Everything below is collected in one spot so you do not have to cross-check Phnom Penh climate: monthly averages by hand. The gap between Dec and Apr is 4.6 C here: 26.7 C against 31.3 C. No month dominates: the wettest is Sep at 6.33 mm/day, the driest Feb at 0.40 mm/day. Taken together that is roughly 1,236 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 28.3 C
Warmest month Apr (31.3 C)
Coldest month Dec (26.7 C)
Wettest month Sep (6.33 mm/day)
All-time record high 42.8 C
All-time record low 16.0 C
Annual precipitation 1,241 mm / year
Coordinates 11.5625, 104.916
Population 1,573,544
Average monthly temperature and rainfall in Phnom Penh
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
27.7
0.52
38.5
16.1
Feb
29.7
0.40
40.5
17.6
Mar
31.2
0.97
41.5
19.5
Apr
31.3
2.07
42.8
23.6
May
29.6
4.16
42.2
23.5
Jun
28.1
6.32
38.5
22.7
Jul
27.4
5.25
38.7
22.7
Aug
27.2
5.38
39.5
22.3
Sep
27.0
6.33
39.1
22.3
Oct
26.9
5.40
34.6
19.6
Nov
26.8
2.97
35.8
16.0
Dec
26.7
0.89
37.0
16.1
What the Phnom Penh climate table shows
Values are multi-decadal climatological averages for the 11.5625, 104.916 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 Phnom 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.