Your phone is probably screwed if it was out in the rain all night long, but a bag of rice will do absolutely nothing but waste precious time. All the rice does is absorb surface moisture and give some placebo effect to the feeble minded.
See if you can find a desiccant pack somewhere locally, or overnight it from amazon. That's your only chance.
Wut? A dessicant pack will literally do the exact same thing as rice. There's nothing magical about it, all it does is absorb moisture, just like rice.