You have to choose departure destinations
The cheapest month to fly to Cologne is July costing on average 128 £ or October costing on average 129 £.
The most expensive months are March costing on average 176 £ and August costing on average 166 £
The cheapest month to fly to Cologne is Monday costing on average 60 £ or Tuesday costing on average 66 £.
The most expensive days are Friday costing on average 104 £ and Thursday costing on average 85 £.