Weather in Chattogram

May is the warmest month (average 29.1°C, high 31.9°C) and January is the coolest (average 18.9°C, low 13.5°C). That 10.2°C swing in monthly averages is the first thing to plan around in Chattogram.

Rain is the monsoon runs from April to October, inside an annual total of 3061 mm. The wettest month is July at 782 mm; the driest is January at 9 mm. Chattogram is in Bangladesh at 22.3°N. The 2001–2020 NASA POWER daily record describes a monsoon climate with a sharp wet-dry split. On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are December, January, and February.

Best months to visit Chattogram

The three months with the highest comfort score are December, January, and February: December (20.1°C average, 14 mm, 78% humidity); January (18.9°C average, 9 mm, 71% humidity); February (22.2°C average, 19 mm, 63% humidity). Those months sit across the year end, so they are listed in season order rather than January-to-December. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the monsoon itself — fewer crowds, greener landscape, heavier rain — aim at April–October instead of the score.

Temperature through the year

The heat peaks in May, when the typical afternoon is 31.9°C. The opposite pole is January, when mornings average 13.5°C.

Mean high across all twelve months is 29.4°C and mean low is 22.2°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

Monsoon and dry months

The monsoon in Chattogram starts in April and ends in October (April, May, June, July, August, September, and October). July is the core of it at 782 mm. January is the other extreme, with 9 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. July averages 29 such days; January averages 1.

The calendar in Chattogram

January is the coolest month, with lows around 13.5°C and highs near 24.4°C. Rainfall is 9 mm. February brings 19 mm and 2 rainy days; temperatures run from 16.5°C to 27.9°C. March stands apart from the months beside it: 31.8°C / 21.1°C and 41 mm. The monsoon opens in April. Expect 126 mm and 11 rainy days, with nights around 24.8°C. May is the warmest month. Afternoon highs average 31.9°C and nights settle near 26.2°C, with 305 mm of rain. June brings 551 mm and 26 rainy days; temperatures run from 26.6°C to 30.7°C.

July is the wettest month — 782 mm and 29 rainy days, with 89% humidity. August: 30.2°C high, 26.0°C low, 531 mm rain, 89% humidity. In September, Chattogram averages 30.2°C by day and 25.9°C at night, with 395 mm of rain. October closes the monsoon: 233 mm over 16 rainy days, then the calendar dries. November: 27.9°C high, 19.7°C low, 56 mm rain, 79% humidity. December stands apart from the months beside it: 24.9°C / 15.4°C and 14 mm.

How Chattogram compares inside Bangladesh

Dhaka is about 211 km away: Chattogram is 0.9°C cooler than Dhaka in its hottest month and 836 mm wetter over the year than Dhaka. Dhaka’s wettest month is July (437 mm) versus July here.

Gazipur is about 234 km away: Chattogram is 0.8°C cooler than Gazipur in its hottest month and 880 mm wetter over the year than Gazipur. Gazipur’s wettest month is July (404 mm) versus July here.

Khulna is about 239 km away: Chattogram is 2.5°C cooler than Khulna in its hottest month and 1286 mm wetter over the year than Khulna. Khulna’s wettest month is July (374 mm) versus July here.