On 2 servers with real players, out of 8 Steam servers that run it now, fakes and empty ones included. Checked 03:56 UTC.
cs_skybox is a community hostage rescue map. It is not one of the maps that come with the game, so servers send it to players from the Workshop when they join.
Over the last 30 days cs_skybox was the #134 map on CS2 community servers, with 39 real players on it at any moment on average - 0% of everyone playing. It ran on about 7 servers with real players at a time. Right now 5 people play it on 2 servers, most of them on servers in Russia. It is busiest on Thursday around 18:00 UTC and quietest on Wednesday around 22:00 UTC.
Right now 5, on 2 servers from the Steam server list. Over the last 30 days it had 39 real players on average at any moment. Fake servers and bots are not counted, and Valve matchmaking is not in the list.
On Thursday around 18:00 UTC. The grid above shows every hour of the week in your own time zone.
The busiest right now: CS2 SKIN INSPECT #8 [RU] — CYBERSHOKE.NET (4 players), CS2 SKIN INSPECT #9 [RU] — CYBERSHOKE.NET (1 players), CS2 SKIN INSPECT #3 [RU] — CYBERSHOKE.NET (0 players). The full list is under "Servers running it now", and every server has its own page with its history.
de_mirage43,270 players on average
de_dust217,902 players on average
sandstone_fb14,444 players on average
de_mirage_fps6,337 players on average
awp_lego_25,419 players on average
awp_lego_2_fb4,842 players on average
de_mirage_christmas2,843 players on average
<null>1,271 players on average
bhop_emevaelx31,055 players on average
duels_mirage_1x11,013 players on average
de_inferno905 players on average
de_nuke775 players on average
RU