Hell (Jahannam)
And indeed he (Satan) did lead astray a great multitude of you. Did you not, then, understand? This is Hell which you were promised! Burn therein this Day, for that you used to disbelieve.
The Noble Qur'an 36:62-64
Description of Hell
Hadith - Al-Tirmidhi #5681, Narrated AbuSa'id al-Khudri 
The Prophet 
said, "The awnings of Hell have four thick walls, each wall a distance of forty years." [Tirmidhi transmitted it]
The Noble Qur'an Hud 11:106
As for those who are wretched, they will be in the Fire, sighing in a high and low tone.
Hadith - Al-Muwatta 57.2
Malik related to me from his paternal uncle Abu Suhayl ibn Malik from his father that Abu Hurayra said, "Do you think that it (hell) is red like this fire of yours? It is blacker than tar."
Hadith - Qudsi 38
When Allah (swt) created Paradise and Hell-fire, He sent Gabriel to Paradise, saying: Look at it and at what I have prepared therein for its inhabitants. The Prophet said: So he came to it and looked at it and at what Allah had prepared therein for its inhabitants. The Prophet said: So he returned to Him and said: By your glory, no one hears of it without entering it. So He ordered that it be encompassed by forms of hardship, and He said: Return to it and look at what I have prepared therein for its inhabitants. The Prophet said:
So he returned to it and found that it was encompassed by forms of hardship. Then he returned to Him and said: By Your glory, I fear that no one will enter it. He said: Go to Hell-fire and look at it and what I have prepared therein for its inhabitants, and he fount that it was in layers, one above the other. Then he returned to Him and said: By Your glory, no one who hears of it will enter it. So He ordered that it be encompassed by lusts. Then He said: Return to it. And he returned to it and said: By Your glory, I am frightened that no one will escape from entering it.
Hadith - Sahih Bukhari 4:464, Narrated 'Abdullah bin Abbas , see also Bukhari 4:464, 7:124
"...Then I saw the (Hell) Fire, and I have never before, seen such a horrible sight as that, and I saw that the majority of its dwellers were women." The people asked, "O Allah's Apostle! What is the reason for that?" He replied, "Because of their ungratefulness." It was said. "Do they disbelieve in Allah (are they ungrateful to Allah)?" He replied, "They are not thankful to their husbands and are ungrateful for the favors done to them. Even if you do good to one of them all your life, when she seems some harshness from you, she will say, "I have never seen any good from you.' "
Hadith - Reported by Darimi, Narrated Abu Sa'id , Tirmidhi transmitted something similar but he said seventy instead of ninety-nine.
Allah's Messenger said: There dominate ninety-nine dragons over the unbeliever in the grave. They (constantly) bite him and sting him till there comes the hour (of resurrection). (These dragons are so poisonous) that if one of them exhales on the Earth, no verdure will ever grow upon it.
Hadith - Al-Tirmidhi, Narrated Abu Hurayrah Transmitted by Tirmidhi
The Prophet was asked about the things which would enable most people to enter Paradise. He answered: Being careful about one's obligations to Allah, and good behaviour. Thereafter, he was asked: What are those things which will lead a person into Hell? He answered: His mouth and genitals.
Hadith - Bukhari 8.485, Narrated Abu Huraira
The Prophet said, "A slave (of Allah) may utter a word which pleases Allah without giving it much importance, and because of that Allah will raise him to degrees (of reward): a slave (of Allah) may utter a word (carelessly) which displeases Allah without thinking of its gravity and because of that he will be thrown into the Hell-Fire."
Hell Affects the Seasons
Hadith - Bukhari, Narrated Abu Huraira
The Prophet said,
"In very hot weather delay the Zuhr prayer till it becomes (a bit) cooler because the severity of heat is from the raging of the Hell-fire. The Hell-fire of Hell complained to its Lord saying: O Lord! My parts are eating (destroying) one another. So Allah allowed it to take two breaths, one in the winter and the other in the summer. The breath in the summer is at the time when you feel the severest heat and the breath in the winter is at the time when you feel the severest cold."