I live in a place called the country with the crappiest weather ever right now and i live in a no fly zone so weekends i go places and... it RAINS dammit DJI start selling a nice weather care refresh! ;)
Over here where I live when the winter kicks in then I won't be flying but when the Fall, Spring and Summer seasons comes around then it's time to maximize the fun level. Trying to get in as much flying as possible before the cold set in. Yikes !
I recently flew my MP in a light shower. Where I was on the ground it was perfect, overcast and dry, yet some 800mtrs away it was raining. I couldnt see it on my Iphone screen video feed, but when the MP returned, it showed signs of dampness. No issues with performance, but I personally wouldnt fly in wet weather.
One of my first flights I had to bolt the drone back since it suddenly started to rain lightly. Only had a few drops around the body and one on the camera but nothing around the battery or air intake/exhaust ports and no damage to anything. The funny thing was I went back and looked at the footage and it was only raining on the part where I was standing and the drone was flying in an area where it wasn't raining. It only went through about 10 seconds of the light shower too.
In reality, it's actually built to probably withstand a lot more abuse, but I personally won't ever use it in any type of precipitation.
I live in California and we spent the last 5 years praying for rain.
That said, I did see a posting that pointed out that the topside of your quad has no holes for water to run into, so a light rain shouldn't hurt anything. Landing in water with all the openings on the underside? A bit different.
If it starts to rain during the flight then get it back to you and land safely ASAP and get it in the case/bag - another reason not to fly 'miles away' - the longer it's exposed the higher the risk of the battery malfunctioning and the drone crashing should it start to rain mid flight. Don't take off even if it's currently not raining but showers are forecast. Always check weather conditions as part of your pre flight planning and never fly in the rain, falling snow or even mist, fog and especially clouds. Moisture of any description can make lipo's set fire and the Mavic is not water resistant. You wouldn't sit on a park bench in the middle of downpour and get your MacBook out... Same principle.