BREAD HELP! Adapting to high levels of humidity.

Hilda, you could try messaging the question to boulangere, she is a wealth of baking knowledge.

Double Post Sorry.
http://carlsfriends.net/OTbrochure.html
Here's what I was reading that reminded me of this post. It mentions using a bit of vinegar to perk up a sourdough starter.
Also...
http://carlsfriends.net/source.html will send you free sourdough starter for a SASE.

I was reading about sourdough and came across a bit about PH levels in the water. Hard water makes it more difficult to get a rise. DR probably has hard limestone/coral water aquifers.
Maybe test your PH and see if the addition of a bit of vinegar or ascorbic acid will help.

Here's one discussion. http://www.thefreshloaf.com/node/7416/ascorbic-acid
https://www.quora.com/What-is-the-benifit-of-using-ascorbic-acid-with-bread-baking

I work at a bakery in S. Florida, also very humid. When I mix sour dough, I don't let it sit at all before scaling, and I rest it less than recipes require before rounding. Also, when rounding, try being much more gentle than with other white doughs.

The Case of the Dough that Didn't Bark in the Night. I mean, Didn't Rise in the Kitchen.
If the ambient (room) temp is very warm, the dough may be rising quickly, and yeast bubbles bursting, so their gasses don't stay in the dough and push the wheat around.
A few modifications can help in this...
Let your dough rise covered (in a cooking pot with the lid on, or a big dish over a big bowl, etc) at room temp.
Make it a few times, staying with it so you can observe at regular intervals, punch down if the bubbles are getting big but the dough hasn't doubled in volume, cover and let rise some more.
Let dough do a first rise, covered, in refrigerator. Bring to room temp, shape, let rise again (this time either at room temp or in fridge).
One or more of these should help...
Looking forward to hearing what you do and how it works.

Interesting question, wish I had the answer. San Francisco used to have the world's best sourdough and has a pretty humid climate, so I doubt that's the problem, and unless it's hot enough to kill yeast (in which case you probably wouldn't be baking) heating up in a warm room shouldn't be a problem. Sourdough is pretty volatile stuff, and depends on local conditions for the lactobacilli that define the flavor, but that shouldn't affect the rise much- have you tried making a simple bread with commercial yeast? That might give some insight.

The probably might not be the humidity but the flour grind itself. North American wheat flour is going to be a different quality than other flours. Even Southern USA flour which is much softer.

Go more by "Feel" when making bread with a recipe where you're using a new region's flour.
Adjust to less liquid, etc.