On the warmest, sunniest spring Sundays, some 250, 000 people will enter the park, according to the conservancy.

WSJ: Trash Talk in New York City's Central Park

It is also one of the sunniest cities in the United States, ranking in the top 10 for clear days.

BBC: Living in: San Diego

It was a sunny month across all of the UK with sunshine amounts generally close to 150% of normal, making it the sunniest April in the series from 1929.

BBC: Weather - UK Review - April 2011