I learned these terms during my schooling in the band schools of the LLRIB. They are a bit different from the southern dialects because the seasons move along differently down south. This is how it was explained to us by our Cree teacher, I believe it may have been Mary Cook (In Memorium, opens new window).
January – opāwāhcikanasīs
February – kisīpīsim
March – mikisiwipīsim
April – niskipīsim
May – athīkipīsim
June – opiniyāwīwipīsim
July – opaskowipīsim
August – ohpahowipīsim
September – nimitahamowipīsim
October – pimahamowipīsim
November – kaskatinowipīsim
December – thithikopīwipīsim
The meanings of the months, can be found in the sources below:
Cree Literacy Network – https://creeliteracy.org/2019/09/05/2020-calendar-solomon-ratt-y-and-th-dialects/
LLRIB LearnCree – http://learncree.ca/yearly-calendar