Could you tell me how to read General Affairs Bureau rainfall information?

http://translate-en.city.yokohama.lg.jp/ex/kikikanri/weather/top/fire_rain.html

The "hourly rainfall" of each fire department does not mean the rainfall every 15 minutes, but the rainfall for 60 minutes at that time.
For example,

(１) Time: 16:00
Hourly rainfall: In case of 7.0 mm
→The rainfall from 15:00 to 16:00 is 7.0 mm.
(２) Time: 13:15
Hourly rainfall: In case of 30 mm
→The rainfall from 12:15 to 13:15 is 30 mm.

If you want to check the 15-minute rainfall, 30 minutes rainfall, 3-hour rainfall, 12-hour rainfall, and 24-hour rainfall, select the display switching "List" on the left of the screen and check the rainfall information of the relevant fire department . Even in that case, the rainfall during that period is displayed retroactively to 15 minutes, 30 minutes, etc., from the display time in the upper left.
In addition, the cumulative rainfall represents the total rainfall since the beginning of rain, but if the rainfall continues for three consecutive hours, it will be reset to 0.