The majority of scooters are not intended for riding in the rain.
Except the Smolt and co Z1000 V2 and the new X series
If you are still riding, avoid puddles of water, put protection on the screen (you can use plastic food film). Anticipate braking, because it slides easily in the rain and put on a helmet, and gloves, it's more careful.
For the Xiaomi
In addition to protection on the on/off button. Check the cable passages at the front black plugs, at the rear brake cable and passage of the taillight wire in the chassis. Because water tends to seep through. A filler can fill this
The plate under the battery has an original waterproof seal check that all the screws are tight and present.
Do not refill if damp and do not turn over.
Water + electricity = danger
The warranty may be refused if the humidity detectors are red inside the chassis