think your going to get this more and more gary as you just publish your map with stations online without any consent to be used on that page itself , your taking weatherflow stored data which most will give consent but your not requesting consent its the trust factor as most will trust a brand over a end user page . to me its makes no difference but the amount of skeptical paranoia based on GDPR about you will get these questions and concerns .
you need to come up with a solution that gives the end user an option and that may mean you collaborate with weatherflow and implement an option. .
until,you get the consent you dont publish
that option has to be very very made aware of because unless they are aware of your map thing then they will never have had the option to consent thats where you may hit teething issues .hence collaboration.
you may find this all rather unnecessary but i have two clients who spent thousands last month adressing these concerns just because the law now requires some form of consentional use .
you have to view it from outside your own back door and privacy has become very very topical and often media will,exaggerate the problems to get the readership , people,believe what they read regardless of source .
right now you dont have many europeans online with the hardware but in due course that will change and you may find this skeptical view more common.