There are several facets to your questions: room humidity, flour moisture, the flour’s rated absorption, and the method of preparing the dough. The first facet is discussed in this article by Tom Lehmann: http://www.pmq.com/mag/2006march/lehmann.php
. Flour moisture is discussed at http://www.pizzamaking.com/forum/index.php/topic,3416.msg28981.html#msg28981
, with a Tom Lehmann follow-up at http://www.pizzamaking.com/forum/index.php/topic,3433.msg29165/topicseen.html#msg29165
. As you will note from the foregoing materials, the matter of flour moisture and humidity can be quite controversial and shrouded in old wives tales, which are frequently perpetuated even by professionals whose every word is taken as gospel by followers. The matter of a flour’s rated absorption, particularly in relation to its “operational absorption”, has been discussed in this thread: http://www.pizzamaking.com/forum/index.php/topic,4646.msg39204.html#msg39204
. The way you prepare your dough, and whether you measure out ingredients by weight or volume, can also be factors that affect the finished characteristics of your dough as it comes out of the mixer bowl, as discussed at some length in the second item referenced above. In my own experiments using a modified KitchenAid dough making method involving the use of sifted flour and all three mixer attachments (whisk, paddle and C-hook), I have found that I am able to increase the hydration of a dough by several percent above the rated absorption of the flour used without the dough being wet or overly sticky, as it would be using my prior dough making methods. So, how you prepare your dough can affect its hydration characteristics.
In your case, I would start by being sure that you are using the proper hydration (which is related to the flour’s rated absorption) for the specific flour that you are using. Second, I would measure out the flour by weight rather than volume, and do the same for the water. Third, if you are running your air conditioner, that could have a slight effect on your dough and require minor hydration adjustment, assuming that your have abided by the first two steps mentioned above. If you are using old flour, or flour that has not been properly stored, then that might call for some slight adjustments in hydration. If your flour is fresh, it can have a relatively high moisture content and produce the type of results (wetness) you discussed. As you can see, even when the best of circumstances prevail, there may still be a need to make adjustments in the bowl to achieve the desired finished dough characteristics you are looking for. But, if the above steps are followed properly, in my experience the adjustments in the bowl are usually very minor, involving only a teaspoon or less of flour or water. Not fractions of a cup.
As far as oven temperature is concerned, there are many members, particularly those who make Neapolitan-style pizzas, who have successfully used very high hydrations in relation to the rated absorption for the flours used, usually Italian 00 flours. Since I don’t have a very high temperature oven I cannot comment intelligently on the merits of using super high hydrations that are considerably in excess of the rated absorption figures for the flour(s) in question. Perhaps one of our other members experienced in these matter can offer some insight on this aspect of your question.
EDIT (1/25/13): Since the link to the above Lehmann article is no longer operative, see the Wayback Machine link to the same article at http://web.archive.org/web/20110405042926/http://pmq.com/mag/2006march/lehmann.php