From September to November, and March to May every year are the best time to visit Sapa, because the weather condition is quite stable having the cool nights and sunny days. The main feature of Sapa is that its average temperature is lower than other areas. It is just 15°C.
December to February (winter)
Another different point is the Sapa’s winter usually lasts from December to February. At that time, climate may be as cold as possible even appear snow in some specific areas. As I said easier, this is one of the very attractive elements with visitors. Even, there was a certain period when this place was filled in by the home and outside visitors. They come here with the purpose of witnessing snow and making an unforgettable memory in their life.
Also in this season, if luckily, temperature drops under freezing level, you will be witnessed the whole town covered in ice (the picturesque view).
In terms of the cold level, January is the coldest period in year of Sapa on account of its cloudy and foggy features. Even the normal days’ temperature is just 8°C so everyone has to endure the coldness. There is only a little warm in February so that period is considered as a possible sign of spring appearance.
March to May (spring)
The fresh and warm springtime of Sapa is from March to May when the trees’ new buds begin sprouting and the entire town is filled in by cherry blossom. What will you do in this ideal environment like fresh air in the sunny days? Obviously, I recommend you to trek or enter the far hill tribes to have an impressive insight with their distinctive lifestyles and traditions.
In Sapa, April is also one of the months having the beautiful and good weather with many rays of sunshine even the reasonable precipitation and the low humidity. Especially, sometime you will be witnessed the chance of 4 seasons in one day of Sapa.
June to August (summer)
I know you can easily see the typical features of summer (from June to August) such as burning sunshine and hot weather in any areas in Vietnam excepting Sapa. When coming here, you will see its highlight like the stably and cool summers with the day temperature from 20°C to 25°C while the night temperature decreasing only 15°C.
However, the summer is also the rainy season of Sapa so you will not be provided the best conditions to perform a walk around this beautiful Sapa. In July, the rainfall reaches the highest landmark about 480 mm. You had better prepare full of the essential items for dealing with those rainy days as raincoat and umbrella due to they often appear suddenly in a short time. Though still August, the temperature starts coming back the stable condition, you should still visit Sapa in the peak of typhoons and rain months.
September to November (fall)
In a word, the best time to visit Sapa is during months of fall and spring seasons, because the rainfall level is lessened little by little and everything becomes milder and drier.
Meanwhile, on the fall season, you can freely enjoy a beautiful Sapa town thanks to the combination of the moderate precipitation and the stable cool temperature. From this period to November, the weather of Sapa is very nice with a little lower temperature, so this is the best option for you.