Vaisala Oyj Stock Exchange Release May 3, 2010 at 3:00 p.m. Vaisala publishes its Q1/2010 results on Tuesday, May 11, 2010 at 8:30 a.m. The stock exchange release will be available on the company website at www.vaisala.com. CEO's presentation will be published at 12.00 noon (GMT +3) on the same day athttp://www.vaisala.com/investors. Briefing Briefing for analysts and media will be arranged in Hotel Kämp, Akseli Gallen-Kallela meeting room, Pohjoisesplanadi 29, starting at 12.00 noon. Please register to the briefing by email tohelena.marjaranta@vaisala.com <mailto:helena.marjaranta@vaisala.com>. Audiocast A live audiocast of the presentation of Kjell Forsén, President and CEO of Vaisala, will be sent starting at 12.00 am (GMT +3). The audiocast will be available athttp://www.vaisala.com/investors. It will be recorded and published at the same address at 2.00 p.m. (GMT +3) on the same day. More information: Helena Marjaranta, SVP Communications, tel. +358 40 5819 102 [HUG#1411147]