Students across Sweden took part in a year-long citizen science project called "Kallt och svettigt" (Cold and sweaty), aimed at exploring how people experience temperature and whether there are differences in how weather is perceived in various regions. Between fall 2025 and summer 2026, over 6,000 students aged 10 to 15 interviewed adults about their feelings toward different temperatures and recorded the actual temperature during those interviews. The collected data were sent to Gabriele Messori, a professor of meteorology and the project’s lead researcher, along with his colleagues at Uppsala University’s Department of Earth Sciences. Preliminary findings suggest that there are noticeable differences in how people in various parts of Sweden perceive the weather. Those in southern Sweden tend to find the temperature more pleasant than people in the north. One possible reason is that many individuals prefer mild warmth over colder conditions. However, an exception exists in the southern province of Scania, where summer temperatures can become too high, reducing comfort even though the temperatures are warm. While moderate warmth generally improves perceived comfort, temperatures above about 25 degrees Celsius (77 degrees Fahrenheit) can start to feel uncomfortable. Local environments also play a significant role in temperature differences. For instance, cities with many tall buildings tend to be warmer than neighborhoods with more trees and smaller buildings. This means that people living close to each other can have different perceptions of the same temperature, and local weather forecasts might not always be accurate for specific areas. A city that is much warmer than the surrounding suburbs is known as an urban heat island. This effect is usually more pronounced at night and during winter than during the day or in summer. The findings from the project could help shape the development of Sweden’s cities, such as by planting more trees in areas where temperatures are often perceived as uncomfortably hot. Temperature has a strong influence on how people feel, especially during extreme heat or cold. The project has provided valuable insights into how different environments affect temperature and how people perceive the climate—important considerations for the present and future. Researchers have now received the final results and hope to compile and analyze the data soon, with plans to publish their findings in a scientific journal.