Hot and Bothered

Hot and Bothered  

Japan to Sizzle This Summer–El Niño Not All to Blame   

Planning a trip to Japan this July or August? A little precaution and preparation may be advised. 

As if Japan’s summer of 2023 was not hot enough, nudging the mercury nearly two degrees above average, the Japan Meteorological Agency (JMA) hints we have another thing coming this year.  

If this year’s Golden Week roast in May was any indication of JMA’s foreshadowing, Japan could expect a pattern-consistent heatwave to remember for decades. For example, in Kyoto, one of the most sought travel destinations in Japan, visitors and residents alike felt the temperatures topping 25 degrees during the Golden Week holidays this May.  

Kyoto City is in a basin surrounded by three low mountains that block cooling winds from the north and the Sea of Japan to the east. As karma might dictate, the lackluster 1997 Kyoto Protocol, named after the city, arguably had failed to achieve carbon dioxide emission reduction goals. 

As the planet empirically heats yearly, accusing fingers might point toward El Niño, a natural phenomenon, for alleged sultry crimes against humanity. The warming trend of the tropical Pacific Ocean surface temperatures is responsible for El Niño’s climate pattern, disrupting regional weather patterns, marine conditions, and ecosystems.  

The red streak in the photo shows above-average monthly surface temperatures across the tropical zone of the Pacific Ocean in January 2016, relative to 1981-2010 average. Image by climate.gov/NNVL. Data: Geo-Polar SST.  

As the El Niño effect wanes, a shift in global atmospheric circulation patterns may increase the expected heat over the next three months. According to the JMA, the converging conditions for high temperatures are a recipe for a summer hotter than 2023. The probability of above-normal summer occurrences is 50% or higher in the entire Japanese archipelago. 

However, El Nino, which cannot bear all the guilt for our sweaty woes, paints only a part of the picture about 2023’s record-burning temperatures.  

Although prediction systems by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) indicate El Nino’s gradual disappearance by late summer’s end, its problematic energy remains. With unmitigated greenhouse gas emissions, that energy appears only to build up akin to a pressure cooker and prolong the summer heat.  

Warmer news from the JMA also forecasts significantly heavier rainfall between the flood-prone months of June and October. 

“With a hotter spring in the Indian Ocean stimulating the monsoons, we need to be vigilant about an extra powerful rainy season during which the air heat effect will peak,” explains JAMSTEC’s senior climate researcher Takeshi Doi in a Japan Times article on 18 Feb 2024. 

Evidence for the warming trend ahead of the summer of 2024 comes from JMA’s recent report that the average winter temperature between December 2023 and February 2024 was 1.27 degrees Celsius above normal, only 0.16 C short of the warmest rise recorded in 2020.  

Unfortunately, these figures may not seem dramatic enough to make a splash on the front pages, which does not help people connect the dots. Therefore, residents tend to forget to prepare themselves for preventable risks that accompany hot summers. 

On 24 April 2024, the Ministry of the Environment and the JMA initiated the nation’s heat-related illness prevention alert system. Such reports remind Japan’s residents of the health risks due to heat stroke. Each prefecture issues the Special Heat Stroke Alert when the Wet Bulb Globe Temperature (WBGT)—a heat stroke risk indicator based on factors such as temperature and humidity—reaches 35 C at all observation points. That precarious threshold has yet to be reached, but some prefectures annually sound the conventional Heat Stroke Alert when temperatures hit 33 C.  

Throughout Japan, familiar green or yellow signs mark evacuation sites for tsunamis, earthquakes, floods, and large-scale fires. Soon, heat stroke will join that list following the Special Heat Stroke Alert mandate. As reported by NHK World Japan, residents can expect their local governments, with the cooperation of schools and businesses, to plan cooling shelters or emergency air-conditioned facilities. These relief centres are a temporary solution to a symptom of a larger global problem that continues to grow. 

As the heat intensifies, Japan and its visitors may have to brace for impact this summer with the trifecta of natural seasonal changes, El Niño, and human-caused agitators of climate change.