Number of days per year with a daily minimum temperature exceeding 25°C (77°F) at the ”potential” climate warming scenario of +2.0°C. On the current path of emissions, in the 2040s the average surface temperature will likely pass 2.0°C above the pre-industrial 1850-1900 average (a standard baseline time period in climate science). The lowest temperature during the day happens at night when temperatures dip after sunset. The human experience of a “hot” night is relative to location, so a threshold of 20°C is often used for higher latitudes (Europe and the US) and a threshold of 25°C is often used for tropical and equatorial regions. The displayed values are from a range of simulated years from multiple models. Actual outcomes may prove to be higher or lower than the displayed values.