Basically, spring and fall are the nice seasons in the Osaka area, with quite cold winters and hot, muggy summers.

This is a link to current Osaka weather information:       Osaka Weather Forecast Info

In winter, temperatures are just above freezing, and people wear winter coats, hats, gloves, and scarves, but it rarely snows. Jan. 15 is a good day to take pictures of young ladies wearing kimono for their Coming-of-Age ceremony, and the Setsubun holiday on Feb. 3 is the day to throw dried beans at bad luck, and also eat your age plus one. The new year's holidays until Jan. 4 are a quiet time with many places closed, but the shrines are full of well-wishers. Xmas is not so much a religious holiday as a splash-out date for young couples, and the shops are filled with the usual decorations.

In spring, the temperatures stay chilly until May, so people wear light jackets and sweaters, and enjoy the beautiful cherry blossoms with "Hanami" (cherry blossom viewing) parties, usually in April. Every park has dozens of groups picnicing, but Osaka Castle Park is one of the main parks for Hanami. In March the plum blossoms are also beautiful, but people don't have Hanami then. The last two weeks of March is when Osaka hosts the Spring Grand Sumo Tournament, and tickets can usually be bought on the morning of the day (at the Osaka Prefectural Gymnasium near Namba). The Golden Week is a string of national holidays from April 29 to May 5, so trains and attractions can be crowded at that time. 

Rainy season lasts for about a month from mid-June to mid-July, and although it usually doesn't rain ALL day long, it does rain most days, so of course people carry (and lose!) their umbrellas.

In summer, temperatures are in the low 30s Celcius (high 80s F) with very high humidity. When not working, people wear shorts, t-shirts, & sandals, and carry a paper fan or wrap a hand-towel around their necks. Air con is readily available in shops, etc., but outdoor sightseeing is sweaty & tiring. Very large fireworks festivals are held in the evenings at various places throughout the summer, with the main one for Osaka being along the Yodogawa River in August. The Tenjin Matsuri is THE main festival for Osaka City, held every July 24-25 near Tenmabashi, and should not be missed if in town then. During the Obon period of Aug. 13-15, many people return to their hometowns so travel is busy during that time.

In fall, the temperatures stay quite warm until November, and people enjoy taking walks in parks & forests to enjoy "koyo", the fall colors changing on the maple trees. The park and waterfall at Minoo, to the north of Osaka at Hankyu Minoo station, is one popular place for this. Typhoon season is usually around September, but Osaka only gets hit about once a decade. The Danjiri festival in Kishiwada (near the Kansai Int'l Airport) on Sept. 14-15 is thrilling and worth plunging into the crowds. The Midosuji Parade travels down Osaka's main boulevard in mid-Oct.