Weather sensors required for ILS approach operations?
Whether or not an ILS may be conducted without proper weather reporting will depend on the regulations under which the flight is operated.

In simple terms, a flight operated under 14 CFR 91 may perform an ILS without this weather reporting.

This may also be allowed under the eligible-on-demand rules of 14 CFR 135, if all pertinent requirements are met.

Otherwise, a flight operated under 14 CFR 135 or 14 CFR 121 will generally not be approved to conduct an ILS without approved weather reporting.

This answer applies under FAA jurisdiction.