2024 Was the First Year Above 1.5°C — The Heat That Set Up 2025's Sun Season
The hottest year ever recorded rolled straight into 2025 — a useful lens for why high-UV days are creeping into more of the calendar.
In January 2025 the World Meteorological Organization confirmed 2024 as the warmest year on record at about 1.55°C above the 1850-1900 average — likely the first calendar year to exceed 1.5°C.
WMO scientists caution that a single year above 1.5°C does not mean the long-term Paris Agreement threshold has been breached, since that goal is assessed over multiple decades — but they describe 2024 as a clear warning sign for the warming-driven exposure trend.
Questions we get a lot
Was 2024 really the hottest year on record?
Yes. In January 2025 the World Meteorological Organization confirmed 2024 as the warmest year on record, at about 1.55°C above the 1850-1900 pre-industrial average. It was likely the first calendar year to exceed 1.5°C. The figure draws on multiple global temperature datasets.
Does one year above 1.5°C mean the Paris goal is breached?
No. The WMO is careful to note that a single calendar year above 1.5°C does not equate to breaching the Paris Agreement's long-term goal, which is measured over decades. 2024 is best read as a warning sign rather than a formal threshold breach. The long-term trend, not one year, defines the target.
What does this warming trend mean for sun protection?
Record warmth tends to extend warm seasons and increase clear-sky days, which can raise cumulative UV exposure over the year. The WMO's confirmation of a record-hot 2024 reinforces treating sun protection as a daily, year-round habit. Heat and UV differ, but both rise within the same broad trend.
r/climatechange: 'If 2024 already passed 1.5°C, does that mean the Paris target is blown — and should I be thinking about sun exposure differently?'