Japan suffered its joint warmest summer this year since records began, equalling the level seen in 2023, data from the weather office showed on Monday.
Climate scientists have already predicted that 2024 will be the hottest year on record for the Earth because of a warming planet.
Japan's long-term average temperature between June and August was 1.76 degrees Celsius above the standard value, the joint highest since statistics started being kept in 1898, the Japan Meteorological Agency said.
This July was already the hottest in Japan since records began, with the variation across the archipelago 2.16C higher than average.
In central Tokyo alone, 123 people died of heatstroke in July, when extreme heatwaves saw a record number of ambulances mobilised in the capital, according to local authorities.
Southern Japan was also hit by a major typhoon last week, one of the strongest to hit the archipelago of 125 million people in decades.
Typhoon Shanshan killed at least six people, including three family members in a landslide, and dumped record rain across many areas.
Typhoons in the region have been forming closer to coastlines, intensifying more rapidly and lasting longer over land due to climate change, according to a study released in July.
A rapid attribution analysis by the Imperial College London using peer-reviewed methodology calculated that Typhoon Shanshan's winds were made 26 percent more likely by a warming planet.
A Japanese weather agency official cited the peculiar movement of westerly winds above Japan this year that "made it easier for the archipelago to be shrouded in warm air from the south".
"Also at play is the long-term effect of global warming, which is pushing up average temperature," weather agency official Kaoru Takahashi told AFP.
- Emissions -Scientists say that fossil fuel emissions are worsening the length, frequency and intensity of heatwaves across the world.
From January to July, global temperatures were 0.7C above the 1991-2020 average, according to the European Union's Copernicus Climate Change Service.
Record temperatures have been observed in the Mediterranean Sea, Norway's Arctic Svalbard archipelago and the Ukrainian capital Kyiv in the past few weeks alone.
Australia registered a record-high winter temperature last month, with the mercury hitting 41.6C (106.7F) in part of its rugged and remote northwest coast.
In Europe, Greece has seen 50 percent more summer wildfires this year than in 2023 as well as its earliest heatwave and warmest winter on record.
The rising temperatures are leading to longer wildfire seasons and increasing the area burnt in the flames, according to the United Nations Intergovernmental Panel on Climate Change.