ERA5 reanalysis · 1961-1990 against 2015-2024

Miami gets 45.4 more hot days a year than it used to

A hot day in Miami means 87.3F or hotter, which was the top tenth of summer days here between 1961 and 1990. Miami averaged 11.4 of them a year over that period and averages 56.8 now, a difference of 45.4. Summer highs run 1.9F warmer.

1961-19902015-2024
Hot days a year, 87.3F or hotter11.456.8
Days a year at 90F or hotter112.1
Average summer high, F84.886.7

Questions

What counts as a hot day in Miami?

87.3F. That was the 90th percentile of a Miami 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.