A Three-Year Stretch Just Averaged Above 1.5°C: The New Sun-Exposure Baseline
The 1.5°C line everyone talks about has effectively been crossed on a multi-year basis, normalizing the heat-and-sun extremes that make year-round UV protection sensible.
Global temperatures for 2023 to 2025 averaged more than 1.5°C above pre-industrial levels, the first time any three-year period has crossed that threshold, according to Copernicus data, with 2025 reported as the third hottest year on record.
Climate scientists at the Copernicus Climate Change Service note that crossing 1.5°C on a multi-year basis marks a new baseline, reinforcing public-health guidance to treat UV protection as a year-round habit.
Questions we get a lot
Did global temperatures really cross 1.5°C?
Yes, on a multi-year basis. Global temperatures for 2023 to 2025 averaged more than 1.5°C above pre-industrial levels, the first time any three-year period has done so, according to Copernicus data. This is a longer-term signal than a single hot year, which is why scientists treat it as a meaningful threshold.
Was 2025 the hottest year on record?
According to the Copernicus Climate Change Service, 2025 was the third hottest year on record. While not the single hottest, it contributed to the 2023-2025 average exceeding 1.5°C above pre-industrial levels. The sustained warmth reinforces the trend toward hotter, sunnier conditions.
What does crossing 1.5°C mean for sun protection?
Warmer, sunnier conditions make year-round UV exposure more of a practical concern, not just a summer one. The better cue for sunscreen is the daily UV index rather than the season or temperature. Treating UV protection as a daily habit aligns with the new baseline reflected in the 2023-2025 climate data.
r/climate: 'I keep seeing we crossed 1.5°C. Does that change anything practical, like how I should think about sun exposure?'