Last updated: January 18, 2025
Hanoi, Vietnam, exhibits a Cwa climate classification according to the Köppen-Geiger system, characterized by a distinct seasonal pattern. With a minimum temperature of 7°C (46°F) in January, the winter months bring a notable chill, while the summer peaks at a maximum of 41°C (106°F) in June. The annual average temperature hovers around 25°C (77°F), indicating a warm tropical climate punctuated by a humid subtropical influence. This climatic diversity not only shapes daily life in Hanoi but also plays a pivotal role in its ecosystem and agricultural practices.
Hanoi experiences a dynamic temperature range throughout the year, marked by distinct seasonal variations. Winter months, particularly January and February, bring cooler temperatures, with minimums around 7-8°C (46-47°F) and averages of 18-19°C (65-66°F). As spring arrives in March and April, temperatures gradually rise, hitting maximums of 35°C (94°F) and averaging 25°C (76°F) by late April. The peak of summer is marked by June's scorching temperatures, where averages reach 31°C (87°F) and maximums soar to 41°C (106°F). This heat persists in July and August, albeit slightly moderated, before giving way to cooler conditions in autumn. September and October see a decline, with temperatures averaging 28°C (83°F) and 25°C (77°F), respectively, and winter reappearing by December, which echoes the early year chill with similar minimum temperatures as January. This cyclical pattern underscores Hanoi's humid subtropical climate, characterized by significant seasonal contrasts.
Hanoi, along with its districts Tay Ho and Hoan Kiem, experiences a notable temperature range throughout the year, with January temperatures dropping to a minimum of 8°C (46°F) and peaking at 40°C (105°F) in June. For more detailed monthly temperature insights, you can explore the links for monthly temperatures in Hanoi, monthly temperatures in Tay Ho, and monthly temperatures in Hoan Kiem.
Hanoi's precipitation patterns reveal a distinctive seasonal rhythm, with rainfall peaking during the summer months. In January and February, the city experiences relatively low rainfall, averaging 58 mm (2.3 in) and 42 mm (1.6 in), respectively. As spring transitions into summer, precipitation begins to rise, culminating in April with 144 mm (5.7 in). May marks a significant increase, with rainfall reaching 186 mm (7.3 in), indicating the onset of the wet season.
The monsoon rains are most intense from June to August, with July recording a staggering 274 mm (10.8 in) and August peaking even further at 391 mm (15.4 in), making it the wettest month of the year. September and October also maintain high precipitation levels, with 231 mm (9.1 in) and 274 mm (10.8 in), respectively. Conversely, late autumn and winter see a sharp drop in rainfall, culminating in November and December with 49 mm (1.9 in) and 42 mm (1.7 in), signaling a drier and cooler period. Throughout the year, rainfall days fluctuate, with the highest number occurring in August at 22 days, reflecting the heavy showers typical of the monsoon season.
Hanoi experiences a marked variation in sunshine duration throughout the year, reflecting its distinct seasonal shifts. The year begins with relatively lower sunshine hours in January, totaling 131 hours, which gradually increases as winter gives way to spring. February sees a notable rise to 185 hours, while March and April maintain this upward trend with 155 and 190 hours, respectively. This buildup culminates in May, where sunshine peaks with an impressive 282 hours, heralding the arrival of summer. The transition into this warmer season reveals a consistent trend, with June, July, and August maintaining high sunshine durations at 276, 274, and 259 hours, respectively.
As autumn approaches, sunshine hours gradually recede, with September still enjoying a generous 267 hours before dipping to 234 hours in October. This decline continues into winter, with November and December recording 233 and 214 hours, respectively. Overall, the pattern clearly illustrates that Hanoi's brightest months lie in late spring and summer, providing ample sunlight for both locals and visitors. Conversely, the winter months are marked by shorter days and less sunshine, setting a picturesque yet subdued atmosphere typical of the season.
Hanoi's UV Index reveals significant fluctuations throughout the year, underscoring the city's exposure to solar radiation. The year kicks off with a UV Index of 8 in January, categorized as very high, requiring just 15 minutes of exposure for sunburn to occur. As February rolls in, this intensity escalates, reaching a UV Index of 10. The trend continues its upward trajectory into March and April, with both months registering a UV Index of 12, classified as extreme, which necessitates minimal sun exposure of only 10 minutes to risk sunburn. This peak in UV radiation lays the groundwork for the approaching summer months, where such extreme levels become more consistent.
