A consolidated reference for Hamamatsu climate: monthly averages, rebuilt from public data on a schedule. Expect 8.9 C at the coldest (Jan) and 27.2 C at the warmest (Aug) — a 18.3 C spread. Expect a wet month and a dry month but no real season: 8.06 mm/day in Sep against 2.36 mm/day in Jan. Taken together that is roughly 1,965 mm of rain a year for the grid cell. Values come from a public open API; a successful result is cached so a later outage never blanks the page. Scroll for the month-by-month figures, or jump to a neighbouring location from the links below.
Annual mean temperature 17.9 C
Warmest month Aug (27.2 C)
Coldest month Jan (8.9 C)
Wettest month Sep (8.06 mm/day)
All-time record high 32.5 C
All-time record low 0.7 C
Annual precipitation 1,967 mm / year
Coordinates 34.7, 137.73333
Population 791,707
Average monthly temperature and rainfall in Hamamatsu
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
8.9
2.36
18.6
0.7
Feb
9.5
3.15
18.6
1.4
Mar
11.7
4.33
19.6
2.3
Apr
15.5
5.91
21.8
6.9
May
19.1
6.12
25.5
10.9
Jun
22.3
7.76
29.2
16.7
Jul
25.6
7.77
32.5
21.0
Aug
27.2
5.58
32.5
22.1
Sep
25.2
8.06
31.2
17.1
Oct
21.1
7.54
27.8
12.7
Nov
16.6
3.56
23.0
8.8
Dec
11.6
2.50
22.8
2.9
What the Hamamatsu climate table shows
Values are multi-decadal climatological averages for the 34.7, 137.73333 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
Does Hamamatsu get the same every year?
Close to it. Averaging decades smooths variation, so treat these as typical rather than guaranteed.