According to CAT.POL.H.105 - General:

When showing compliance, the operator must ensure that the mass of the helicopter never exceeds any limits at any stage, including in-flight re-planning and account shall be taken of the following parameters:

(1) mass of the helicopter;

(2) the helicopter configuration;

(3) the environmental conditions, in particular:

(i) pressure altitude and temperature;

(ii) wind:

(A) for take-off, take-off flight path and landing requirements, accountability for wind shall be no more than 50% of any reported steady headwind component of 5 kt or more;

(B) where take-off and landing with a tailwind component is permitted in the AFM, and in all cases for the take-off flight path, not less than 150% of any reported tailwind component shall be taken into account;

(4) the operating techniques; and

(5) the operation of any systems that have an adverse effect on performance.

There is no reported steady headwind by the ATIS, but the only source for performance calculations is the windsock and, if advised by the Pilot, it indicates that the headwind is 5 kt.

According to EASA AIROPS, this wind speed of 5 kt should not be taken into account for performance calculations.