As an American I would consider all of what you classified as “Southern Europe” as “Western Europe”.

In fact, we would only divide Europe into only two primary regions; Eastern and Western (which generally includes both Scandinavia and the Mediterranean west of Turkey).

The division is primarily political/historical/cultural, with geography being secondary.

Where are you from, out of curiosity?

Spain and Portugal are definitely western than all countries you listed.

Italy is as west as Germany if you check the maps.

Italy and Spain are both south Europe and western Europe.

Western and eastern Europe is a division with ancient roots that goes back to roman empire.

South and north is more geographical to separate "latin" countries from Nordic countries.

France is actually borderline, half southern, half central.

Germany, Austria, switzerland are usually referred as central Europe