Quadrantids from São Paulo in 2026

Quadrantids from São Paulo: the short answer

The Quadrantids peaks at 18:12 local time on 3 January 2026 over São Paulo. Culmination is 08:32 at 17.0° — 29% of the rate a zenith radiant would give — so the ceiling here is 0.0 an hour, not worth the sleep.

That ranks it 11th of twelve from São Paulo this year, behind the Geminids (7.7/h) and the Perseids (1.9/h).

The radiant track over this city

Bootes carries the radiant. From São Paulo it clears the horizon at 04:34 on a bearing of 34° (NE), reaches 17.0° at 08:32 in the north, and drops back below the horizon at 12:27. Within the observing window it peaks at 3.1°.

When it gets dark here

The dark hours here run 20:24 to 03:58 — 7 h 34 min of astronomical night, bracketed by sunset at 18:57 and sunrise at 05:25. Civil twilight ends at 19:22; anything earlier than that is wasted effort.

Local solar midnight, the true middle of the night, falls at 00:11 here rather than at 00:00: America/Sao_Paulo runs 7 minutes ahead of mean solar time at 46.64°W. That offset is why the best hour on this page is not the hour you would guess from the clock.

What the Moon does here

Moonlight is the limiting factor on this night from São Paulo. The Moon is 99% lit and only 0 of 10 sampled hours are moon-free. Moonrise 19:34. Moonset 06:25. At the best hour it stands 4.2° above the horizon, 85° from the radiant, pulling the limiting magnitude down to 2.38.

Why 0 an hour and not 110

The published ZHR of 110 assumes the radiant overhead and a sky at limiting magnitude 6.5. Here the radiant reaches 3.1° inside the dark window and the limiting magnitude at the best hour is 2.38, which with r = 2.1 gives 0.0 an hour. Entry speed is 40.4 km/s.

Hour by hour the modelled rate runs from 0.0 at 20:00 (radiant -63.2°) to 0.0 at 05:00 (radiant 3.1°), peaking at 0.0. That spread across 10 hours is why a "what time" answer beats a "how many" answer.

The stream comes from Minor planet 2003 EH1 and Comet C/1490 Y1 and is listed as active 28 December to 12 January, so 3 January 2026 is the best night from São Paulo rather than the only one.

Watching from around São Paulo

São Paulo is the 12th largest of the 300 cities covered here, with a population of 12.40 million at 769 m above sea level. The nearest other cities on the site are Curitiba (339 km SW), Rio de Janeiro (360 km E), Belo Horizonte (490 km NE) — close enough that the radiant altitudes barely change, far enough that sunset and moonrise do.

What this page does not know

Rates on this page are computed against this city's own measured sky brightness, derived from satellite night-lights data. That is a calculated brightness for the point directly overhead, not a survey of your street: a park on the edge of town and a lit car park in the centre share the same figure here and will not look the same. It is also zenith-only, while the Bortle scale describes the whole sky from horizon to horizon.

Cloud cover is a forecast, not a constant, so it is resolved when you load the tonight card and is deliberately absent from this prerendered page — the hourly table shows "unavailable" rather than assuming clear skies. Meteor outbursts, local terrain and building horizons are not modelled.

A single observer with an unobstructed horizon typically records 30–50% below the ideal-sky figure. Give your eyes twenty minutes to adapt, keep bright screens away, look about halfway up the sky rather than straight at the radiant, and count for a full hour before judging a shower.