I would never go without a rain jacket/shield of some type here, especially for any trip more than 1 day which is about as far as the weather is predictable here. I take rain pants infrequently (usually not before mid-October) and only as an additional warming layer and to stay drier if I will be sitting a lot.
Not taking a rain jacket can be dangerous in some situations. Just as an example, I have seen guys (especially thin guys) get hypothermia in the tropics inside of 6-12 hours despite intermittent activity, because they were wet continuously. And this is with air and water temp's above 70 degrees. The extremities can take mild temps like that for a long time, but if you let your core and head/neck get cold and wet for a prolonged time without putting putting back heat through activity or other means, then you are in trouble. Luckily, for mild hypothermia in the tropics, it was easy to treat these guys by just getting them into a gortex bivy sack without any wet clothes on, which started to warm them at those temps almost immediately.
With a rain jacket, rain hat, dry feet/boots, and gaiters (gaiters which I like to wear under my pants in really wet brushy conditions), the only thing that is exposed and gets wet, is the front of the thighs of your pants. That is a nuissance at most, and will dry quickly generally depending upon the pant type as soon as you quit walking through wet brush, as long as your core is warm.