ERA5 reanalysis · 1961-1990 against 2015-2024

Las Vegas gets 30.7 more hot days a year than it used to

A hot day in Las Vegas means 105.4F or hotter, which was the top tenth of summer days here between 1961 and 1990. Las Vegas averaged 9.5 of them a year over that period and averages 40.2 now, a difference of 30.7. Summer highs run 5.1F warmer.

1961-19902015-2024
Hot days a year, 105.4F or hotter9.540.2
Days a year at 90F or hotter110.7136.5
Average summer high, F98103.1

Questions

What counts as a hot day in Las Vegas?

105.4F. That was the 90th percentile of a Las Vegas summer day between 1961 and 1990, so it is a local definition rather than a national one. A fixed national threshold would report almost no change in the coolest cities and almost none in the hottest, which is a property of the threshold and not of the weather.

Is this the temperature record at the airport?

No, and it should not be read as one. These are reanalysis values: a model reconstruction on a grid roughly 31 km across, which is consistent over six decades and between cities in a way station records are not. That consistency is what makes the comparison possible, and it is also why a single day here will not match a thermometer reading.

Last updated 2026-08-15.

Sources. ERA5 reanalysis via the Open-Meteo archive, daily maximum 2 m air temperature, for 1961-1990 and 2015-2024.