This is actually pretty good, however I got the tile right above yours, and I have one complaint - at the very edge (top) of your tile you left a row of pixels that were slightly darker than the rest of the sky. As a result, it was impossible to make a perfect blend. If I blended to that row, it looked like I was careless enough to start with a different color than the sky, on the other hand, I blended to the sky itself, then the line showed up. In the future please try to avoid that. :)

looks good. ;)