The Climate of Laos
Lao PDR is the one country in Indochina that is completely surrounded by land, with no coastal area. Most of the country is hilly or mountainous. The country's weather is dominated by the Asian monsoon, with the north monsoon blowing from Nov-Mar and the south monsoon from May-Sep. A transition period exists between the two monsoons, during which winds are light and variable.
Laos has one single rainy season during the south monsoon ( May to Sep), the rest of the year being drier with infrequent rain and much sunshine.
Temperatures are generally high during the entire year, but in the mountains in the north, there are sometimes colder days in winter during the north monsoon. These cold periods are associated with outbreaks of cold air from central China. The lowlands further south are sheltered from these outbreaks, and the dry season here is hot and sunny. Humidity is much lower during the dry season, so despite the heat, weather conditions are more pleasant than during the cooler wet season when humidity is higher and the weather feels muggy and oppressive.
Very occasionally, a typhoon from the South China Sea may cross over land to affect the country during the South monsoon. When this occurs, there is widepread torrential rain and strong wind.
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Vientiane
|
| Month |
Rainfall(mm) |
Temperature (Celsius) |
| Ave. Monthly |
Ave. No. of Days with 1mm |
Average Daily |
Lowest Recorded |
Highest Recorded |
| Min |
Max |
| Jan |
7 |
2 |
11 |
29 |
2 |
34 |
| Feb |
19 |
4 |
13 |
31 |
7 |
38 |
| Mar |
36 |
5 |
16 |
33 |
12 |
40 |
| Apr |
111 |
9 |
22 |
34 |
15 |
40 |
| May |
255 |
12 |
24 |
33 |
19 |
38 |
| Jun |
301 |
11 |
24 |
32 |
19 |
39 |
| Jul |
259 |
18 |
23 |
32 |
18 |
34 |
| Aug |
299 |
21 |
24 |
31 |
20 |
36 |
| Sep |
272 |
15 |
23 |
32 |
17 |
34 |
| Oct |
120 |
9 |
22 |
31 |
15 |
35 |
| Nov |
31 |
6 |
19 |
29 |
9 |
34 |
| Dec |
10 |
3 |
17 |
28 |
4 |
34 |
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