There are images from EOSDIS which show cloud cover at around 11:35 UTC but this is obviously not ideal. There may be other sources with a better time match.
https://earthdata.nasa.gov/labs/worl...5742,53.334961
This image was captured at approx 11:35 to the left of the central line and approx 9:55 UTC to the right.
As I said about 50 pages ago there were thunderstorms just to the South of MH17's path and along the path there was fairly consistent high cloud cover (up to around FL320).