Since the 1980s, satellites and reanalysis models have let scientists track how surface temperature is changing, not just on average, but region by region. This animation shows the linear trend in 2-metre air temperature (ERA5 reanalysis, 1979-2025) across the globe, in K/decade. The surface is both colored and deformed by the trend: it bulges outward where warming is fastest, and dips inward in the rare pockets that have cooled. To be clear, this is a visualization device, not a physical measurement.

A follow-up to the annual version of this animation (ERA5, 1940-2025): same reanalysis, same 1991-2020 baseline, but this time month by month instead of year by year, and starting in 1982 instead of 1940 to keep the frame count manageable. Going monthly changes what the animation shows. The annual version told the story of the long-term trend, decades slowly shifting from blue to red.

We know, we live in a changing world. How temperature is evolving is just a measure for that change and how we might be feeling it.

Here we have 61 years of changing global temperatures (Data exported from ERA5).

Data: ERA5

Ocean temperature doesn't just respond to a warming atmosphere, it also stores the overwhelming majority of the extra heat trapped by greenhouse gases, over 90% of it. This animation shows the linear trend in sea surface temperature (ERA5 reanalysis, 1940-2025, 86 years of data) across the globe, in K/decade. Land is shown in flat gray; the trend is oceanic only.

From 1940 to 2025, sea surface temperature compared to the 1991-2020 average. Blue, cooler. Red, warmer. One frame per year.

The map is a Spilhaus projection: it cuts the planet through the continents instead of through the ocean, so you see in one piece what we always treat as four separate oceans. It's one.

The sea has absorbed close to 90% of the excess heat from global warming. This animation is that bill, year by year.

Data: ERA5, Copernicus Climate Change Service (C3S)