Is it haram to get angry during Ramadan?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The ruling on anger varies according to its motive, so anger for the Sake of Allah is not like anger for one’s own sake, and this is not the same as anger that stems from falsehood: each one of them has a its own ruling. Therefore, the scholars said that there is praiseworthy anger, and dispraised (blameworthy) anger.

The Fiqh Encyclopedia reads: “Anger depends on the reasons that incited it, so it may be praised or dispraised.”

Therefore, the praised anger is what was for the truth and religion, and defending what is sacred; hence, anger in these situations is praiseworthy, and its [i.e. the praiseworthy anger] weakness [in this case] yields to not feeling jealous about what Allah has made sacred, and being satisfied with humiliation and leaving evils to spread and increase. Aa’ishah narrated: “The Prophet never took revenge over anybody for his own sake but (he did) only when the limits of Allah were violated; in which case, he would take revenge for Allah's sake.” [Al-Bukhari]

What is dispraised (blameworthy) is what was for the sake of falsehood, and this is incited by arrogance, and self-conceit, and haughtiness, and this type of anger is Islamically blameworthy.... But if the anger was for one’s own self due to being dealt unjustly by someone or wronged by anyone, then it is better for him to suppress his anger, and pardon those who wronged him or offended him.” [End of quote – Abridged]

It is prescribed for a fasting person who is angry because he was offended by people to say what is mentioned in the authentic Hadeeth: “When any one of you gets up in the morning in the state of fasting, he should neither use obscene language nor do any act of ignorance. And if anyone slanders him or quarrels with him, he should say: “I am fasting, I am fasting.” [Al-Bukhari and Muslim]

In his book Az-Zawaajir, Ibn Hajar Al-Haytami considered anger incited by falsehood as one of the grave major sins, and he compared it with envy and hatred.

For more benefit on how to avoid anger, please refer to Fatwa 86681.

Allah knows best.