Anyone been noticing the warming of Phnom Penh during the past decade or so? My wife, who grew up in Phnom Penh near the Central Market, remarked to me lately how much hotter it is now than when she grew up. I have noticed it too just in the past dozen or so years in Russey Keo. A decade ago there was water for 300 meters behind our house, fish ponds, and a big lake stretched far in both directions. Trees to the side of and nothing high in front. Now that 300 meters is completely filled with multi-story cement buildings, side and front too. We used to always have a cool breeze blowing through our house, now there is never a breeze. We used to love to sit outside, now we never do. I knew the area would be built up eventually, I just never imagined it could happen so blazingly fast and with such a dramatic effect on our local climate.

The same thing is happening all over the city, high rise buildings blocking the breeze, hot cement replacing the many lakes, especially Boeung Kak, that once cooled the city. A once wonderful city where you could live without air conditioning, now, hardly anybody in the city does. And all that air conditioning increases the heat as well.

Not only heat, but a badly damaged watershed, water that used to soak into the ground and be held back by the many lakes, now has nothing to hold it back.

Interestingly HS recently said, “What I hate the most is that when there is a flood, some people curse us saying it is because [we] have filled in lakes. Do you understand the word flood? If the water coming and going is not balanced, there will be a flood," seemingly oblivious to the critical part lakes play in buffering water flow in a healthy watershed.

(www.phnompenhpost.com/national/hun-sen- ... ng-capital)

Found these studies, where at least a few people are starting to look at the problem, too late maybe, but at least some Khmers are now thinking about it. Don't know if there are any studies looking back at historical temperatures in Phnom Penh, compared with the present. A lot was probably lost during the Khmer Rouge time, but it would be interesting to see city temperatures through the decades, if they exist.

https://khmerstudies.org/the-impact-of- ... phnom-penh
https://build4people.org/project-outline/

This is not meant to sound like a tirade against progress, far from it, I for one am excited about about many of the changes happening here, making lives much better for many, however sometimes just building and having more stuff is not progress if it makes your surroundings less livable anywhere outside the protection of air conditioned glass and concrete interiors. And all this, while it affects everyone, affects the poor much more than the wealthy, who can afford to mitigate their environment.

Was wondering if any of you long timers here have seen any heat island effects here similar to what my wife and I have witnessed or know of any historical temperature records.

I've talked to people here who recall being able to see their breath in the morning as normal.

AE86 wrote: ↑Sun Feb 13, 2022 2:26 pm I've talked to people here who recall being able to see their breath in the morning as normal.

Thanks, your post me curious as to what temperatures you can begin to see your breath. Looks like a temperature up to 13C (55.4°F) could show your breath with high enough humidity. Or more likely a bit below, maybe down to 10C (50°F).

So based on that a good guess might be the morning temperature here was around 10 to 13C (50 to 55F) and certainly below 15°C (59°F), which is quite a bit cooler than now.

The French must have kept records when they were here, I wonder if they are still around somewhere.

I found this info on Quora by E. Groeg, B.A. from University of Sydney. he said, "...seeing your breath has ... to do with the combination of temperature AND relative humidity.
At its warmest, your breath can show at around 13°C (55.4°F) — Provided that the relative humidity is very high, like above 95%... That’s the warmest in my experience. I think it’s very rare to see your breath at 15 °C (59°F)... Generally speaking, with decent amount of humidity (say around 80% at least), your breath can start to liberally show at 10°C (50°F)...."

His unedited answer is here:
https://www.quora.com/At-what-temperatu ... hs-outside

CaliforniaGuy wrote: ↑Sun Feb 13, 2022 2:06 pm Was wondering if any of you long timers here have seen any heat island effects here similar to what my wife and I have witnessed or know of any historical temperature records.

Hope this helps https://www.timeanddate.com/weather/cam ... h/historic

There's always the Riverside for a nice cooling breeze though,I don't think they'll be filling in the mighty Mekong anytime soon?

Sarcasm on...

Nah...... has nothing to do with buildings, concrete or or cutting down trees.... or filling in lakes for that matter. It's Global Warming (cough, cough) I mean "Climate Change".

Sarcasm off.

mossie wrote: ↑Sun Feb 13, 2022 9:25 pm

CaliforniaGuy wrote: ↑Sun Feb 13, 2022 2:06 pm Was wondering if any of you long timers here have seen any heat island effects here similar to what my wife and I have witnessed or know of any historical temperature records.

Hope this helps https://www.timeanddate.com/weather/cam ... h/historic

Thanks, it does.
At the site you gave they have a historical chart for Pochentongh, near the airport about 9km from Phnom Penh. Looking at the coldest month, January, for the years 2005-2010 their chart high and low January temperatures are 31 and 22. From the annual data at the site 9km outside of PP, which goes from 2010-2022 you can find high and low temperatures of 34 and 21, with a yearly range 2 and 4 respectively (I could not upload my images, maybe too large). So Looks like not any real difference for January temps between the 2005-10 and 2010-2022 periods. From this I would venture to say there has not been any significant temperature change in the Pochentongh area from 2005-2022.

However, the temperatures are from the Pochentong/Airport area outside of the Phnom Penh heat island. So while the surrounding region has not changed, any change must be localized to the urbanized Phnom Penh areas. Maybe the micro climate changes are quite localized, possibly not much right alongside the riverside, but more in areas like Russey Keo, or other similar places, which were once flat, rural and wet but are now more high rise, urbanized and dry.

AE86 wrote: ↑Sun Feb 13, 2022 2:26 pm I've talked to people here who recall being able to see their breath in the morning as normal.

Could this have been in the period before 1970? There was a global cooling period between 1950-1970.

^^^Most of whom I talked to were in their 50's or 60's and were recalling childhood or early adolescent memories, although some people I remember mentioning were saying as early at 10-15 years ago it was also that way in the provinces such as Mondulkiri or Ratanakiri.