Weather: April is a warm month, and the weather is changeable. The average highest and lowest temperatures are 18 °C (64 °F) and 11 °C (51 °F).
Clothing: You may need to bring layers, as the temperature may change during the day. A thin sweater should be enough, but bring also a thin coat and some summer clothes in case the temperature becomes cooler or hotter.
April is also a good time to see flowers bloom in the hills and parks.
Early April from the 1st to the 10th is a great time to see peach blossoms in Shanghai. The peach blossom festival is held at the various peach gardens in Nanhui District. Along with enjoying the hundreds of peach trees, traditional Chinese musicians play folk music and people dance. This is also a good time to buy peach products such as jam.
Along with blooming flowers in Shanghai Arboretum, during a stroll around, see the bonsai garden and the tropical greenhouse where there are plants from the tropical areas of China. These are just two of the many many kinds of plants on display.
Shanghai Ocean Aquarium is one of the largest aquariums in China is a modern facility with aquatic creatures from five continents and a special display of habitats and animals found in China.
April is a high travel month. Weather-wise, the city is in its prime. Hotel rates will go up in a hurry. So book your rooms in advance.