Table:
0
A
B
C
D
E
F
G
H
1
Year
2011
2010
2009
2008
2007
2006
2005
2
Highest mean annual temperature
°C () Valentia Observatory
°C () Valentia Observatory
°C () Valentia Observatory
°C () Valentia Observatory
°C () Valentia Observatory
°C () Valentia Observatory and Rosslare
°C () Valentia Observatory
3
Lowest mean annual temperature
°C () Knock Airport
°C () Knock Airport
°C () Knock Airport
°C () Knock Airport
°C () Knock Airport
°C () Knock Airport
°C () Knock Airport
4
Highest temperature
°C () Athy 3 June and Cavan 3 June
°C () Ardfert 23 May
°C () Galway 2 June
°C () Ardtarmon 28 July and Castlederg 28 July
°C () Ballyshannon 9 June
°C () Elphin 19 July
°C () Kildalton 12 July
5
Lowest temperature
°C () Katesbridge 20 January
°C () Castlederg 23 December
°C () Mullingar 25 December
°C () Katesbridge 18 February
°C () Cavan 7 February
°C () Straide 3 March
°C () Casement Aerodrome 3 March
6
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office
Source: Met Éireann / Met Office

Questions and formulas:
Question: What is 2009, when Year is "Highest Mean Annual Temperature"?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:H1,A1="highest mean annual temperature"),4))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:H6,A2:A6="highest mean annual temperature"),4))
Level: medium