About Your Personal Climate Stripes
Ed Hawkins’ warming stripes strip a temperature record down to the one thing everybody can read: colour. No axes, no numbers, no labels — just one bar per year, blue below the local average, red above. This makes them for your town, across your lifetime.
The series comes from ERA5, the reanalysis that rebuilds the atmosphere from every observation taken since 1940. Daily readings at your coordinates are reduced to annual means, expressed as anomalies against a thirty-year baseline, and scaled the way Hawkins scales the originals — saturating at roughly two and a half standard deviations.
Two warming numbers are given, deliberately. The fitted trend uses every year in the series and is what a climatologist would quote. The first year against the last is the punchier number and rests on exactly two data points, which makes it hostage to whether your birth year happened to be a cold one. Showing both, and saying which is which, is the difference between a chart and a claim. Local records are also far noisier than the global average, so expect a messier pattern than the famous version — that is real, not a bug.
Draw a second town’s stripes over the same years — the place you were born against the place you live now.
Download your stripes as a scalable SVG poster — print it at any size without it going fuzzy.
How to Use Your Personal Climate Stripes
Type the year you were born, search for a town, and press the button. The chart draws one bar for every complete year from your birth to the last full calendar year. Colour is relative to that town’s own average, not a global one, so a blue bar in Phoenix and a blue bar in Helsinki mean the same thing: cooler than normal there. Read the pattern first, then the numbers underneath it.
Where Warming Stripes Came From
Ed Hawkins, a climate scientist at the University of Reading, published the first warming stripes in 2018 after a simple observation: conventional climate charts require you to read axes, understand baselines and interpret trend lines before the message arrives, and most people never get that far. So he removed all of it. What is left is a barcode of colour that anybody understands in under a second, and it went on to appear on everything from football shirts to the side of buildings.
The scaling is not arbitrary. Each year’s colour comes from its anomaly — how far it sat above or below a long-run reference average — divided by the standard deviation of that reference period, and the palette saturates at roughly two and a half standard deviations. Using variability rather than a fixed temperature span is what makes stripes for different places comparable at a glance: a hot year in a stable tropical climate and a hot year in a wildly variable continental one are both shown relative to what is normal for that spot.
Two Numbers, and Why They Disagree
The obvious way to answer “how much warmer is it than when I was born?” is to subtract your birth year from last year. It is also the wrong way. That figure rests on exactly two observations, and single years bounce around by a degree or more for reasons that have nothing to do with a trend — El Niño and La Niña, a volcanic eruption, a stuck jet stream. If your birth year happened to be a cold one, the number flatters; if it was warm, it flatters the other way.
The fitted trend shown here uses every year through a least-squares regression, so no single year can dominate, and it is what a climatologist would quote. Both figures are displayed because the gap between them is itself informative: when they differ a lot, your first or last year was unusual, and knowing that is more interesting than a single confident number would have been.
Why Your Local Stripes Look Noisier Than the Famous Ones
The global warming stripes are almost monotonic: blue on the left, red on the right, very little argument in between. Yours will not be. That is not an error, it is a consequence of averaging. Averaging the whole planet cancels out regional weather; a single town keeps all of it. Local year-to-year variability typically runs several times larger than the warming signal accumulated over a few decades, so the trend has to emerge from real noise rather than sitting on top of a flat line.
Two consequences worth understanding. First, a short record is not enough — over ten or fifteen years the noise dominates completely and the fitted trend means very little. Second, a cold year proves nothing, in either direction; every warming record contains plenty of them. The signal lives in the balance across decades, which is precisely what the stripes make visible.
Warming Is Not Spread Evenly Across the Year
The seasonal panel is where most people get their genuine surprise. Across much of the northern mid-latitudes, winter has warmed several times faster than summer. Snow and ice are the mechanism: as they retreat, the ground stops reflecting sunlight and starts absorbing it, which amplifies warming exactly where and when there used to be snow. It is why the Arctic is warming several times faster than the global average, and why your winters may have moved far more than your summers.
This has a practical edge. Winters shortening changes which plants survive, which pests survive, when rivers freeze and when they flood. A number nobody feels — an annual average up by a degree — can be a winter that is now four degrees milder, which everybody feels.
Want a single day rather than a lifetime? The Day You Were Born gives you the actual weather, moon phase and prices for the day you arrived. Browse every Fun & Novelty tool for more.
Frequently Asked Questions
What are warming stripes?
A graphic devised by climate scientist Ed Hawkins at the University of Reading in 2018. Each vertical bar is one year, coloured by how far that year sat above or below a long-run average — blue for cooler, red for warmer. There are no axes, no numbers and no labels, which is the whole point: it removes every barrier to reading a temperature record and leaves only the pattern.
Why is the trend number smaller than the difference between my first and last year?
Because single years are noisy. A first-versus-last comparison rests on exactly two years, and if either happened to be unusually warm or cool the answer moves by a degree or more for reasons that have nothing to do with a trend. The fitted trend uses every year in the series, so no individual year can dominate. When the two figures disagree sharply, it is telling you that your birth year was itself unusual — which is worth knowing.
Why do my local stripes look messier than the global ones?
Because averaging suppresses noise, and the global chart averages the entire planet. A single location swings around far more from year to year thanks to weather patterns, ocean cycles and local effects, so the warming signal has to fight through much larger variation. The trend is usually still there; it is just less tidy. That is a genuine feature of climate data at small scales, not a flaw in the chart.
Which season is warming fastest where I live?
The tool works it out from your own data, and the answer surprises people. In much of the mid-latitude northern hemisphere it is winter, by a wide margin, while summers have moved comparatively little. Warming is not evenly spread across the year, and the seasonal breakdown shows how it lands where you are.
Where does the temperature data come from?
From ERA5, the European Centre for Medium-Range Weather Forecasts reanalysis, which reconstructs the atmosphere from 1940 to the present using every observation recorded at the time. Because the same model is applied to every year, readings from 1950 and 2020 are directly comparable — something raw station records cannot promise, since instruments and station sites changed underneath them.
