A day with at least strong heat stress has a maximum feels-like temperature of 32°C or more, and a day with at least strong cold stress a minimum feels-like tempe rature of -13°C or below. Data: ERA5-HEAT Universal Thermal Climate Index (UTCI) · Reference period: 1991-2020 · Credit: C3S/ECMWF and at least strong cold stress (right), relative to the average for the 1991-2020 feels-like temperature, based on the Universal Thermal Climate Index (UTCl), of 32°C or more, and a day with at least strong cold stress has a minimum feels-like temperature of -13°C or below. Data Source: ERA5-HEAT. Credit: C3S/ECMWF. of -13°C or below) in 2025. This is typically up to 10 days more than average, and includes an area covering July for example, alongside southern USA and southwestern Australia. In northwestern USA, some areas saw up to 25 more days with at least strong cold stress, and parts of northern USA and Canada also saw more days See the chart online You can explore our online graphics gallery for an interactive version and to access the data behind it.