Climate and monthly weather forecastSylhet, Bangladesh
Climate and monthly weather forecast
The climate of Sylhet
Situated in Bangladesh, Sylhet falls under the Am category of the Köppen climate classification. This system designates it a tropical monsoon climate. The climate manifests with high temperatures throughout the year, coupled with significant seasonal rainfall variations.Shifting focus to the weather parameters, it is observed that the maximum temperatures range from 25.5°C (77.9°F) to 34.4°C (93.9°F). On the other hand, minimum temperatures fluctuate between 12°C (53.6°F) to 25.3°C (77.5°F). Consistent with a tropical monsoon climate, Sylhet experiences high humidity levels, peaking at 89% and dipping at 55%.
The tropical city receives rainfall most abundantly from May to August, while November to April sees almost negligible precipitation. Annual rainfall varies hugely from a small 4mm (0.16") in February to a substantial 353mm (13.9") in June. The length of daylight throughout the year stretches from 10.6 hours in December to 13.7 hours in June, again showcasing the distinct tropical trait. Wind speeds over the year display a less dramatic fluctuation, hovering between 4.3km/h (2.7mph) to a maximum of just over 7.7km/h (4.8mph).
Traditionally, Sylhet exhibits the distinctive monsoon patterns, with a significant surge in rainfall from May leading to June's peak, followed by a gradual tapering till November. The sunniest months are in winter, with December giving approximately 27.6 sunny days.
The best time to visit Sylhet
For potential visitors to Sylhet, the best time to visit is from November to February. The temperatures during these months are relatively milder, ranging from 25.5°C (77.9°F) to 28.3°C (82.9°F), and the average rainfall is the lowest in the year, making outdoor activities more enjoyable. Moreover, the chances of sunny days are higher during these months, which increases the overall appeal of Sylhet as a tourist destination.The worst time to visit Sylhet
Conversely, the period from May to August is not recommended for visiting Sylhet. During these months, the city experiences the highest rainfalls of the year, often reaching 353mm (13.9") in June. This time also coincides with the highest humidity levels, hitting a high of 89%, and temperatures soar up to 34.4°C (93.9°F) further adversely impacting the comfort of potential visitors.Spring weather in Sylhet
The spring weather in Sylhet, from March to May, brings warmth and humidity. Temperatures start to rise, reaching up to 33.1°C (91.6°F) in May. Rainfall begins to increase from March, with April witnessing a significant jump in precipitation reaching 175mm (6.89"). Consequently, the humidity starts to rise, climbing up from 55% in March to 79% in May.Summer weather in Sylhet
Summer, from June to August, is the monsoon season in Sylhet. Temperatures during this period are at their peak, hitting a high of 34.4°C (93.9°F) in June; humidity too is at very high levels. Significant rainstorms occur frequently, with July receiving around 287mm (11.3") of rainfall.Autumn weather in Sylhet
Autumn, from September to November, sees a decrease in temperature with November registering a lower of 28.3°C (82.9°F). While rainfall begins to subside in autumn occurring over an average of 2.4 days. Compared to the following months, January promises a relatively dry and cooler climate.Welcoming January, Sylhet notes an average high-temperature of a still moderately hot 25.6°C (78.1°F), nearly consistent with December's 25.5°C (77.9°F). In stark contrast to the day's heat, the temperature in Sylhet dips to an average of 12°C (53.6°F) during January nights. In January, the average relative humidity is 66%. January is the month with the least rainfall. Rain falls for 2.4 days and accumulates 4mm (0.16") of precipitation. The average length of the day in January is 10h and 47min.
