Do you need to know, when is the best time to go to Bangladesh? Then you should take a look here, what weather you can expect there during the year.
The climate of Bangladesh is tropical. There are usually mild winters and hot, humid summers. You can also expect humid, warm rainy monsoon from June to October. Around 80% of the rainfall in Bangladesh occurs during the monsoon season.
When speaking about the usual weather in this state, the information is relevant for example for these popular places: Bagerhat, Bandarban District, Bandarban Town, Barisal, Barisal Division, Benapole, Bogra, Chandpur, Char Atra, Chittagong, Chittagong Division, Chittagong Hill Tracts, Comilla, Cox's Bazar, Dhaka, Dhaka Division, Gaud, Gopalgonj, Haor Basin, Jaipurhat District, Jessore, Khagrachhari, Khulna, Khulna Division, Kuakata, Mymensingh, Mymensingh Division, Naogaon District, Natore District, Nawabganj District, Nijhum Dwip, Pabna, Pabna District, Puthia, Rajshahi, Rajshahi District, Rajshahi Division, Rangamati, Rangpur Division, Saidpur, Saint Martins Island, Sirajganj District, Sonargaon, Sundarbans, Sylhet, Sylhet Division, Tangail, Teknaf.
Let's look now what weather you can expect in the area around the capital and in many other cities. The warmest month here is May, the average maximum temperature is 33.8 ℃ (92.84 ℉). The average minimum temperature in this month is 25 ℃ (77 ℉). The coldest month here is January, the average maximum temperature is 25 ℃ (77 ℉). The average minimum temperature in this month is 12.8 ℃ (55.04 ℉). The most rainy month here is August, the average number of rainy days is 21.5. The least rainy month here is December, the average number of rainy days is 0. 
When travelling to some places in Bangladesh, always consider the altitude of the the place as well. The highest point here is Keokradong (1230 m) and the lowest point is Indian Ocean (0 m). So the differences in altitudes in this country are not negligible and you should expect the weather to be different in places in different altitudes. 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 Bangladesh in January is this: The average highest temperature in Bangladesh in January is 25 ℃ (77 ℉). The average lowest temperature is 12.8 ℃ (55.04 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 25.8 ℃ (78.44 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 26.8 ℃ (80.24 ℉). The average number of rainy days in January is 1. The average rainfall is 7.1 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 10:41 (hours and minutes), in the middle of the month 10:49 and at the end of the month 11:03.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 Bangladesh in February is this: The average highest temperature in Bangladesh in February is 28.6 ℃ (83.48 ℉). The average lowest temperature is 15.4 ℃ (59.72 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 26.8 ℃ (80.24 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 30.4 ℃ (86.72 ℉). The average number of rainy days in February is 3. The average rainfall is 25.6 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 11:03 (hours and minutes), in the middle of the month 11:21 and at the end of the month 11:40.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 Bangladesh in March is this: The average highest temperature in Bangladesh in March is 32.2 ℃ (89.96 ℉). The average lowest temperature is 20.2 ℃ (68.36 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 30.4 ℃ (86.72 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 32.85 ℃ (91.13 ℉). The average number of rainy days in March is 3.1. The average rainfall is 63.5 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 11:40 (hours and minutes), in the middle of the month 12:01 and at the end of the month 12:22.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 Bangladesh in April is this: The average highest temperature in Bangladesh in April is 33.5 ℃ (92.3 ℉). The average lowest temperature is 23.2 ℃ (73.76 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 32.85 ℃ (91.13 ℉). At the end of April you can expect higher temperatures, the average highest temperature is around 33.65 ℃ (92.57 ℉). The average number of rainy days in April is 8. The average rainfall is 155 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 12:22 (hours and minutes), in the middle of the month 12:42 and at the end of the month 13:01.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 Bangladesh in May is this: The average highest temperature in Bangladesh in May is 33.8 ℃ (92.84 ℉). The average lowest temperature is 25 ℃ (77 ℉). At the beginning of May you can expect lower temperatures, the average highest temperature is around 33.65 ℃ (92.57 ℉). At the end of May you can expect lower temperatures, the average highest temperature is around 33.25 ℃ (91.85 ℉). The average number of rainy days in May is 14.7. The average rainfall is 336.4 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 13:01 (hours and minutes), in the middle of the month 13:17 and at the end of the month 13:28.