The weather forecast is sunny, why is it raining?

One day, my mother came home from get off work and handed me a flat cardboard box. I opened it and found it was a light green transparent raincoat. I immediately shook off my raincoat excitedly and put it on quickly. The design of the raincoat is very special. Unlike the traditional cape-style raincoat, it has long sleeves, which allows me to move freely in the rain. I walked around the house trying out every function of the raincoat while imagining the fun of a rainy day. It wasn't until my mother called me loudly and told me not to be so crazy that I wanted to have prickly heat because I was wearing a raincoat, that I realized that I was soaked with sweat, and the cold feeling forced me to take off my raincoat.
I started to look forward to the change of weather. However, many days passed, and the sky remained blue and the night was full of stars. My raincoat has been lying quietly in the box, and the box is lying quietly in the closet. On the way home from school every day, I was thinking: Can clouds still form if the sun is so bright? Why is it that whenever I get a raincoat, the weather forecast always says sunny?
One day, as I was approaching home, the small poplar trees on the roadside suddenly rustled, as if they were whispering. After a while, a few thick clouds floated over and blocked the sun. The sky immediately became gloomy. Pedestrians on the road quickened their pace, but I deliberately slowed down, anticipating the feeling of rain hitting my head. Sure enough, a few raindrops began to fall on me, and I raised my head excitedly, enjoying the touch of the rain. I held my schoolbag in my hand and ran into the building door happily.
"Mom!" I shouted and rushed into the kitchen. "Leilei, you came back just in time, wipe your hair quickly and get ready to listen to the English lecture." Mom said. "But the lecture is still half an hour away." I muttered, hoping in my heart that my mother would notice the rain outside the window. "Then you take a rest first." Mom replied, putting garlic sprouts in the oil pan. "I'm very tired today. Mom, let me buy soy sauce for you." "I brought the soy sauce back from get off work." Mom looked at me with a smile, as if she had read through my thoughts. "Then do we want to stew the meat? The stew needs a lot of soy sauce." I said while my eyes drifted out of the window, for fear that the rain would stop. "I never said I wanted to stew the meat." Mom stewed the rice and turned around to look at me. "You didn't say it, but dad did." As soon as I said the words, I felt that I had made a mistake, because I didn't see my dad, and no one told me to ask for stew. "Really?" Mom asked. I stopped answering and didn't dare to look at my mother anymore. I quickly turned around and stared at the dish rack. The bottles and cans on it were indeed full. It seemed that my hope of buying soy sauce was gone. "Looking at the alarm clock in the room again, it was six-twenty, so I had to turn on the TV and listen to the English lecture quietly.
After dinner, the rain was still falling, pattering on the glass window, like They were playing drums to entice me to go out. I ran to the window and kept looking at the street, and I became worried: If it stops raining today, will it still rain tomorrow? Well. Miraculously, the rain stopped as I hoped. The surroundings suddenly became so quiet. I opened the window, and the cool air rushed in, and it also had a bit of fishy smell washed by the heavy rain. The road seems to be paved with a layer of bright glass; the street lights illuminate the small poplar trees on the roadside, which seem to be covered with pearl agate. If my light green raincoat can be wetted by the raindrops, it will definitely be better than the raindrops. Pearl agate is still beautiful. I threw myself on my bed and thought about the raindrops on my raincoat tomorrow. When I opened my eyes the next morning, it was still quiet. I decided not to think about the rain anymore. It was raining. Unexpectedly, when I walked to the street with my schoolbag on my back, a few drops of water fell on my forehead. I thought it was from the tree, until I raised my head to avoid the tree, and the sweet raindrops fell again. When I touched my lips, my heart felt like it was about to burst out of my throat. I ran home in a few steps, opened the cupboard door confidently, took out my raincoat and said to my mother: "Mom, it's raining, it's still raining!" "My mother tilted her head and smiled at me, and helped me fasten the buttons and put on my hat. I straightened my neck and ran down the stairs carefully. I walked on the street, swinging my two transparent green sleeves, feeling like Raindrops love to fall on my raincoat. They jump energetically on my head and shoulders: tick, tick, tick

This has nothing to do with rain or sunny days, but only with the accuracy of the weather forecast. If 66.6667% is accurate, then the probability of Mr. Jia being caught in the rain is 1-66.6667 %=1/3.
Assuming that there is no rain in this city all year round, and the accuracy of the weather forecast is still 2/3, then Mr. Jia will go out with rain gear in vain for 1/3 of the days.