On the first day of the month, sunrise is at 6:37 am and sunset at 5:14 pm. On the last day of January, in Sylhet, sunrise is at 6:35 am and sunset at 5:36 pm +06. The average sunshine in January in Sylhet, Bangladesh, is 7.6h. The months with the lowest UV index are January and December, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The daily high UV index of 5 during January translates into the following recommendations:
Be vigilant - Preventing sunburn is recommended. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Weather in February
February ushers in a gradual increase in temperatures and humidity levels in Sylhet. As winter dissipates, longer sunlight hours and slightly warmer day temperatures become common, preparing the land for the showers of the impending monsoon. Weather in February »Weather in March
In Sylhet, March marks the start of pre-monsoon summertime, characterized by higher temperatures and sporadic rainfall. The days become longer, and the humidity starts to pick up, reaching up to 55% relative humidity. This month witnesses a substantial leap in rainfall, with volumes reaching up to 49mm (1.93") over 11.3 days. Weather in March »Weather in April
April, serving as a precursor to the rainy season, features a stark shift in Sylhet's weather. It's distinguished by the steep increase in rainfall, reaching 175mm (6.89") dispersed over 21.3 days, representing the onset of the much-anticipated monsoon. Weather in April »Weather in May
May in Sylhet brings the peak of pre-monsoon conditions and the arrival of the southwest monsoon. Unlike the preceding months, the maximum temperature begins to stabilize, and the overall weather becomes more humid. The month is noteworthy for its significant increase in rainfall with volumes peaking at 289mm (11.38") over 26.8 days. Weather in May »Weather in June
June marks the full arrival of the monsoon season in Sylhet, Bangladesh. The month is characterized by continual rain showers, heavy cloud cover, and consistent high temperatures, indicating the height of the monsoon. This month reaches the height of humidity at 86%, and it's observed that maximum rainfall of 353mm (13.9") occurs in June. Weather in June »Weather in July
July continues where June leaves off, with monsoon conditions persisting in Sylhet. The weather is dominated by high humidity and rainfall, although temperatures remain relatively constant throughout the month. Rainfall levels drop slightly to 287mm (11.3"), but rainy days still dominate the month. Weather in July »Weather in August
August sustains the monsoon momentum in Sylhet as one of the peak rainy months. Conditions remain consistent with those of the previous month, showcasing high temperatures, intensive rainfall, and high humidity levels. Despite a deplete in rain volumes to 308mm (12.13"), the month still receives extensive showers over 30.2 days. Weather in August »Weather in September
Entering September, the city of Sylhet experiences a slow yet discernible shift from the monsoon season. The monsoon effects remain, but temperatures and rainfall start to decline, marking the onset of post-monsoon conditions. Weather in September »Weather in October
October brings forth a significant reduction in rainfall in Sylhet, indicating the retreat of the monsoon. Following the weather transitions in September, this change gears the weather patterns towards drier, clearer skies. The dispersion in rainfall drops considerably to 111mm (4.37"), taking place over only 18.3 days. Weather in October »Weather in November
In Sylhet, November witnesses the continuation of dry weather and the beginning of the cool season. Following from the transition in October, this month sees a significant drop in rainfall and an increase in sunlight hours. The sharp decline in rainfall volumes, all the way down to 18mm (0.71") over 4.8 days, underlines the shift to the dry season. Weather in November »Weather in December
December, being the final month of the year in Sylhet, ends the dry season and gives way to winter. The weather is substantially cooler with clear skies, low relative humidity, and minimal rainfall, making December distinct from the rest of the year. Weather in December »Updated: Jan 30, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The month with the least rainfall in Sylhet is January, when the rain falls for 2.4 days and typically collects 4mm (0.16") of precipitation.
In Sylhet, Bangladesh, during the entire year, the rain falls for 208.1 days and collects up to 1868mm (73.54") of precipitation.
January and December, with an average maximum UV index of 5, are months with the lowest UV index.
The least humid month is March, with an average relative humidity of 55%.
With an average high-temperature of 34.4°C (93.9°F) and an average low-temperature of 22.8°C (73°F), April is the warmest month in Sylhet.
The month with the most sunshine in Sylhet, Bangladesh, is April, with an average of 10.5h of sunshine.
The months with the highest UV index are April and September, with an average maximum UV index of 7.
The month with the most rainfall is June, when the rain falls for 29.3 days and typically aggregates up to 353mm (13.9") of precipitation.
The month with the longest days in Sylhet is June, with an average of 13h and 42min of daylight.
The most humid month is July, with an average relative humidity of 89%.
With an average of 6.9h of sunshine, July has the least sunshine of the year.
December proves to be the coldest month, recording an average maximum temperature of 25.5°C (77.9°F) and a minimum temperature of 13.5°C (56.3°F).
The month with the shortest days is December, with an average of 10h and 36min of daylight.
Sylhet does not observe Daylight Saving Time (DST). +06 timezone is used over the entire year.
Average temperature
Sylhet, Bangladesh
The warmest month (with the highest average high temperature) is April (34.4°C).
The month with the lowest average high temperature is December (25.5°C).
The month with the highest average low temperature is June (25.3°C).
The coldest month (with the lowest average low temperature) is January (12°C).
Average pressure
Sylhet, Bangladesh
- Average pressure in January:
1014.9mbar - Average pressure in February:
1013.4mbar - Average pressure in March:
1010.9mbar - Average pressure in April:
1008.6mbar - Average pressure in May:
1005.9mbar - Average pressure in June:
1002.3mbar
- Average pressure in July:
1002mbar - Average pressure in August:
1003.3mbar - Average pressure in September:
1006.1mbar - Average pressure in October:
1009.9mbar - Average pressure in November:
1012.7mbar - Average pressure in December:
1014.2mbar
The month with the highest atmospheric pressure is January (1014.9mbar).
