Honshu, map

The climate of Kyoto, the ancient Japanese capital, located in the southern part of Honshu Island, is temperate humid, with quite mild winters, and hot, moist, and rainy summers. Like the rest of Japan, the city is affected by the monsoon circulation: in winter the northwest cold currents will prevail, while in summer they will be replaced by hot and humid currents of tropical origin.
The city is located about 50 kilometres (30 miles) away from the sea, in a plain surrounded by low mountains, and to the south it is practically merged with Osaka and Kobe, in a large metropolitan area called Keihanshin.

Kiyomizu-dera Temple and panorama

In winter there are fairly mild periods, with highs above 10 °C (50 °F), alternating with cold periods, with wind and rain, highs around 5/7 °C (41/45 °F) or less, and possible falls of sleet or snow. Snowfalls, however, are usually light, as are nocturnal frosts.
Summers in Kyoto are particularly hot and humid, both for the distance from the sea and the heat island effect of the big city; there can be periods of good weather, with maximum temperatures around 35 °C (95 °F) or above, tropical nights and high humidity, but also periods of bad weather, due to the summer monsoon. August is the hottest month, both for the thermal inertia of the sea, and for the lower frequency of periods of bad weather.
Here are the average temperatures.
Kyoto - Average temperatures
Min (°C)114914192324201483
Max (°C)91013202528323329231712
Min (°F)343439485766737568574637
Max (°F)485055687782909184736354

The rains are quite abundant, as they amount to 1,500 millimetres (60 inches) per year; winter is undoubtedly the driest season, at least in quantity; the rainiest months are June and July, ie the first period of the rainy season (called Baiu). In August there is a certain decrease in rain frequency: on average, among the summer months, it is the hottest, as well as the driest and sunniest.
Here is the average precipitation.
Kyoto - Average precipitation

From June to October (but especially from August to early October), Kyoto may be affected by typhoons, the tropical cyclones of Southeast Asia.
The cherry blossoming in Kyoto occurs around April the 3rd: you can take advantage of this period to visit the Buddhist temples that are located around the city (and maybe the nearby Lake Biwa), or you can go from mid-November to early December, when the trees take on the beautiful autumn colors. The area of Kyoto is indeed one of the best for the so-called momijigari, the hunt for red maples in autumn.

Temple in autumn in Kyoto

The amount of sunshine in Kyoto, all things considered is decent in winter, but it never becomes very good, however, there are two relative maxima, one in spring (April-May), and the other in August, after the Baiu rains, with around 6 hours of sunshine per day.
Kyoto - Sunshine