Everything below is collected in one spot so you do not have to cross-check Kumamoto climate: monthly averages by hand. The gap between Jan and Aug is 22.1 C here: 4.3 C against 26.4 C. Precipitation peaks in Jun (12.77 mm/day) and bottoms out in Jan (2.21 mm/day), so a 5.8x difference between the two. Taken together that is roughly 2,126 mm of rain a year for the grid cell. The build runs on a schedule and caches the last good response, so the numbers stay put even when the upstream API is having a bad day. Exact monthly values are in the table; links below cover adjacent locations and years.
Annual mean temperature 15.3 C
Warmest month Aug (26.4 C)
Coldest month Jan (4.3 C)
Wettest month Jun (12.77 mm/day)
All-time record high 35.5 C
All-time record low -5.2 C
Annual precipitation 2,128 mm / year
Coordinates 32.80589, 130.69181
Population 738,907
Average monthly temperature and rainfall in Kumamoto
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
4.3
2.21
18.5
-5.2
Feb
5.8
3.57
20.0
-4.5
Mar
8.8
4.18
22.5
-3.2
Apr
13.5
5.22
26.4
1.1
May
18.3
5.87
30.8
5.6
Jun
21.9
12.77
31.6
10.8
Jul
25.6
12.71
35.2
17.2
Aug
26.4
6.86
35.5
16.1
Sep
23.0
6.90
33.6
11.8
Oct
17.4
3.79
30.2
3.8
Nov
11.9
3.19
25.9
-0.9
Dec
6.4
2.66
22.1
-5.1
What the Kumamoto climate table shows
Values are multi-decadal climatological averages for the 32.80589, 130.69181 grid cell, not a single year. Rain is the daily mean, so a value of 2.00 mm/day is about 60 mm across a 30-day month. Averages smooth over extremes, so use them for planning rather than for what to pack for next Tuesday.
Frequently asked questions
How much rain is 12.77 mm/day in a month?
Rain is recorded as a daily mean, so 12.77 mm/day is roughly 388 mm across a 30-day month.
Does Kumamoto get the same every year?
Close to it. Averaging decades smooths variation, so treat these as typical rather than guaranteed.