Hi, MelaCro!
Welcome!
I can't say for sure, and it likely depends somewhat on the year (changing weather patterns), but in some ways I suspect that August may be not quite as hot as July (especially after mid-August).
I walked the Camino Francés in the last part of June and most of July in 2012 and 2015. There was a heat wave each time, and in 2012 I promised myself I'd never walk another summer Camino, but last year I went back and did it again, and loved it!
Last year was a busy time, with many pilgrims on their way to Santiago in time for the July 24-25 birthday celebration, but I still always found a bed at an albergue. The only place I booked in advance was for Santiago but that was because I arrived on July 23rd. (The municipal albergues in Arzua and Arca do Pino (O Pedrouzo) were full then, but that was to be expected so close to the 24th.)
Do you have any idea yet of how many kilometres you might like to walk each day? Much depends on that, along with how fast you walk. I range from 3.5km/hr up steep hills, to 5km/hr nearer the end of the Camino when my body is fully conditioned again and I'm going along at a good speed (my usual average is 4.5km/hr).
My first two Caminos were in September/October and I remember hearing about summertime pilgrims getting up to start walking at 5am and thinking, "Those people are crazy, and that will never be me in this lifetime!" However, a few days of walking in June on my third Camino and I was very happy to join the 4:30am club! That to say, if you start walking at 5am, and plan to walk 20km, you'd likely be done by about 11am (depends on how many breaks you take for photos or food or bathroom trips).
It's nice to be able to stop by 11am when it gets hot. But last year I was blessed to meet a few people who actually enjoyed walking in the heat of the day, and they taught me that not only is it possible, but when I tried it, I discovered I quite like it too! As long as you have enough water, and are sensibly dressed and sun-protected, and pay careful attention to your body's signals, there's really no reason why walking through the day can't happen... in my experience and that of my friends. Your experience and decisions might be different from that, and that's okay too!
I hope that helps a little.
Your body will become conditioned. It takes me about 7-10 days to get back into the stride and rhythm of things. And after my first year when I ended up with knee trouble from walking too far and too fast the first week, I now take it easy for the first while. I know I'll have strength and endurance to walk longer days later on.
Buen Camino!
Rachel
