CHICAGO, Feb. 16 (Xinhua) -- The first 14 days in February were about 11 degrees Celsius above normal, and tied to the second warmest first half of February in Chicago on record, as against the warmest first half of February with an average daily temperature of 5.22 degrees Celsius in 1882.
Chicago recorded an average daily temperature of 3.67 degrees Celsius in the first half of February in 1877, and 2.44 degrees Celsius in 1990, the Chicago Tribune quoted Ricky Castro, a meteorologist at the National Weather Service in Romeoville, as saying on Friday.
Trent Ford, the Illinois state climatologist, attributed the above-average temperatures largely to a "strong" El Niño and long-term warming due to climate change.
This climatological winter, December, January and February together with just a couple weeks of February left, has also been a top five warmest winter season on record in Chicago, Ford said.
If warmer temperatures continue into March, an early start to spring is possible, Ford said.
Occurring on average every two to seven years, El Niño is a natural climate phenomenon where sea surface temperatures are warmer than average in the central and eastern Pacific Ocean near the equator, according to the weather service. El Niños usually begin in the summer and peak in intensity during the winter.