From May through September, the UV Index remains at its highest level, sustained at 13 and categorized as extreme, prompting the public to limit sun exposure to just 10 minutes. October exhibits a slight decrease to 11, while November sees another drop to 9, categorized again as very high. Finally, December offers some respite with a UV Index of 7, classified as high, allowing for a longer exposure time of 25 minutes before burning occurs. This annual UV pattern serves as a reminder for residents and visitors alike to remain vigilant about sun safety, particularly during the peak summer months when the risk of harm from UV radiation is at its highest.
UV Risk Categories
In Hanoi, daylight duration exhibits a clear seasonal pattern that reflects the transition from winter to summer and back again. The year begins with approximately 10 hours of daylight in January, gradually increasing to 11 hours in February. As spring arrives, both March and April maintain a steady 12 hours of daylight, providing ample light for outdoor activities and cultural events. The length of daylight peaks in May, reaching 13 hours, a trend that continues into June and July, emphasizing the long, sunny days characteristic of Hanoi's summer.
As summer wanes and autumn approaches, daylight duration experiences a gradual decline. August retains 12 hours of daylight, but this drops to 11 hours in both October and November, marking the onset of shorter days. Finally, December mirrors January, closing the year with a return to around 10 hours of daylight. This cyclical pattern not only influences daily life in Hanoi but also contributes to the rich seasonal diversity that defines the city's climate throughout the year.
Co Loa, Vietnam experiences a tropical climate characterized by warm temperatures and significant rainfall throughout the year. January temperatures range from a minimum of 8°C (46°F) to a maximum of 29°C (84°F), while May and June see peak heat with highs reaching 39°C (103°F) and 40°C (105°F). Precipitation is highest in July and August, with August recording up to 378 mm (14.9 in) of rainfall. Despite the rain, the area enjoys substantial sunshine, particularly in May with 280 hours. For more detailed information, visit Co Loa climate.
Ha Dong, Vietnam experiences a humid subtropical climate characterized by hot and rainy summers and mild winters. Temperatures range from a low of 8°C (46°F) in January to highs of 40°C (105°F) in June. The wettest months are July and August, receiving up to 378 mm (14.9 in) of rainfall, while January and February are comparatively drier. Sunshine is abundant, especially in May with 280 hours, contributing to the region's warm climate. For more details, visit Ha Dong climate.
Hai Ba Trung, Vietnam experiences a tropical climate with significant seasonal variation in temperature and precipitation. The average temperatures range from a mild 18°C (65°F) in January to a hot 31°C (87°F) in May, with peaks reaching up to 40°C (105°F) in June. Rainfall is abundant, particularly from May to August, where July alone sees around 260 mm (10.2 in) of precipitation. Sunshine hours are impressive during the summer months, peaking at 280 hours in May. For more details, visit Hai BaTrung climate.
Hanoi, Vietnam experiences a diverse climate marked by distinct seasonal changes. Winters (December to February) are cooler, with temperatures ranging from 8°C to 19°C (46°F to 66°F) and low precipitation. The summer months (May to August) bring high temperatures, reaching up to 40°C (105°F), along with significant rainfall, especially in July and August, when precipitation can exceed 378 mm (14.9 in). The city enjoys the most sunshine in late spring and early summer, with May boasting around 280 hours of sunlight. For more details, visit Hanoi climate.
Hoan Kiem, Vietnam experiences a diverse climate throughout the year, with temperatures ranging from a minimum of 8°C (46°F) in January to a maximum of 40°C (105°F) in June. The region sees its highest rainfall in August, averaging 378 mm (14.9 in), while the driest months are January and February, with just 58 mm (2.3 in) and 41 mm (1.6 in) respectively. Sunshine is abundant, particularly in May with 280 hours, contributing to a tropical atmosphere. For more detailed information about the climate, consider visiting Hoan Kiem climate.
The climate in Tay Ho, Vietnam, varies significantly throughout the year, characterized by a humid subtropical climate. January and February see cooler temperatures ranging from 8°C to 9°C minimum, while the summer months from May to August experience highs peaking at around 39°C to 40°C. Rainfall is heaviest in July and August, with over 260 mm in July alone, while the dry season brings minimal precipitation in January and December. Sunshine is abundant, particularly in May and June, with around 280 hours of sun. For more detailed information, visit Tay Ho climate.
In conclusion, Hanoi's climate presents a fascinating tapestry of seasonal variations that influence its temperature, precipitation, UV index, sunshine duration, and daylight hours. The city's distinct shift from cooler winters to sweltering summers, coupled with high UV exposure during the peak months, necessitates awareness and preparedness for both residents and visitors alike. As perceptions of daylight evolve throughout the year, the balance between sunlight and rainfall creates unique opportunities for cultural and agricultural activities. Understanding these climatic dynamics is essential for appreciating Hanoi's vibrant environment and for making informed decisions related to health, outdoor pursuits, and urban planning.