Sahih Al Bukhari Hadith Number 1036

Narrated Abu Huraira: The Prophet (peace be upon him) said, “The Hour (Last Day) will not be established until (religious) knowledge will be taken away (by the death of religious learned men), earthquakes will be very frequent, time will pass quickly, afflictions will appear, murders will increase and money will overflow amongst you.” (See Hadith No. 85 Vol 1).

15  Invoking Allah for Rain (Istisqaa)
Hadith number 1036
Volume no 2
Chapter: 27 ( Earthquakes and (other) signs (of the Day of Judgement)