Do you need to know, when is the best time to go to Southwest? Then you should take a look here, what weather you can expect there during the year.
Southwest is part of China. The climate of China is very diverse, because the country is very large. Weather is tropical in south and subarctic in north, and alpine in the higher elevations of the Tibetan Plateau. Monsoon winds strongly influence the climate. During the summer the Monsoon carries warm and moist air from the south, during winter the monsoon brings cold and relatively dry weather.
When speaking about the usual weather in this area, the information is relevant for example for these popular places: Anshun, Baise, Bayi, Beihai, Benzilan, Bingzhongluo, Central Guangxi, Central Yunnan, Chengyang, Chongzuo, Chuxiong, Congjiang, Dali, Deqin, Detian, Dongxing, Dram, Eastern Yunnan, Fuxian, Gejiu, Guangxi, Guilin, Guiping, Guiyang, Guizhou, Gyantse, Haba, Hechi, Heijing, Hekou, Hepu, Hezhou, Jianshui, Jinghong, Kaili, Kunming, Kunming Prefecture, Lang De, Lhasa, Lijiang, Liuku, Liuzhou, Longsheng, Longzhou, Lugu Lake, Mengla, Mohan, Nagqu, Nanning, Ngari, North Guangxi, Northwestern Yunnan, Nyalam, Nyingchi, Pingxiang, Pu'er, Qamdo, Qomolangma, Rongjiang, Ruili, Sakya, Samye, Sanjiang, Shangrila, Shannan, Shaxi, Shelkar, Shengping, Shilin, Shiping, South Guangxi, Southeastern Yunnan, Southern Yunnan, Tengchong, Three Parallel Rivers National Park, Tibet, Tingri, Tonghai, Tsethang, Weining, Weishan, Weizhou, Western Yunnan, Wuzhou, Xidang, Xigatse, Xijiang, Xingping, Xishuangbanna, Yangshuo, Yarlong River National Park, Yizhou, Yuanyang, Yubeng, Yulin, Yunnan, Yuxi, Zhaoxing, Zunyi.
Let's look now what weather you can expect in the area around Lhasa and in many other cities. The warmest month here is June, the average maximum temperature is 23.3 ℃ (73.94 ℉). The average minimum temperature in this month is 9.4 ℃ (48.92 ℉). The coldest month here is January, the average maximum temperature is 7.2 ℃ (44.96 ℉). The average minimum temperature in this month is -9.7 ℃ (14.54 ℉). The most rainy month here is August, the average number of rainy days is 15.6. The least rainy month here is January, the average number of rainy days is 0.2. 
When travelling around Southwest, always consider the altitude of the the place as well. We should remind you, that the highest point in China is Mount Everest (8848 m) and the lowest point is Turpan Pendi (-154 m). So there are huge differences in altitudes in this country and the weather is very different in them therefore. Keep in mind, that the temperature usually decreases by 1.2 - 1.9 ℃ (2.2 - 3.5 ℉) per 200 m (656 ft), depending on the other conditions. (And we should add, that in the very special condition named thermal inversion even the temperature may be higher in higher altitudes.)
Typical (usual) weather in Southwest in January is this: The average highest temperature in Southwest in January is 7.2 ℃ (44.96 ℉). The average lowest temperature is -9.7 ℃ (14.54 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 7.45 ℃ (45.41 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 8.1 ℃ (46.58 ℉). The average number of rainy days in January is 0.2. The average rainfall is 0.5 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 10:16 (hours and minutes), in the middle of the month 10:26 and at the end of the month 10:44.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in February is this: The average highest temperature in Southwest in February is 9 ℃ (48.2 ℉). The average lowest temperature is -6.6 ℃ (20.12 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 8.1 ℃ (46.58 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 10.7 ℃ (51.26 ℉). The average number of rainy days in February is 0.2. The average rainfall is 0.7 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 10:44 (hours and minutes), in the middle of the month 11:07 and at the end of the month 11:33.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in March is this: The average highest temperature in Southwest in March is 12.4 ℃ (54.32 ℉). The average lowest temperature is -2.8 ℃ (26.96 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 10.7 ℃ (51.26 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 14 ℃ (57.2 ℉). The average number of rainy days in March is 0.5. The average rainfall is 2 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:33 (hours and minutes), in the middle of the month 12:00 and at the end of the month 12:27.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.
Typical (usual) weather in Southwest in April is this: The average highest temperature in Southwest in April is 15.6 ℃ (60.08 ℉). The average lowest temperature is 1.1 ℃ (33.98 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 14 ℃ (57.2 ℉). At the end of April you can expect higher temperatures, the average highest temperature is around 17.45 ℃ (63.41 ℉). The average number of rainy days in April is 1.3. The average rainfall is 5.2 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:27 (hours and minutes), in the middle of the month 12:53 and at the end of the month 13:17.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in May is this: The average highest temperature in Southwest in May is 19.3 ℃ (66.74 ℉). The average lowest temperature is 5.2 ℃ (41.36 ℉). At the beginning of May you can expect lower temperatures, the average highest temperature is around 17.45 ℃ (63.41 ℉). At the end of May you can expect higher temperatures, the average highest temperature is around 21.3 ℃ (70.34 ℉). The average number of rainy days in May is 5.2. The average rainfall is 26.2 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 13:17 (hours and minutes), in the middle of the month 13:38 and at the end of the month 13:53.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.
