shoulders when I need just a little warmth.

Love this cardigan: https://www.marinelayer.com/collections/gals-sweaters/products/anacapa-cardigan-2?variant=41928356855882

I have recently seen lightweight jean looking jackets from L’Agencie and Paige at Bloomingdale’s. Also I will wear a button up shirt as a jacket (try Rails), or a thin cashmere sweater (Tuckernuck has a cropped one I like).

I recently bought this lightweight jacket from Evereve. The material is soft and stretchy and it's a nice summer weight, and it's slightly cropped so I'm able to wear it with higher rise pants/shorts or a dress without looking dowdy. Check out their jackets/blazer sections, you might find something there. Or maybe a "lady jacket" type sweater made of 100% cotton--those are all over the place.

Here's the jacket:
https://evereve.com/collections/blazers-jackets

What about an un-buttoned long sleeve linen shirt?

I like your idea of a linen "jean" jacket for the style you described. Blazer seems just a little formal and zip up hoodie seems just a little casual.

Pullover sweater or zip up sweater might work.

Cropped zip up hoodie or track jacket?

Linen blazer or duster

White cotton sweater

I don’t wouldnt say I am preppy, I’d say I’m more “generic” in my dress - e.g., white jeans/shorts and a navy tshirt, or olive pants/shorts and a black tshirt, etc.

Seersucker and blazers are not my vibe, especially for casual wear. But thanks for the idea, and I understand why you suggested it based on my description.

- OP

You sound preppy.. What about a lightweight seersucker blazer?

I’m looking to buy an outer layer (jacket? sweater?) for summer weather, to wear when in summer climates where it gets cooler at night or to wear in DC summers in air conditioning.

My style is “americana classic” - lots of white jeans/shorts and navy/blue tops, sometimes black shorts and white tops.

I used to wear a jean jacket for this purpose, but I’ve fallen out of like with the stiffness of jeans jackets and sometimes a jean jacket was too heavy.

Any ideas of what I should look for? A linen “jean” jacket? Navy cardigan? Links to any suggestions would be great. I’ll shop anywhere, but tend to buy most clothes at stores like J Crew, Anthro, Banana Republic/Gap, Nordstrom.

Thanks.