is it a sin to say something bad about anything in nature for example saying an animal is ugly or saying the weather is annoying etc

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

There is no sin in describing the weather as bad or annoying as a description alone; however, the blameworthy act is to do so as a way of expressing objection, resentment, or dissatisfaction with the decree of Allaah, The Exalted.

The following anecdote is narrated in Siyar A‘laam An-Nubalaa’, “One day a man remarked, ‘How extremely cold it is today!’ So, Al-Mu‘aafa ibn ‘Imraan turned to him and said, ‘Do you feel any warmer now? If you had remained silent, it would have been better for you.’ I - Ath-Thahabi - say, ‘It is permissible to make such a remark; but they (the righteous predecessors) disliked unneeded talk.”

Muhammad ibn Ibraaheem Aal Ash-Shaykh wrote, “There is no harm in describing time as hard, prosperous, good or evil, as Allaah, The Exalted, described time in the following verse (what means): {...which Allaah imposed upon them for seven nights and eight days in gruesome succession...} [Quran 69:7] Allaah, The Exalted, also says (what means): {Then will come after that seven difficult [years] ...} [Quran 12:48]. The Prophet, sallallaahu ‘alayhi wa sallam, said: “No time will come but will be followed by one worse than it.”

Shaykh Sulaymaan Al-Maajid was asked about describing unpleasant weather as “bad weather”. He answered, “There is no sin in that and it is not considered a form of cursing time which is forbidden.”

There is much evidence supporting this.

As for describing an animal as ‘ugly’, it is not a sin. Allaah, The Exalted, described the donkey’s voice as ‘the most unpleasant and disagreeable voice’ in the Quran. Allaah, The Exalted, says (what means): {…Indeed, the most disagreeable of sounds is the voice of donkeys.} [Quran 31:19]

Allaah Knows best.