Vaisala - Changes in company's own shares

SHARE REPURCHASE 28.5.2012

Vaisala Corporation        ANNOUNCEMENT       28.5.2012
SHARE REPURCHASE  28.5.2012                            
In the Helsinki Stock Exchange                         
Trade date                        28.5.2012            
Bourse trade               Buy                         
Share                      VAIAS                       
Amount                                  730  Shares    
Total cost                        11.048,30  EUR       
Average price/ share                15,1347  EUR       
Highest price/ share                  15,16  EUR       
Lowest price/ share                   15,11  EUR       
Vaisala Corporation now holds a total of 148.529 shares
including the shares repurchased on 28.5.2012.         
On behalf of Vaisala Corporation                       
Nordea Bank Finland Plc                                
Petri Simberg              Julius Summanen