Everything below is collected in one spot so you do not have to cross-check Okayama climate: monthly averages by hand. The gap between Jan and Aug is 22.8 C here: 4.5 C against 27.3 C. No month dominates: the wettest is Jul at 7.06 mm/day, the driest Jan at 1.75 mm/day. Taken together that is roughly 1,462 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. Exact monthly values are in the table; links below cover adjacent locations and years.
Annual mean temperature 15.6 C
Warmest month Aug (27.3 C)
Coldest month Jan (4.5 C)
Wettest month Jul (7.06 mm/day)
All-time record high 35.3 C
All-time record low -3.9 C
Annual precipitation 1,464 mm / year
Coordinates 34.65, 133.93333
Population 724,691
Average monthly temperature and rainfall in Okayama
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
4.5
1.75
18.7
-3.9
Feb
5.6
2.42
19.5
-2.8
Mar
8.5
3.10
21.7
-1.6
Apr
13.4
3.53
26.1
1.0
May
18.2
4.26
31.5
5.3
Jun
22.2
6.50
33.4
12.0
Jul
26.1
7.06
34.1
16.4
Aug
27.3
4.46
35.3
17.8
Sep
23.7
6.23
33.7
12.6
Oct
18.1
4.20
29.3
6.5
Nov
12.4
2.33
24.2
1.6
Dec
6.8
2.26
22.6
-2.4
What the Okayama climate table shows
Values are multi-decadal climatological averages for the 34.65, 133.93333 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
Is Okayama climate data a forecast?
No. These are multi-decadal averages for the grid cell, not a prediction for any particular year.
Why do the numbers differ from a weather app?
An app shows one location on one day. These are long-run averages, so they smooth out single hot or cold spells.