May 2025 was one for the record books. Data shows Tampa’s average temperature for the month reached 82.6 degrees F — making it the second warmest May on record, just behind 2024’s scorching 83 degrees. That average is 3.15 degrees above normal, with the city experiencing both extreme highs and persistently warm lows. This year’s heat wasn’t just a fluke — it’s part of a long-term trend. Since 1970, Tampa’s May temperatures have increased by 4.3 degrees, according to data from Climate Central. The graphic below shows a clear upward trend over the last five decades. Meteorologists point to several reasons for the heat. A warmer-than-normal Gulf of Mexico, persistent high pressure and a lack of rain early in the month helped drive up temperatures. By late May, sea surface temperatures in the eastern Gulf were 5 to 7 degrees above normal. That warmth pushed inland on a steady onshore flow, keeping overnight temperatures elevated across the Tampa Bay region. Tampa didn’t just sweat during the afternoons — the city also experienced historically warm mornings, with seven new daily minimum temperature records set or tied. The lowest morning temp of 81 degrees on May 29 marked the warmest low ever recorded in Tampa during the month of May. These unusually high morning temperatures are part of another emerging pattern: overnight lows are warming faster than daytime highs. Since 1970, mornings in Tampa have steadily warmed, especially during spring and summer. This May, 20 days in Tampa reached level 2 or higher on the Climate Shift Index (CSI) — a scale that shows how much human-caused climate change increased the likelihood of a given day’s temperature. A CSI level of 2 indicates that climate change had a strong effect on the day’s heat. The data make one thing clear: Tampa is heating up, and not just during the hottest part of the day. As climate change continues to influence our local weather, residents can expect more warm mornings, hotter days and shifting weather patterns in the months and years ahead.