1st Major Sign: The Dajjaal
Before Dajjaal appears there will be Three Years of Severe Famine
The Prophet (pbuh) said, "Before Dajjaal appears there will be three difficult years in which the people will suffer severe famine. In the first year, Allah will command the sky to withhold one-third of its rain and the earth to withhold one-third of its produce. In the second year, He will command the sky to withhold two-thirds of its rain and the earth to withhold two-thirds of its produce. In the third year, He will command to withhold all of its produce, and nothing will grow. All cloven-hoofed animals will die, except those that Allah wills." It was said: "What will the people live on at that time?" He said: "Tahlil, Takbir, Tasbih and Tahmid. That will take the place of food for them."
Sunan Ibn Maajah
Vol 5, Hadeeth 4077
Saheeh Muslim
Vol 7, Hadeeth 7393