Typical (usual) weather in Southwest in June is this: The average highest temperature in Southwest in June is 23.3 ℃ (73.94 ℉). The average lowest temperature is 9.4 ℃ (48.92 ℉). At the beginning of June you can expect lower temperatures, the average highest temperature is around 21.3 ℃ (70.34 ℉). At the end of June you can expect lower temperatures, the average highest temperature is around 22.7 ℃ (72.86 ℉). The average number of rainy days in June is 9.8. The average rainfall is 72.5 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 13:53 (hours and minutes), in the middle of the month 14:02 and at the end of the month 14:01.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in July is this: The average highest temperature in Southwest in July is 22.1 ℃ (71.78 ℉). The average lowest temperature is 10.5 ℃ (50.9 ℉). At the beginning of July you can expect higher temperatures, the average highest temperature is around 22.7 ℃ (72.86 ℉). At the end of July you can expect lower temperatures, the average highest temperature is around 21.75 ℃ (71.15 ℉). The average number of rainy days in July is 15. The average rainfall is 116.7 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 14:01 (hours and minutes), in the middle of the month 13:53 and at the end of the month 13:37.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in August is this: The average highest temperature in Southwest in August is 21.4 ℃ (70.52 ℉). The average lowest temperature is 9.4 ℃ (48.92 ℉). At the beginning of August you can expect higher temperatures, the average highest temperature is around 21.75 ℃ (71.15 ℉). At the end of August you can expect lower temperatures, the average highest temperature is around 20.9 ℃ (69.62 ℉). The average number of rainy days in August is 15.6. The average rainfall is 123.9 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 13:37 (hours and minutes), in the middle of the month 13:16 and at the end of the month 12:52.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in September is this: The average highest temperature in Southwest in September is 20.4 ℃ (68.72 ℉). The average lowest temperature is 7.6 ℃ (45.68 ℉). At the beginning of September you can expect higher temperatures, the average highest temperature is around 20.9 ℃ (69.62 ℉). At the end of September you can expect lower temperatures, the average highest temperature is around 18.25 ℃ (64.85 ℉). The average number of rainy days in September is 9.9. The average rainfall is 59.2 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:52 (hours and minutes), in the middle of the month 12:26 and at the end of the month 11:59.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in October is this: The average highest temperature in Southwest in October is 16.1 ℃ (60.98 ℉). The average lowest temperature is 1.5 ℃ (34.7 ℉). At the beginning of October you can expect higher temperatures, the average highest temperature is around 18.25 ℃ (64.85 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 13.7 ℃ (56.66 ℉). The average number of rainy days in October is 2.3. The average rainfall is 10.3 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:59 (hours and minutes), in the middle of the month 11:33 and at the end of the month 11:08.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in November is this: The average highest temperature in Southwest in November is 11.3 ℃ (52.34 ℉). The average lowest temperature is -4.8 ℃ (23.36 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 13.7 ℃ (56.66 ℉). At the end of November you can expect lower temperatures, the average highest temperature is around 9.5 ℃ (49.1 ℉). The average number of rainy days in November is 0.4. The average rainfall is 1.7 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:08 (hours and minutes), in the middle of the month 10:45 and at the end of the month 10:27.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Southwest in December is this: The average highest temperature in Southwest in December is 7.7 ℃ (45.86 ℉). The average lowest temperature is -8.8 ℃ (16.16 ℉). At the beginning of December you can expect higher temperatures, the average highest temperature is around 9.5 ℃ (49.1 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 7.45 ℃ (45.41 ℉). The average number of rainy days in December is 0.2. The average rainfall is 1 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 10:27 (hours and minutes), in the middle of the month 10:16 and at the end of the month 10:14.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.| Lhasa | temperature: - | highest temperature: 7.7 ℃ (45.86 ℉) | lowest temperature: -8.8 ℃ (16.16 ℉) | rainfall: 1mm | rainy days: 0.2 |
| Kunming | temperature: 7.9 ℃ (46.22 ℉) | highest temperature: 15.2 ℃ (59.36 ℉) | lowest temperature: 2.7 ℃ (36.86 ℉) | rainfall: 13.7mm | rainy days: 2.4 |
| Guiyang | temperature: - | highest temperature: 11.8 ℃ (53.24 ℉) | lowest temperature: 4.6 ℃ (40.28 ℉) | rainfall: 22.3mm | rainy days: 10.7 |
| Nanning | temperature: - | highest temperature: 19.9 ℃ (67.82 ℉) | lowest temperature: 11.2 ℃ (52.16 ℉) | rainfall: 22.8mm | rainy days: 7.1 |
| Guilin | temperature: - | highest temperature: 14.7 ℃ (58.46 ℉) | lowest temperature: 7 ℃ (44.6 ℉) | rainfall: 46.6mm | rainy days: 10 |
| Dali | temperature: - | highest temperature: 16 ℃ (60.8 ℉) | lowest temperature: 3 ℃ (37.4 ℉) | rainfall: 10.7mm | rainy days: 2.6 |
| Liuzhou | temperature: - | highest temperature: 17.6 ℃ (63.68 ℉) | lowest temperature: -0.3 ℃ (31.46 ℉) | rainfall: 34.3mm | rainy days: 7.2 |
| Zunyi | temperature: - | highest temperature: 10.4 ℃ (50.72 ℉) | lowest temperature: 4.5 ℃ (40.1 ℉) | rainfall: 20.6mm | rainy days: 11.6 |