The month with the lowest atmospheric pressure is July (1002mbar).
Average wind speed
Sylhet, Bangladesh
- Average wind speed in January:
4.6km/h - Average wind speed in February:
5.2km/h - Average wind speed in March:
6.1km/h - Average wind speed in April:
6.4km/h - Average wind speed in May:
6.3km/h - Average wind speed in June:
7.2km/h
- Average wind speed in July:
7.7km/h - Average wind speed in August:
7km/h - Average wind speed in September:
5.9km/h - Average wind speed in October:
4.6km/h - Average wind speed in November:
4.3km/h - Average wind speed in December:
4.3km/h
The windiest month (with the highest average wind speed) is July (7.7km/h).
The calmest months (with the lowest average wind speed) are November and December (4.3km/h).
Average humidity
Sylhet, Bangladesh
The month with the highest relative humidity is July (89%).
The month with the lowest relative humidity is March (55%).
Average rainfall
Sylhet, Bangladesh
- Average rainfall in January:
4mm - Average rainfall in February:
13mm - Average rainfall in March:
49mm - Average rainfall in April:
175mm - Average rainfall in May:
289mm - Average rainfall in June:
353mm
The wettest month (with the highest rainfall) is June (353mm).
The driest month (with the least rainfall) is January (4mm).
Average rainfall days
Sylhet, Bangladesh
- Average rainfall days in January:
2.4 days - Average rainfall days in February:
3.4 days - Average rainfall days in March:
11.3 days - Average rainfall days in April:
21.3 days - Average rainfall days in May:
26.8 days - Average rainfall days in June:
29.3 days
- Average rainfall days in July:
29.3 days - Average rainfall days in August:
30.2 days - Average rainfall days in September:
28.5 days - Average rainfall days in October:
18.3 days - Average rainfall days in November:
4.8 days - Average rainfall days in December:
2.5 days
The month with the highest number of rainy days is August (30.2 days).
The month with the least rainy days is January (2.4 days).
Average daylight / Average sunshine
Sylhet, Bangladesh
- Average daylight in January:
10h and 48min - Average daylight in February:
11h and 18min - Average daylight in March:
12h and 0min - Average daylight in April:
12h and 42min - Average daylight in May:
13h and 24min - Average daylight in June:
13h and 42min
- Average daylight in July:
13h and 30min - Average daylight in August:
13h and 0min - Average daylight in September:
12h and 18min - Average daylight in October:
11h and 36min - Average daylight in November:
10h and 54min - Average daylight in December:
10h and 36min
The month with the longest days is June (Average daylight: 13h and 42min).
The month with the shortest days is December (Average daylight: 10h and 36min).
- Average sunshine in January:
7h and 36min - Average sunshine in February:
7h and 30min - Average sunshine in March:
9h and 36min - Average sunshine in April:
10h and 30min - Average sunshine in May:
9h and 42min - Average sunshine in June:
8h and 12min
- Average sunshine in July:
6h and 54min - Average sunshine in August:
7h and 30min - Average sunshine in September:
7h and 18min - Average sunshine in October:
7h and 54min - Average sunshine in November:
7h and 12min - Average sunshine in December:
7h and 18min
The month with the most sunshine is April (Average sunshine: 10h and 30min).
The month with the least sunshine is July (Average sunshine: 6h and 54min).
Average sunshine days
Sylhet, Bangladesh
- Average sunshine days in January:
27.6 days - Average sunshine days in February:
24.5 days - Average sunshine days in March:
17.6 days - Average sunshine days in April:
6.2 days - Average sunshine days in May:
2.1 days - Average sunshine days in June:
0.4 days
- Average sunshine days in July:
1.3 days - Average sunshine days in August:
0.8 days - Average sunshine days in September:
0.8 days - Average sunshine days in October:
10.4 days - Average sunshine days in November:
23.5 days - Average sunshine days in December:
27.6 days
The months with the most sunshine days are January and December (27.6 days).
The month with the least sunshine days is June (0.4 days).
Average UV index
Sylhet, Bangladesh
The months with the highest UV index are April and September (UV index 7).
The months with the lowest UV index are January and December (UV index 5).
Average cloud cover
Sylhet, Bangladesh
The month with the most cloud cover is July (Cloud cover 62).
The month with the least cloud cover is January (Cloud cover 8).
Average visibility
Sylhet, Bangladesh
The months with the highest visibility are January, February, March and December (10km).
The months with the lowest visibility are July, August and September (7km).
