Dhaka, Dhaka Division, Bangladesh
Dhaka is in hardiness zone 11b
USDA-equivalent zone
11b
Winter minima between 7.2°C (45°F)45°F (7.2°C) and 10°C (50°F)50°F (10°C).
Mean annual coldest night
8.5°C (47.2°F)47.2°F (8.5°C)
Averaged across the record. This is the figure the zone is calculated from.
Coldest night on record
4.4°C (39.9°F)39.9°F (4.4°C)
A single night, not a planning figure — but it is what an unlucky winter can do.
What the zone tells you
A hardiness zone answers exactly one question: how cold does it get here in an average winter, at worst. It is calculated from the mean annual extreme minimum — the coldest night of each year, averaged over the record. For Dhaka that figure is 8.5°C (47.2°F)47.2°F (8.5°C), which places it in zone 11b.
Compare this figure with the cold-hardiness range of the exact cultivar you plan to buy. A compatible rating is a useful first screen, but does not guarantee survival: drainage, exposure, plant age and the duration of cold also matter. Roots in containers may need more protection than roots in the ground. Ask the supplier about local experience with the same cultivar.
What it does not tell you
It says nothing about when to plant. Two places can share a zone and have growing seasons that differ by six weeks, because a zone is a single winter night and a season is the gap between the last frost of spring and the first of autumn. A maritime climate and a continental one can sit in the same zone and behave nothing alike.
It also says nothing about heat, drought, humidity or the length of your summer, all of which can matter more than winter cold. A zone number is a floor, not a description of a climate.
Zone 11b elsewhere
Other places in the same zone
Same winter minimum, often a very different growing season. Compare the frost dates on these tiles against Dhaka and the limits of the zone system become obvious.
Seasonal context
Rainfall and the growing season in Dhaka
July has the highest average precipitation (437 mm); January has the lowest (9 mm). Compare this pattern with the planting windows and your water supply.
During wetter months, check that beds and containers drain after heavy rain. During drier months, plan how you will keep seeds and new transplants watered. Monthly averages can hide long dry spells and intense storms; they do not show soil moisture, humidity or this week's weather.
Frost-free does not mean every month is suitable. In tropical and monsoon climates, rainfall, heat, drainage and the cultivar can set the practical growing season. Match the temperature window to these conditions and check advice from a local grower before buying planting material.
Source: NASA POWER, corrected MERRA-2 precipitation, 2001–2020. Values are approximate monthly totals, including the water equivalent of snow, from the nearest 0.5° × 0.625° grid cell. This reference period differs from the temperature record. Rainfall provides context and does not change the calculated planting dates. Method and limitations.