Best time to see the southern lights in São Paulo, Brazil

Updated • 19:57 UTC

São Paulo gets under one clear aurora night a year — 0 in a typical year. Only an extreme storm brings the aurora within reach: nights were counted at Kp 9 or higher, which the planetary index last reached on 11 May 2024. May carries the most of that thin history, at 0.01 in a typical year, which is not a month worth booking.

Typical-year figures: a 1996–2026 planetary Kp record crossed with a 2001–2020 cloud normal. They describe a normal year, not tonight — the live São Paulo forecast shows the actual cloud, moon and darkness right now. Check tonight's forecast for São Paulo →

🌌 Clear nights a year

Challenging — under one clear aurora night a year: 0 in a typical year Compare with Brazil

🌟 Best Month

May

0.01 clear nights in a typical year — a storm night, not a season

🌙 Peak Hours

23:00-01:00

Magnetic midnight

⚡ Required Kp

Kp 9.0+

Served for the live forecast; nights counted at Kp 9, last reached 11 May 2024

🧭 Auroral oval (model)

15.3° below the southern horizon

Model estimate at Kp 9

Month by month in São Paulo

Astronomical darkness, the nights on which planetary Kp reached Kp 9 inside that darkness, the local cloud normal, and what the cloud leaves of the count.

Month	Astronomical darkness	Opportunity nights	Mean cloud	Clear opportunity nights	Moon-free
January	7.78h	0	78.4%	0	53%
February	8.5h	0	68.6%	0	56.3%
March	9.26h	0	65%	0	56.9%
April	9.96h	0	56.9%	0	57.7%
May	10.44h	0.03	57.5%	0.01	57.2%
June	10.62h	0	53.3%	0	57.3%
July	10.47h	0	47.8%	0	57.2%
August	10.13h	0	46.8%	0	57.6%
September	9.51h	0	59.2%	0	58.1%
October	8.76h	0	70.7%	0	55.5%
November	7.95h	0	75.5%	0	53.2%
December	7.52h	0	76.6%	0	53.8%

Opportunity nights are the whole 1996–2026 record. In the current solar cycle alone (since 2023), May has averaged 0.27 rather than 0.03.

May: 10.44h of astronomical darkness a night
May: 0.03 nights reach the Kp threshold inside that darkness
May: 57.5% mean cloud leaves 0.01 of them clear
May: 57.2% of those nights are moon-free

Similar timing: Salta , Rio de Janeiro , Antofagasta

Higher-odds destinations: Fairbanks , Yellowknife , Tromsø

How these numbers were made

Evaluated at: São Paulo, 23.5558° S 46.6396° W — darkness and cloud are properties of that point, not of a region.
Darkness: Sun at or below 18° under the horizon (astronomical twilight), sampled every 10 minutes across every year of the Kp record and averaged per night of each month rather than on one representative day.
Geomagnetic record: GFZ Potsdam planetary Kp index, 3-hourly, 1996–2026 — 89,662 intervals, licensed CC BY 4.0.
Cloud: NASA POWER 20-year monthly climatology (2001–2020), parameter CLOUD_AMT. A monthly mean, not a forecast.
Moon: A night counts as moon-free below 35% lunar illumination while the moon is up.
Auroral oval: NOAA auroral-oval model, equatorward boundary near magnetic latitude 67 − 2 × Kp. A model estimate shown beside the measured record; it never replaces it.
Clear opportunity nights: Nights on which at least one 3-hour Kp interval falls inside local astronomical darkness and reaches the count threshold, scaled by one minus the monthly mean cloud amount.
Kp threshold: Nights were counted at Kp 9 or higher, the same threshold the live forecast serves.
Dataset version: Version 2026-09-07, computed offline from the closed record — the page is regenerated, not forecast.

Kp record: GFZ Potsdam (CC BY 4.0). Cloud normal: NASA POWER. How the live forecast is built: methodology page.

Frequently Asked Questions

When can you see the southern lights in São Paulo?

There is no season for it. São Paulo averages 0 clear aurora nights a year across the 1996–2026 Kp record, so the answer is whenever an extreme storm happens to fall on a dark, clear night. May holds the most of that history, at 0.01 clear nights in a typical year. Watch the live forecast rather than the calendar.

What Kp is needed to see the aurora from São Paulo?

São Paulo needs Kp 9, the top of the scale, for any display low on the southern horizon. The NOAA auroral-oval model puts the edge of the oval about 15.3° below the southern horizon at São Paulo at Kp 9. That is a model estimate, not a ruling on what has been seen. The measured record is the stronger evidence and it disagrees: the planetary index reached Kp 9 on 11 May 2024.

Has the aurora ever been visible from São Paulo?

Yes. In the 1996–2026 planetary Kp record the index reached Kp 9, the threshold these nights were counted at for São Paulo, most recently on 11 May 2024. Whether anyone saw it also depended on the cloud, moonlight and darkness of that night, which the Kp record does not carry.