。
The Rio Carnival is held in February.
Literal
Rio [genitive-の] carnival [topic-は] February [at-に] is-held.
A factual statement about an international event. リオ and カーニバル are loanwords. 二月に ('in February') uses the time particle に. 開催される (かいさいされる, 'is held / is hosted') is the passive of 開催する — standard for describing scheduled events. A straightforward informational sentence.