August 28, 1859

Carrington Event

The Carrington geomagnetic storm disrupts telegraphs and produces low-latitude auroras

Carrington ran to fetch a witness. When he came back about a minute later, the brilliant patches on the Sun had already faded and changed.

1 September 1859: a white spot on the Sun

Richard Carrington, working from his private observatory at Redhill in England, and Richard Hodgson, observing independently, both saw a short-lived white-light brightening over a sunspot group on 1 September 1859. It was the first recorded visual observation of a solar flare.

Carrington left his instrument to fetch another witness; roughly sixty seconds later the patches had already changed.

About 17 hours later

An associated solar disturbance reached Earth on 2 September and produced an extraordinary geomagnetic storm.

Auroras appeared at unusually low latitudes. Well-dated reports include Panama, Cuba, Mexico, Hawaii and locations in South America; the Royal Astronomical Society summarises the reach as far south as the Caribbean.

Magnetographs at Greenwich and Kew were driven off scale, and geomagnetically induced currents disrupted telegraph systems across Europe and North America — equipment sparked or caught fire, and some operators received shocks.

What the record will and will not support

The 28 August date attached to this entry belongs to a distinct precursor storm in the same active sequence, not to the Carrington flare and storm of 1–2 September.

Calling the storm unequivocally the largest ever recorded is not secure. Modern reconstructions put its maximum disturbance at a median −Dst of 964 nT, with a 68% credibility interval of 855–1,087 nT, and place it among the strongest observed; the 1872 and 1921 storms may have been comparable.

Carrington himself cautioned against hastily claiming a causal connection from a single coincidence; the solar–terrestrial interpretation was developed afterward, with Balfour Stewart's analysis of the Kew record published later.

Sources

Researched 23 Aug 2026 8 sources 2 audit passes Date disputed

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date disputed. Sources disagree; the research places it at 1859-09-02.

What the sources leave uncertain

The supplied slug is dated August 28, but the flare now bearing Carrington's name was observed September 1 and the principal geomagnetic storm reached Earth September 2. August 28–29 was a distinct precursor storm in the same active sequence.
Calling the storm unequivocally the largest ever recorded is not secure. Modern reconstructions place it among the strongest observed, while the 1872 and 1921 storms may have been comparable.
A published claim places a Carrington aurora at Montería, Colombia, but its quoted local narrative says the phenomenon occurred in March 1859. It therefore cannot be treated as a securely dated September 2 observation.