Worse than a light rain, is a light rain in Las Vegas, where there is very little rain between oil build-up.
When we first moved there, I saw a Sportster try to slow for a right turn at rather slow speed and almost lose it.
The only time I was caught in serious rain I was on a XVS950 and a friend on a Gold Wing rode from Las Vegas to Cedar City then east on Utah 14 to Duck Creek. Leaving Duck Creek going to Bryce Canyon, a downpour started on 14 west of 89...no place for cover. No worries about oil so we rode at normal speed down the twisties. In a short time, the sun reappeared and my T shirt and Wranglers were dry in a VERY short time. We got drenched again, leaving Bryce.