THE LATITUDE LOOM

A global average
hides the planet.

One number a year says the Earth is warming. It cannot say that the Arctic is doing it three times over while a belt of the Southern Ocean barely moves. So keep the latitude: every year a column, every 2° band of latitude a thread.

Reading the archive…

All longitudes · land and ocean

01 · THE TAPESTRY

Every year, from pole to pole.

Lens

Colour

YEAR LATITUDE BAND Follow the pointer

FROM THROUGH

°C

——Area mean, all longitudes

TEMPERATURE—2 m, land and ocean

DEPARTURE—From this band's 1991–2020 mean

REFERENCE—This band, this lens, 1991–2020

02 · TWO CUTS THROUGH ONE CELL

A thread through time, and a year across the Earth.

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Each point is a year; choose one to move the whole page to it. The dashed line is the fixed 1991–2020 reference.

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03 · THE SAME SLICE, WHOLE

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Each of these is its own area mean of the whole grid, not an average of the band values above — which would weight a band at the pole like a band at the equator.

GLOBAL—

NORTHERN HEMISPHERE—

SOUTHERN HEMISPHERE—

TROPICS · 23.5°S–23.5°N—

04 · HOW TO READ IT

A departure needs a reference you can name.

01 / THE FIELD

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02 / THE WEIGHT

Each band spans every longitude. The weights are exact spherical cell areas: a cell on a band's edge counts for the fraction of it that falls inside, and a cell at a pole is half as tall. The 90 bands sum to the sphere, so they reproduce a global mean rather than approximate one.

03 / THE GAPS

A band with one missing cell has no value, because a mean of what is left describes a different piece of the planet. A reference needs all thirty years of 1991–2020 present, or the build stops. Nothing is infilled with zero.

04 / THE COLOUR

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These are slices of one calendar month and one calendar day — not annual means, and not trend estimates. Reanalysis is a model's best gridded estimate of the past, constrained by observations; it is not a station record.

See this year's maps in the Explorer

05 · THE NUMBERS

Every value on this page, and where it came from.

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Download this band as CSV Download the whole snapshot Poster, high-resolution PNG

The selected band, year by year

The selected latitude band's temperature, reference mean and departure, by year
YEAR	°C	1991–2020 °C	DEPARTURE	SOURCE