How Many Heat Records Did Miami Melt in July?

Miami just made it through its hottest July on record.

The past few weeks brought a blistering heat, coupled with unrelenting humidity, that frazzled even the most sun-baked, alligator-skinned Floridians among us. Miami set more daily heat records last month than any other July — the highest daily temperature for seven dates and highest heat index for 19 dates, according to University of Miami data stretching back to 1948.

The steamy weather lingered in place for weeks in part because of high ocean temperatures, which robbed residents of the sea-breeze cooling effect that usually alleviates the South Florida heat, meteorologist Sammy Hadi told New Times at the height of the heat wave.

On July 16, the National Weather Service issued its first-ever "excessive heat warning for South Florida," triggered by a forecast that the heat index would reach 110 degrees for more than two hours. (The advisory was issued under a new standard that lowered the threshold for a warning from a heat index of 113 degrees to 110 degrees.)

Tens of thousands of Miami metro residents who work in agriculture, construction, and outdoor service industries bore the brunt of the heat wave.

There were at least two documented heat-related deaths among South Florida agricultural workers this year, which prompted protests and outcry from worker advocacy groups. The Miami-Dade County Commission passed a first reading of a proposal that, if it receives final approval, would give construction and agriculture workers the right to a ten-minute shaded break every two hours on hot days, among other safeguards.

The South Florida heat came amid the globe's hottest month on record, according to European climate data. The European Centre for Medium-Range Weather Forecasts (ECMWF) said last week that in addition to unprecedented sustained surface temperatures, one date last month, July 6, marked the hottest day ever recorded in terms of average global temperature.

On July 28, Miami ended its 46-day streak of heat indices above 100 degrees.

"This blew past the previous record of 32 consecutive days… Incredible," meteorologist Brian McNoldy tweeted, noting the previous record in August and September 2020.

But Magic City managed to slip in one final scorcher, logging a 107-degree heat index on July 31, the highest ever recorded for that date.

Humans weren’t the only ones feeling the burn in July.

Florida’s coral reefs and marine life face unprecedented mortality and stress due to a climb in ocean temperatures.

According to NOAA’s Coral Reef Watch, most reefs in the Keys are currently classified under heat stress Level 2, the highest possible stress level, which entails "severe coral bleaching and significant coral death (mortality is likely)," the site states. (This isn’t a new phenomenon. Last year, a NOAA study found that 70 percent of studied sites in the Florida Reef were in an erosional state due to bleaching, habitat loss, and disease.)

Sea surface temperatures reached 101 degrees last week between the peninsula and the Keys, which was hotter than the air outside.

"Day after day, the record-smashing anomalies in the atmosphere and ocean around the world this year are just jaw-dropping," McNoldy tweeted. "Unlike anything we’ve seen."

While the heat streak has retreated in the first week of August, South Florida residents are not getting the perfect beach day just yet: forecasts continue to call for isolated showers throughout the week. The rain and accompanying cloud cover might cool things intermittently, though several days stretching from early to mid-August are forecast to have daily high temperatures in the low 90s.