Heat Index Report: The Most Dangerous Travel Destinations for Summer 2024

If you’re not a fan of the sun, these cities might find their way onto your 'do-not-visit' list.

According to the latest global warming statistics, 2024 is on track to be the world’s warmest year on record.

Nowadays, some places experience extreme heat not as an anomaly but as a regular event.

From tropical megacities to arid desert civilizations, we've identified over 40 popular travel destinations where scorching temperatures are a routine part of life.

It’s crucial to note that heat danger varies among individuals. Vulnerable populations, such as the elderly, children, and those with preexisting health conditions, are more susceptible to being at risk in high-temperature environments.

Methodology

To identify the hottest travel destinations, we extracted historical temperature and humidity levels for the summer of 2023 in over 40 cities and created a heat index.

The heat index represents what the temperature feels like to the human body when relative humidity is combined with the air temperature.

We categorized days into three levels of heat danger based on the heat index and assigned weights to each category to reflect its severity.

• Extreme caution days: 90–102°F (32.2–38.9°C). These days pose significant health risks, especially for vulnerable populations. We assigned a weight of 1 to these days.
• Danger days: 103–124°F (39.4–51.1°C). These days present a higher level of risk and can potentially cause heat-related illnesses more quickly. They were given a weight of 2.
• Extreme danger days: ≥125°F (≥51.6°C). These days are the most hazardous, with a high likelihood of causing severe heat-related illnesses or even fatalities. We assigned the highest weight of 3 to these days.

The formula used to calculate the score for each city is:

This scoring system allowed us to rank the cities from most to least dangerous in terms of high heat during the summer.

10 sizzling cities to avoid this summer

The analysis shows that the Middle East is the most hazardous region regarding extreme heat, with cities like Dubai, Doha, and Kuwait City experiencing the most dangerous conditions.

Last summer, temperatures exceeded 50°C (122°F) in the United Arab Emirates for the first time.

#1 Dubai, United Arab Emirates

Dubai, or the ‘City of Gold,’ has a hot desert climate with extremely high temperatures and minimal yearly rainfall.

In the summer of 2023, 8.7% of days fell into the extreme caution category, 89.1% were in the danger category, and 1.1% were in the extreme danger category.

Nevertheless, Dubai attracts millions of tourists annually with its ultra-modern architecture, luxury shopping, and vibrant nightlife. The city has a network of air-conditioned bus shelters to protect residents and tourists from the intense heat.

#2 Doha, Qatar

Doha experiences a scorching desert climate with very high temperatures and humidity.

During the summer of 2023, 34.8% of days were classified as extreme caution, 57.6% as danger, and 3.3% as extreme danger.

An interesting fact about Doha is that it hosted the 2022 FIFA World Cup, marking the first time the tournament was held in the Middle East and during the winter season to avoid the extreme summer heat.

#3 Chennai, India

Chennai has a tropical wet and dry climate with hot and humid conditions year-round.

In the summer of 2023, 58.7% of days were categorized as extreme caution and 28.3% as danger.

Chennai regularly experiences sea breezes from the Bay of Bengal in the afternoons, which provide a slight respite from the intense heat.

#4 New Delhi, India

New Delhi, often called ‘Dilli,’ has a humid subtropical climate with extremely hot summers.

In the summer of 2023, 60.9% of days fell into the extreme caution category and 27.2% into the danger category.

New Delhi implements a ‘Cool Roofs’ initiative to reduce urban temperatures by encouraging residents to paint their roofs white to reflect sunlight.

#5 New Orleans, United States

‘The Big Easy’ has a humid subtropical climate characterized by hot, humid summers.

During the summer of 2023, 54.3% of days were in the extreme caution category and 22.8% in the danger category.

New Orleans is built below sea level, making it prone to high humidity and heat retention, which significantly elevates the summer heat index.

#6 Bangkok, Thailand

Bangkok experiences a tropical monsoon climate with consistently high temperatures year-round.

In the summer of 2023, 100% of the days were categorized as extreme caution.

Bangkok experiences the urban heat island effect, where temperatures in the city center can be significantly higher than in the surrounding rural areas.

#7 Phnom Penh, Cambodia

Phnom Penh has a tropical climate with high temperatures and humidity.

During the summer of 2023, 97.8% of days were in the extreme caution category.

‘The Pearl of Asia’ encounters the ‘heat dome’ phenomenon. High-pressure systems trap heat in the city, leading to prolonged high temperatures.

#8 Riyadh, Saudi Arabia

Riyadh has a desert climate with extremely high temperatures and very low humidity.

In the summer of 2023, 93.5% of days were categorized as extreme caution.

This capital city uses a vast network of underground water reservoirs to store and provide cool water to the city, helping to mitigate the intense heat during the summer months.

#9 Ho Chi Minh City, Vietnam

Ho Chi Minh City, formerly known as Saigon, has a tropical climate with high temperatures and humidity year-round.

During the summer of 2023, 81.5% of days were classified as extreme caution and 3.3% as danger.

Like Bangkok, Ho Chi Minh City is also affected by the urban heat island effect.

#10 Manila, Philippines

Manila has a tropical savanna climate with high temperatures and humidity year-round.

In the summer of 2023, 85.9% of days were in the extreme caution category.

Manila frequently experiences heat bursts, a phenomenon where temperatures suddenly spike during thunderstorms, making the already hot and humid weather feel even more extreme.