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 Bangladesh in June is this: The average highest temperature in Bangladesh in June is 32.7 ℃ (90.86 ℉). The average lowest temperature is 26.5 ℃ (79.7 ℉). At the beginning of June you can expect higher temperatures, the average highest temperature is around 33.25 ℃ (91.85 ℉). At the end of June you can expect lower temperatures, the average highest temperature is around 31.9 ℃ (89.42 ℉). The average number of rainy days in June is 18. The average rainfall is 336.5 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 13:28 (hours and minutes), in the middle of the month 13:35 and at the end of the month 13:35.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 Bangladesh in July is this: The average highest temperature in Bangladesh in July is 31.1 ℃ (87.98 ℉). The average lowest temperature is 26.6 ℃ (79.88 ℉). At the beginning of July you can expect higher temperatures, the average highest temperature is around 31.9 ℃ (89.42 ℉). At the end of July you can expect higher temperatures, the average highest temperature is around 31.3 ℃ (88.34 ℉). The average number of rainy days in July is 20.7. The average rainfall is 370.2 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 13:35 (hours and minutes), in the middle of the month 13:28 and at the end of the month 13:16.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 Bangladesh in August is this: The average highest temperature in Bangladesh in August is 31.5 ℃ (88.7 ℉). The average lowest temperature is 26.3 ℃ (79.34 ℉). At the beginning of August you can expect lower temperatures, the average highest temperature is around 31.3 ℃ (88.34 ℉). At the end of August you can expect higher temperatures, the average highest temperature is around 32 ℃ (89.6 ℉). The average number of rainy days in August is 21.5. The average rainfall is 316.6 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 13:16 (hours and minutes), in the middle of the month 13:00 and at the end of the month 12:41.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 Bangladesh in September is this: The average highest temperature in Bangladesh in September is 32.5 ℃ (90.5 ℉). The average lowest temperature is 26.5 ℃ (79.7 ℉). At the beginning of September you can expect lower temperatures, the average highest temperature is around 32 ℃ (89.6 ℉). At the end of September you can expect lower temperatures, the average highest temperature is around 32.05 ℃ (89.69 ℉). The average number of rainy days in September is 15.8. The average rainfall is 306.2 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 12:41 (hours and minutes), in the middle of the month 12:21 and at the end of the month 12:01.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 Bangladesh in October is this: The average highest temperature in Bangladesh in October is 31.6 ℃ (88.88 ℉). The average lowest temperature is 23.9 ℃ (75.02 ℉). At the beginning of October you can expect higher temperatures, the average highest temperature is around 32.05 ℃ (89.69 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 30.35 ℃ (86.63 ℉). The average number of rainy days in October is 8.2. The average rainfall is 176.9 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 12:01 (hours and minutes), in the middle of the month 11:40 and at the end of the month 11:21.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 Bangladesh in November is this: The average highest temperature in Bangladesh in November is 29.1 ℃ (84.38 ℉). The average lowest temperature is 19.8 ℃ (67.64 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 30.35 ℃ (86.63 ℉). At the end of November you can expect lower temperatures, the average highest temperature is around 27.85 ℃ (82.13 ℉). The average number of rainy days in November is 1. The average rainfall is 33.4 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 11:21 (hours and minutes), in the middle of the month 11:04 and at the end of the month 10:50.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 Bangladesh in December is this: The average highest temperature in Bangladesh in December is 26.6 ℃ (79.88 ℉). The average lowest temperature is 14.6 ℃ (58.28 ℉). At the beginning of December you can expect higher temperatures, the average highest temperature is around 27.85 ℃ (82.13 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 25.8 ℃ (78.44 ℉). The average number of rainy days in December is 0. The average rainfall is 15 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 10:50 (hours and minutes), in the middle of the month 10:41 and at the end of the month 10:40.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.| Dhaka | temperature: - | highest temperature: 26.6 ℃ (79.88 ℉) | lowest temperature: 14.6 ℃ (58.28 ℉) | rainfall: 15mm | rainy days: 0 |
| Chittagong | temperature: - | highest temperature: 26.9 ℃ (80.42 ℉) | lowest temperature: 16.1 ℃ (60.98 ℉) | rainfall: 13.1mm | rainy days: 0 |
| Sylhet | temperature: - | highest temperature: 26 ℃ (78.8 ℉) | lowest temperature: 13.8 ℃ (56.84 ℉) | rainfall: 13.1mm | rainy days: 0 |
| Rajshahi | temperature: - | highest temperature: 26.4 ℃ (79.52 ℉) | lowest temperature: 12.6 ℃ (54.68 ℉) | rainfall: 11.7mm | rainy days: 0 |
| Khulna | temperature: - | highest temperature: 27.1 ℃ (80.78 ℉) | lowest temperature: 14.2 ℃ (57.56 ℉) | rainfall: 8mm | rainy days: 0 |
| Barishal | temperature: - | highest temperature: 27.2 ℃ (80.96 ℉) | lowest temperature: 13.3 ℃ (55.94 ℉) | rainfall: 14.9mm | rainy days: 0 |