After a very cold February, with daily high temperatures in Berlin-Dahlem seldom above 14 degrees Fahrenheit, spring set in early in March. The high-pressure areas "Gulliver" and "Harry" bestowed plenty of sunshine and temperatures up to 68 degrees Fahrenheit on the region. The mild weather lasted nearly two weeks, which is very unusual for the month of March. In very sheltered or sun-exposed areas, birch pollen allergens were released into the air.

On Sunday, March 25, 2012, a birch pollen allergen concentration of 50 per cubic meter of air was measured at the Institute of Meteorology of Freie Universität Berlin. This was the second earliest beginning of the birch pollen season in Berlin since records were begun in 1984. During that period, the only time that the birch pollen season started earlier was in 1990, on March 20.

For information about the current pollen count in Berlin as well as pollen forecast information, provided by the Institute of Meteorology and MeteoGroup Deutschland GmbH, see: www.met.fu-berlin.de/de/polleninfo or call: 09001 270 643 (0.62 € / min). A 2012 pollen calendar is also available on the website.