Vaisala Oyj Stock Exchange Announcement 14.04.2010 at 12.00 1(1) Vaisala Oyj's 400 unlisted shares (series K) have been converted into listed shares (series A). The conversion has been registered in the Finnish Trade Register April 14, 2010. Listing of the new series A shares has been applied for as of April 15, 2010. Further information: Jouni Lintunen, CFO +358 9 8949 2215 or +358 40 5790181 Vaisala Oyj Distribution: Helsinki Exchanges [HUG#1403427]