Climate Insights for Sylhet

The climate in Sylhet is hot. The average annual temperature is 25°C and approximately 3567mm of precipitation falls per year. June is the wettest month, receiving around 608mm of rainfall. Sylhet is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: September, August, July. The coldest months are January, December, February, when temperatures can drop to 14°C.

Sylhet sees moderate temperature variation throughout the year, ranging from 14°C to 33°C. The warmest month is September, when average highs reach 33°C and the mean temperature sits around 29°C. January is the coolest month, with minimum temperatures around 14°C and an average of 18°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs. The sharpest temperature change occurs between November and December, with a 4°C shift in average temperatures.

Sylhet is a very wet location, receiving approximately 3567mm of precipitation annually, which averages out to around 297mm per month. The wettest month is June, averaging 608mm of rainfall. July and August also tend to see above-average precipitation. The driest month is January, with just 14mm. That's 594mm less than June, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Sylhet is relatively calm, with an average annual wind speed of 9km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is March, averaging 10km/h, though still comfortable for most outdoor activities. The calmest conditions occur in October, with average winds dropping to 8km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 2km/h between the calmest and windiest months.

It is currently spring in Sylhet, which began on March 20, 2026. Sylhet is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in September at around 33°C, while the coldest stretch bottoms out in January near 14°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Sylhet is during January, February, November and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 32mm per month. By contrast, September can be uncomfortably hot with temperatures reaching 33°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Sylhet based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.