Aurora borealis are rare in the Netherlands. But is it as rare as seeing one in lower latitude countries (like those in the mediterranean)? Is there more probability of seeing an aurora in the Netherlands than in other lower latitude countries (e.g., France or Spain), or is the likelihood roughly the same?
Depending on where you are within the country it is a 'once in a lifetime' occurance or maybe a 'once in a year' one.
There are locations which have no light polution to the north, good open flat country or sea. In such location it is less unlikely to see the coloured light in the sky, but it is still very rare and I am told never the overwhelming experience it can be more to the north.
I have never seen them, in more than half a century in the Netherlands, my brother who lives in the same village a few times, but he is often about in his car by night, I am not.
As far as I understand your chances of seeing the lights are much more rare in France, only a few locations it is possible at all, no chance further south.
I have never been to Netherlands and thus cannot share any first-hand experience; however, I know about multiple reports and photos of aurorae seen from Slovakia and Hungary in the last few years. The countries have different topography but are not too far away from Netherlands.
There are at least three important factors that need to be considered:
Geographic latitude, or more precisely, distance from the magnetic north pole. Slovakia is at 49° N while the northernmost extremities of Netherlands are close to 53.5° N. This is some 400 kilometres closer to the geographic north pole. As the north magnetic pole is currently in northern Canada, the difference is actually closer to 800 kilometres, which is definitely a significant advantage for Netherlands.
Light pollution, which is much worse in flat and densely populated Netherlands than in rural and mountainous Slovakia. Also the proximity to the ocean means higher humidity, which results in worse observation conditions on average.
Altitude. In Slovakia, virtually all aurora sightings were reported from high mountains (1500-2500 metres), where the air is clearer and northern horizon is more readily observable. From flat Netherlands it would be certainly more difficult to see.
Considering all this I'd say Netherlands has a very slight advantage. Extrapolating further south:
- Northern France is not far away from Netherlands, it is also flat and light-polluted. Basically the same arguments apply and aurora sighting frequency should be comparable, maybe slightly lower.
- Southern France is much further from the magnetic north pole but has the advantage of very high mountains and lower light pollution. The frequency of aurora sightings should be slightly lower for high-altitude sites but definitely much lower at low altitudes.
- Spain is even further out to the south, but rural areas are at relatively high altitudes and light pollution is low. A quick search of the internet reveals aurorae have already been observed from Spain, but seem to be very rare.
- In southern Spain, aurorae are extremely rare, but probably still possible during times of exceptional solar activity.