Is it too hot this summer? Visualize temperature comparison data for 2024 and 2025
![Is it too hot this summer?] ](/images/2025-07-28-summer-temperature-compare/main.jpg)
In the summer of 2025, every time you go outside, do you feel like it's hotter than last year..."?
This time, we compared the summers of 2024 and 2025 based on actual temperature data to visualize whether the experience was really correct.
Comparison of Temperature Data
In Osaka (Japan Meteorological Agency's observatory), the maximum temperature for July 1 to 27 in 2024 and 2025 was obtained by day and graphed as follows.
*Data source: From past weather data of the Japan Meteorological Agency
In 2025, there is clearly an increase in "extremely hot days" of 35°C or more, especially since the middle of the month, with daily records of 35-37°C.
Comparing the Percentage of Extremely Hot Days
-
2024
- Extremely hot days (35°C or higher): 6 days
- Percentage of total: about 22%
-
2025
- Extremely hot days (35°C or higher): 13 days
- Percentage of total: about 48%
Not a simple difference in average temperature,
"How many days of dangerous heat are increasing" is an important point.
In July 2025, there will be almost one extremely hot day every two days.
It is clear from the numbers that we feel that it is an abnormal summer.
The "quality" of heat is changing
This year, we're also seeing the following changes:
- Nighttime temperatures do not drop (increased tropical nights)
- High humidity and high perceived temperature
- Less wind, more likely to trap heat in urban areas
According to the "Heat Index (WBGT)" shown by the Japan Meteorological Agency, the number of days exceeding the heat stroke warning line will increase in 2025.
Knowing Data Changes Your Measures
Now that we know that "it's not my fault to feel hot," the measures we can take will also be clear.
- Review of going out time (mainly early morning and evening)
- Don't hesitate to set the indoor air conditioner
- For families with children and the elderly, it is also effective to grasp the WBGT (heat index: an indicator of heat stroke risk that combines humidity, temperature, sunlight, etc.).
Conclusion
If you look at the numbers, you can see that the summer of 2025 will indeed continue to be "abnormally hot".
If you feel uneasy about your physical condition, don't overdo it and rest. And try to keep in mind lifestyle habits with data as your ally.