Complex sentence: On rare occasions, the city experiences surprisingly low temperatures for its zone; during late January and early February 2011, a cold wave caused temperatures to drop to 10 ° C, with the lowest being 2 ° C in the morning and noon of 4 February.
Split into simpler sentences: On rare occasions, such as during late January and early February 2011, the city experiences surprisingly low temperatures for its zone. The temperatures were from 10 ° C and the lowest being of 2 ° C in the morning and noon of 4 February.