I think it's appropriate to post this du'aa on this extremely cold and wet day. It was sent in email from Darul Iftaa Mahmudiyyah on the 5th of this month.
The following duaa should be recited on cold days:
لا ِاله ِالا الله ُمَا أشَدَّ بَرْدَ هذا الْيَوْمْ ، اَللّهُمَّ أجِرْنِيْ مِنْ زَمْهَريْرِجَهَنَّمْ.
( رواه ابن السني - 307 - )
Laa ilaaha illallahu ma ashadda barda hazhal yawm , allahumma ajirni min zamhareeri jahannam.
Trans. "There is no deity but Allah, How severe is the cold of today!
O Allah! Protect me from the severe cold of Jahannam"
Rasulullah صل الله عليه و سلم is reported to have said: " When a person recites this supplication, Almighty Allah says to Jahannam : "Verily a servant of mine has sought refuge in me from you, bear testimony that I have granted him salvation from you"
( Ibnu Sunni # 307 )