Vaisala Corporation ANNOUNCEMENT 11.6.2012 SHARE REPURCHASE 11.6.2012 In the Helsinki Stock Exchange Trade date 11.6.2012 Bourse trade Buy Share VAIAS Amount 550 Shares Total cost 8.297,00 EUR Average price/ share 15,0855 EUR Highest price/ share 15,20 EUR Lowest price/ share 15,02 EUR Vaisala Corporation now holds a total of 158.424 shares including the shares repurchased on 11.6.2012. On behalf of Vaisala Corporation Nordea Bank Finland Plc Petri Simberg Julius Summanen