40°C Hanoi Heat: When Will Refreshing Rains Arrive?

According to the National Center for Hydro-Meteorological Forecasting, on May 26, 2026, Hanoi continued to experience a widespread heatwave driven by a western hot low-pressure system combined with the Foehn wind effect. Outdoor temperatures generally ranged from 38 to 40°C, with some areas climbing past the 40°C mark. Notably, due to dense urban environments packed with concrete and heat-absorbing road surfaces, the real-feel temperature on many streets reached as high as 42 – 43°C. The dry, scorching air persisting from morning till night easily leaves the body prone to fatigue, dehydration, and exhaustion if outdoors for too long. Additionally, the UV index during the day remained extremely high, ranging from 10 to 13, posing potential risks to skin and eyes upon direct sun exposure.

Hanoi Weather Forecast: When Will Relief Rains Arrive?

According to weather forecasts, this severe heatwave is expected to ease in the coming days.

• May 27: Hanoi will maintain high temperatures, though localized thunderstorms may develop in some areas by late afternoon or evening.

• From May 28: The Northern region is projected to welcome widespread thunderstorms, significantly dropping temperatures below 35°C and bringing cooler, more pleasant weather.

Note: During this hot-to-rainy transitional phase, residents should stay alert for potential thunderstorms, tornadoes, lightning, and strong gusts in the late afternoon.

Measures to Prevent Heatstroke and Protect Your Health

To safely navigate these furnace-like days, medical experts recommend the following key precautions:

• Limit outdoor activities during peak hours: The period from 11:00 AM to 4:00 PM sees the strongest thermal radiation. If traveling outdoors is unavoidable, ensure thorough protection with sun jackets, sunglasses, and thick masks.

• Adjust air conditioning temperatures wisely: Avoid setting the air conditioner too low (below 25°C) to prevent thermal shock when stepping from a cold room into the outdoor heat.

• Proactively stay hydrated: As the body constantly sweats, the loss of water and minerals happens rapidly. Do not wait until you are deeply thirsty to drink. Instead, maintain the habit of taking small sips regularly throughout the day.

Alongside fruit juices or soups during meals, actively replenishing with pure water is the fastest way for the body to regain its balance. Many families and office workers in the capital these days prioritize bottled water sourced from nature for hydration. Among these, AVIA 3A Bottled Water is a familiar choice, thanks to its naturally refreshing sweetness akin to early-season rainwater. The product gently cools down the body, delivering a soothing sensation and effectively replenishing energy during sweltering days.

Proactively protect your health and that of your family, and listen to your body to ensure a safe, healthy summer!