The planet is getting hotter: what it means for what we wear

What the records show

The Copernicus Climate Change Service reported in January 2026 that 2025 was the third warmest year on record, at 1.47 °C above the 1850 to 1900 average, after 1.60 °C in 2024. The three years from 2023 to 2025 averaged more than 1.5 °C above that level, the first time any three year period has done so.

The World Meteorological Organization drew the same picture in its State of the Global Climate 2025, published in March 2026. It put 2025 at about 1.43 °C above the 1850 to 1900 average, and found that the eleven years from 2015 to 2025 were the eleven warmest on record. Ocean heat content reached a new record high in 2025.

NASA’s record goes back further, to 1880. In its GISTEMP analysis, the three warmest years are 2024, 2025 and 2023, and every year since 2015 has been warmer than every year before it. The last ten full years averaged about 1.2 °C more than the 1880s.

What a hotter year feels like

Averages hide the days that matter. Copernicus found that in 2025, half of the world’s land area had more days than average with a feels like temperature of 32 °C or above.

For many of us that means more hours outside in heat and strong sun at the same time: the walk to work, the wait at a crossing, the evening training session, the long lunch at a table outdoors. Clothing has to deal with both at once.

Covering up without overheating

Heat and sun pull in opposite directions. Heat makes people want less fabric, while the sun is easier to manage under more of it. Clothing made for a hotter world has to cover the arms, the neck and the shoulders while staying light enough to forget about.

Cut is part of the answer. In a 1980 study published in Nature, a person standing in desert sun in a loose black robe took on about the same heat as in a loose white one, because the extra heat in the black cloth was lost to the moving air before it reached the skin. Loose cuts, light fabric and quick drying knits all help clothing cover more without trapping heat.

Clothing does not wash off

Some of what people put on for the sun ends up in the sea. To protect their reefs, Hawaii banned the sale of sunscreens containing oxybenzone or octinoxate from 1 January 2021, and Palau banned the sale of sunscreens it defines as toxic to reefs from 1 January 2020. A shirt does not wash off into the water.

What it means for how we make clothing

We think clothing should be made for the sun we actually live in, not for a cooler world. That is why every Rezzella piece is made to block the sun. The Sun Hoodie is far lighter than a cotton hoodie, with a deep hood and thumbholes, and the Riviera Shirt is a long sleeve shirt in a light woven with the look of linen.

A hotter world also asks something of the people who make clothing. We make every piece to order, so nothing is made on a guess, and we will publish the fabric and the laboratory report for every piece. Why we make every piece to order explains the first, and For the planet sets out the rest.

Facts, not slogans

Climate is easy to talk about loosely. We would rather quote the agencies that measure it, link to their reports and date what we found, so you can check every figure here yourself, against the date we checked it.