There are really only two-three safe sites (That I know of) to download mods from with full confidence. Unknown sites like that one are frequently reupload sites, which do not have the permission, knowledge, or approval of the mod creator to have them available for download, and most of the time have nothing to do with the actual creator of the mod.
(That site potentially COULD have stuffed malware in alongside the mod, but plenty of those sites just rely on what is essentially stolen ad revenue, instead of using Malware. it is still FAR better to download from trusted sites rather than hoping things don't go badly.)
Those two sites i recommend are Curseforge, and the official minecraft forums (I personally recommend curseforge, it is easier to find things/has stats available for you to see other people have downloaded it)
Incidentally here is the link to the page of the mod you are trying to download
Heat And Climate - Mods - Minecraft - CurseForge
There is not really a simple way to check what you are downloading as far as i am aware, you instead have to rely on the site you are downloading from policing what they have available.
You might find other sites that you find trustworthy, but Curseforge is the primary and most widely known mod site.
(Planetminecraft itself DOES have a mod section, but i haven't actually visited them to be able to tell you about it)
I am fairly confident that those are safe for download as well.
