Charles Platiau / Reuters
People relax in the sun near the fountains at Trocadero square near the Eiffel tower as unusually warm temperatures hit Paris on Friday.
Alastair Grant / AP
French tourists have a picnic in the park as they sit in the sun in deck chairs in Hyde Park, London, on Friday. Temperatures in the capital are expected to rise to 20 celsius (68 fahrenheit) this weekend, far above the normal average for March.
Michele Tantussi / AFP - Getty Images
People enjoy the sun at the Goerlitzer park on Friday in Berlin as the temperature reached 18 degrees celsius.
Spring is off to a warm start in 2012, but it remains to be seen how this year will compare to 2011. Last year, human activity kept global temperatures close to a record high according to the World Meteorological Organization in this Reuters story:
On average, global temperatures in 2011 were lower than the record level hit the previous year but were still 0.40 degrees Centigrade above the 1961-1990 average and the 11th highest on record, the report said.
WMO Secretary-General Michel Jarraud warned that the consequences of global warming could be permanent. "The world is warming because of human activities and this is resulting in far-reaching and potentially irreversible impact on our Earth, atmosphere and oceans," he said.
La Nina, a natural weather phenomenon linked to heavy rains and flooding in the Asia-Pacific and South America and drought in Africa, was one of the strongest in the past 60 years and stayed active in the tropical Pacific until May 2011.