wttr.in is translated in NUMBER_OF_LANGUAGES languages:

    SUPPORTED_LANGUAGES

Translated/improved/corrected by:
    
    * Afrikaans:    Casper Labuschage @casperl (on github)
    * Armenian:     Aram Bayadyan @aramix, Mikayel Ghazaryan @mkdotam, Grigor Khachatryan @grigortw
    * Azerbaijani:  Dmytro Nikitiuk, Elsevar Abbasov
    * Belarusian:   Igor Chubin, Anton Zhavoronkov @edogby (on github)
    * Bosnian:      Ismar Kunc @ismarkunc
    * Bulgarian:    Vladimir Vitkov @zeridon (on github)
    * Brazilian-PT: Tupã Negreiros @TupaNegreiros (on github)
    * Catalan:      Angel Jarabo @legna29A
    * Croatian:     Siniša Kusić @ku5ic
    * Czech:        Juraj Kakody
    * Danish:       Kim Schulz @kimusan (on github)
    * Dutch:        Youri Claes
    * Frisian:      Anne Douwe Bouma @anned20 (on github)
    * Esperanto:    Igor Chubin
    * Estonian:     Jaan Jänesmäe @janesmae (on github)
    * Finnish:      @Maxifi
    * French:       Igor Chubin, @daftaupe 
    * German:       Igor Chubin, @MAGICC (https://kthx.at)
    * Greek:        Panayotis Vryonis and @Petewg (on github)
    * Hebrew:       E.R.
    * Hungarian:    Mark Petruska
    * Italian:      Diego Maniacco
    * Icelandic:    Óli G. @dvergur, Skúli Arnlaugsson @Arnlaugsson
    * Indonesian:   Andria Arisal @andria009
    * Japanese:     @ryunix
    * Kazakh:       Akku Tutkusheva, Oleg Tropinin
    * Korean:       Jeremy Bae @opt9, Jung Winter @res_tin
    * Latvian:      Gunārs Danovskis
    * Macedonian:   Matej Plavevski @MatejMecka
    * Norwegian:    Fredrik Fjeld @fredrikfjeld
    * Nynorsk:      Kevin Brubeck Unhammer (https://unhammer.org/k/)
    * Persian:      Javad @threadripper_
    * Polish:       Wojtek Łukasiewicz @wojtuch (on github) 
    * Portuguese:   Fernando Bitti Loureiro @fbitti (on github)
    * Romanian:     Gabriel Moruz
    * Russian:      Igor Chubin
    * Spanish:      Fernando Bitti Loureiro @fbitti (on github)
    * Slovak:       Juraj Kakody
    * Slovenian:    B.S.
    * Swedish:      John Eriksson
    * Serbian:      Milan Stevanović @FathVader
    * Swahili:      Joel Mukuthu
    * Turkish:      Atabey Kaygun, Yilmaz @edigu, Volkan Tokmak(@volkanto)
    * Ukrainian:    Igor Chubin, Serhiy @pavse
    * Uzbek:        Shukhrat Mukimov
    * Welsh:        Daniel Thomas
    * Vietnamese:   Lưu Vĩnh Phúc @phuclv90 (on github)

and many many others.

In the not likely case wttr.in is not yet translated in your language 
you can help with the translation.
Please start with one of the following steps:

    * Open a GitHub issue: github.com/chubin/wttr.in
    * Write an email to igor@chub.in
    * Write PM or tweet to igor_chubin