"Neither snow nor rain nor heat nor gloom of night…"
No, I don't work for the Postal Service, but I figure if they can deliver the mail walking around outside in actual weather, I can certainly pedal my silly little bike in it.
Water won't hurt your bike. You do get it wet to wash it, don't you? Then you've already discovered this. Rain won't hurt you. You do take showers or baths, don't you? Then you've already discovered this. Actually, just imagining the warm rains you must have in AZ makes me jealous.
As for weather forecasters, I've rechristened The Weather Channel™ as The Hyperbole Channel™. Never have I seen so many people get so lathered up over nothing. A few flurries causes them to foam at the mouth over the potential for it to wreak havoc over a wide path of destruction. C'mon. It's a snow flurry. They're pretty, and fluffy.
Their forecasts for rain are typically amped up by 20 or 30% or more. I've can't count the number of times I've ridden when they've said it's raining, and instead, it's dry as a bone outside. Same for snow. They'll forecast a foot, and we get a couple of inches. So whatever The Hyperbole Channel™ says, I turn it down a few notches.
In the desert southwest, you probably don't even need raingear, just get wet and and dry off at your destination. In the summer, that's all I do around here. Over about 50 or 55, it's just too hot and steamy inside raingear. I get soaked with sweat instead of rain. Since I'm going to get soaked anyway, I'd rather it be rain.
For the few times a year you get rain out there, full coverage fenders are probably overkill. I use
Bontrager Satellite quick release fenders on my 30-50% chance of rain bike. The quick releases mount to the brake bolts, and the fenders clamp into the quick releases in seconds--literally. Keeps my backside and face clean. The rest washes off at home--with water.