There will be many opinions on this, across the Forum. But, from my Camino experience, I can cut to the proverbial chase...
- If you are wet and warm, this is not necessarily a bad thing.
- If you are wet and cold, it is ALWAYS a bad thing.
Thus, you want (IMHO) to have enough outer garments and variety to level according to need.
If the day is raw, or there is a ground fog or drizzle (a common thing in May), I usually add over the fleece, my international orange Marmot lightweight wind and rain parka, with the pit-zips open all the way to vent perspiration. You WILL get drenched from perspiration. But, as stated at the outset, warm and wet is good, sometimes VERY good. But cold and wet always leads to a bad situation. I had hypothermia my first year out. All of the information contained here was gleaned from three Caminos, all in the late April through end of May timeframe.
If it starts to rain or snow continuously (as opposed to "spitting") I usually add my Sea-to-Summit siliconized nylon ultra-lightweight poncho (lime green). The poncho is well ventilated, weighs nearly nothing (truly), and provides protection to me and the rucksack. FYI, you can have snow at elevations above about 700 meters into late May.
If perspiration becomes a problem, I can rearrange these three basic outerwear layers to suit. For example, if cold but not overly wet from perspiration, I might put the orange Marmot parka away, retaining the fleece and the poncho. If the sun comes out, and the Spanish sun is always hot, the fleece might get packed away as well, leaving the poncho over the polo-shirt.
Here is my layering scheme:
Over my Underarmour short-sleeve polo shirt (favored over a t-shirt because the collar can be turned up to help protect the exposed neck), I first put on a North Face zip-front Polar Tec fleece jacket. It is light grey. This is usually every morning, as early morning temperatures even in May, can be 4-6 degrees Celsius when you first start out.
Also, I use a neon lime-yellow, Adidas "Adizero" ball cap (seen in my Avatar photo to the left) as a bill to extend the poncho hood. Conversely, wearing an around-the-head wide brimmed sunhat under a poncho channels precipitation to the rear of your head, down your back, and into everything, including your rucksack, via the back panel. Sun hats should be worn in hot sunny weather. I carry both a ball cap and a sun hat (folded until needed).
In addition to this, I carry a microfiber Buff in a rear-side pocket. Actually I carry two, one to each rear-side pocket. I can give one to a needy pilgrim, or have two to cover up. I have also used a Buff as an expedient compression bandage. I fell on my head on Camino #2 and bled like a proverbial stuck pig. My error was in hopping over a wire fence with my rucksack on, bad balance, dumb idea. I placed a full packet of tissues under the Buff to hold it in place. It worked perfectly! So, carrying two is a good idea. It was a tiny wound, put being on my head, it bled profusely until it clotted over some hours later. BTW, I now carry wound clotting powder as well in my first aid kit.
If it turns unusually cold or raw, OR if I have to sleep someplace with inadequate heating, I also have a one quart / liter ziplock bag with a neon-yellow microfleece watch / beanie cap and a pair of microfiber Champion brand runner's gloves with reflective strips. I bought the cap at a Carhartt work clothing dealer and the gloves, inexpensively, in a Target department store. Again, a LOT of protection for not much weight.
NOTE: You might have noticed that I favor bright, safety-like colors in my outerwear, where possible. That is intended to provide a high degree of unnatural contrast against my surroundings so I can be readily seen when road walking. On my first Camino, I favored flashing LED lights on me and my walking sticks. But, this is redundant weight compared to just choosing bright safety colors that do not exist in the environment. So, by Camino #3, I ditched the extra weight in favor of dressing like a tropical bird. Combined with strips of 3M reflective tape on my walking sticks, it seems to do the trick. The oncoming drivers may die of laughter at seeing "the walking parrot," but they WILL see and avoid me. And THAT my friends is what matters.
No, I do not care what I look like. I would prefer being seen and avoided than have to explain to my family why I left vertical and returned horizontal...or worse... besides, my trousers are muted colors, and my fleece jacket is grey. So, once I get where I am headed, I can tune-down my color temperature...
I am now packing to leave for Madrid in one week, Monday 4 April, to walk from Madrid to Sanitago, starting on 7 April. Everything I mentioned above is now spread on my living room floor, in addition to a myriad of other stuff, waiting to be checked off my list, packed and arranged in my rucksack.
I hope this helps.
