HUMIDITY --- oh the humanity, so much humidity.
July 2019 for me from Irun to Santander solo, mid 50's. I echo a lot of comments here when they say it is --- Up into the mountains -- down out to the sea --- sleep, repeat. You've done the Frances you can surely do 7 days on del Norte.
For me San Sabastian to Zarautz, Zarautz was full so I had to make my way additional k's to Getaria where I took a rest day because yes, del Norte is no joke.
Deba to Markina was my most difficult day as I was following someone going the wrong way first thing leaving Deba then I got lost in the mountains because I missed a small arrow on a tree trunk. It took me 12 hours to get to Markina where I took another rest day. Once you pass the last cafe going to Markina it's up, up, up, up, will it ever end? Nope, up and up some more. But it's all doable, just dig deep and see what you're made of.
I felt safe but had my guard up entering Bilbao (for good reason, long story. I’ve posted somewhere on the forum) and a few other places. Just pay attention as you hopefully would in normal life.
Just do it! Go for it! There’s always options if you feel you need to get out which I did. I was completo by the time I made it to Castro Urdiales where I took another rest day and decided to switch, so I planned to take a train from Santander to Fromista going back to the
Camino Frances where I finished to Santiago. No judgments on the Camino.
The beauty outweighs the difficulties as it should on a Camino, it is what it is, different, different for each pilgrim. Buen Camino!
Out of San Sabastian
On the way to Markina
There is so much more to see...........GO FOR IT!!