Southern delta-Aquariids from Harbin in 2026

Southern delta-Aquariids from Harbin: the short answer

The Southern delta-Aquariids peaks at 21:23 local time on 31 July 2026 over Harbin, Heilongjiang. Culmination is 01:41 at 28.3° — 47% of the rate a zenith radiant would give — so the ceiling here is 3.6 an hour, not worth the sleep.

That ranks it 12th of twelve from Harbin this year, behind the Geminids (145.4/h) and the Perseids (84.5/h).

The radiant track over this city

The radiant rises at 20:50 bearing ESE, culminates 28.3° up at 01:41 towards south (180°), and sets at 06:33. It lies inside Aquarius. The rate scales with the sine of that altitude, so 28.3° buys you 47% of a zenith radiant.

When it gets dark here

The dark hours here run 21:13 to 02:06 — 4 h 53 min of astronomical night, bracketed by sunset at 19:03 and sunrise at 04:16. Civil twilight ends at 19:38; anything earlier than that is wasted effort.

Local solar midnight, the true middle of the night, falls at 23:40 here rather than at 00:00: Asia/Shanghai runs 27 minutes behind mean solar time at 126.65°E. 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 Harbin. The Moon is 96% lit and only 0 of 8 sampled hours are moon-free. Moonrise 19:53. Moonset 06:45. At the best hour it stands 32.4° above the horizon, 8° from the radiant, pulling the limiting magnitude down to 5.47.

Why 4 an hour and not 25

The published ZHR of 25 assumes the radiant overhead and a sky at limiting magnitude 6.5. Here the radiant reaches 28.2° inside the dark window and the limiting magnitude at the best hour is 5.47, which with r = 3.2 gives 3.6 an hour. Entry speed is 40.6 km/s.

Hour by hour the modelled rate runs from 0.0 at 20:00 (radiant -8.3°) to 0.1 at 03:00 (radiant 25.8°), peaking at 3.6. That spread across 8 hours is why a "what time" answer beats a "how many" answer.

The stream comes from Comet 96P/Machholz and is listed as active 12 July to 23 August, so 31 July 2026 is the best night from Harbin rather than the only one.

Watching from around Harbin

Harbin, Heilongjiang is the 54th largest of the 300 cities covered here, with a population of 5.24 million at 140 m above sea level. The nearest other cities on the site are Daqing (157 km NW), Jilin (212 km S), Changchun (233 km SSW) — close enough that the radiant altitudes barely change, far enough that sunset and moonrise do.

What this page does not know

Light-pollution data for this location is not connected yet. Rates on this page are computed against the reference rural sky the zenithal hourly rate is defined for (naked-eye limiting magnitude 6.5); they are not a claim about how bright the sky is where you are standing. Once the light-pollution layer is connected these figures will be recomputed for the local sky and will generally fall.

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.