Hanoi Climate Trends
Vietnam · Asia · 50 years of climate trend data
This page tracks how Hanoi's climate has shifted over fifty years of daily measurements, warmer summers, milder winters, and changes in rainfall, rather than current conditions. For day-to-day and current weather in Hanoi, see theMeteo Capital Cities, or for where this trend points next, see Meteo Future Trends. See how this pace of change ranks against every other world capitalon the Climate Shift Index.Compare its climate trend against all 195 world capitals on the full interactive map.
Data through August 4, 2026.
Frequently asked questions about Hanoi's climate
How much warmer have summers in Hanoi become?
The average daytime high across June, July and August rose by 1.1°C between 1976-1980 and 2021-2025. That is a five-year average at each end rather than two isolated summers, so a single exceptional heatwave or cool summer does not drive the number.
Have winters in Hanoi become milder?
The average daytime high across December, January and February rose by 1°C between 1976-1980 and 2021-2025. In many capitals in this dataset winter is changing faster than summer, which shows up most clearly in the frost-day count below.
How many days above 30°C does Hanoi get a year?
Hanoi averaged 159 days a year above 30°C in 2021-2025, up from 130 in 1976-1980. These are the days that set peak cooling demand and the days hospitals see heat complaints rise.
How many frost days does Hanoi still get?
Hanoi does not drop below freezing in any year of this record, not in 1976-1980 and not in 2021-2025. Frost is not a useful measure of change here, though the heat figures above are.
Is spring arriving earlier in Hanoi?
Spring now starts about 0.1 weeks earlier than in 1976-1980. The start point is the first day the trailing seven-day average high crosses 12°C, a fixed in-house measure used only to compare Hanoi against itself rather than against other cities.
Has the growing season in Hanoi grown longer?
The growing season here is measured as the stretch between the start of spring and the first autumn night below freezing. Hanoi has no reliable autumn frost in this record, so that measure yields no meaningful number.
Is rainfall in Hanoi getting heavier?
Hanoi averaged 35.2 days a year with more than 20mm of rain in 2021-2025, up from 25 in 1976-1980. Warmer air holds more water vapour, so the same annual rainfall increasingly arrives in shorter, harder bursts, which loads drains and water storage more than the annual total suggests.
