February was Earth's second-warmest such month on record, finishing up as the second-warmest winter and warmest 12-month period on record, according to preliminary NASA data. Both of these milestones signal the continued influence of manmade global warming as well as natural climate factors that are acting to elevate global temperatures.
The most striking aspect of the February temperature data is the sharp dichotomy between the much colder-than-average Midwest and Eastern U.S., compared to the West, where many cities were flirting with record warm for the month.
In fact, much of the world saw above average temperatures during February, including nearly all of Eurasia, Australia, Africa and much of South America. Some areas, including in Russia, were up to 15 degrees Fahrenheit above average for the month.
Part of the unusual warmth was due to a developing El Niño event in the Pacific Ocean, which is temporarily boosting temperatures in the vicinity of the equator and adding heat to the atmosphere.
The mild February means that the March 2014 to February 2015 period was the hottest 12 months on record, beating February 2014 to January 2015. This metric is considered to be more significant since it ignores arbitrary calendar year limits, and characterizes climate trends over the longer term.
The warmth in the West and Alaska was particularly noteworthy, as the Golden State is in an increasingly dangerous position heading into the 2015 dry season.
California set a record for the warmest winter in state history, beating the old record set just last year. San Francisco had its warmest winter in city history, and for the first time, it did not rain at all in that city during the month of January, which is normally among the city's wettest months.
For a state already mired in a severe drought, this was not the winter season California needed. Several years of drought have depleting the state's reservoirs, as thirsty farmers desperately tap groundwater, causing land in parts of the state to sink.
One prominent water researcher has warned that the state has just about a year's worth of water left.