Don't search or ask for "downspout extensions", but just "downspout".
They should have regular downspouts in the same material as the vertical part that's already installed. Just use an elbow and connect to that.

I'm not a big fan of the big orange store, but the link is for reference.

[–] InEnduringGrowStrong@sh.itjust.works 6 points 10 months ago

Also, they exist in different sizes, measure yours to be sure.
It's likely 2"x3" or 3"x4".
"A" elbows are bent with their wide side horizontal.

Whereas B" elbows are bent with their tall side vertical.

Both types are available in different angles: 30, 45, 75, 90.

Get a few short self-tapping metal screws to hold everything in place.

[–] BlackVenom@lemmy.world 4 points 10 months ago

Yes. They also make adapters for 3 and 4" PVC drainage pipe.

[–] Xartle@lemmy.ml 3 points 10 months ago

Yes, just make sure it stays clear, so the more slope the better.

[–] ikidd@lemmy.world 3 points 10 months ago* (last edited 10 months ago)

You can take a piece of downspout, cut a piece out of the top of it to create ears, then screw those ears to an elbow mounted on the bottom of the existing downspout. Then you can fold the extension up when mowing. Bonus points if you make a little hook out of the cutout and screw it to the side of the downspout high enough to latch the extension when it's folded up.

Like this.

Or this