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Itsukaichi

35.725° N 139.218° E · 184 M

57 /100
PEAK

Worth setting up — 1 hour of workable sky from 02:00.

BEST WINDOW 02:00–03:00 · ASTRO DARK 02:00–04:00 · MOON 0%

Transparency

0.26

Seeing

1.00

Cloud

17%

Moon

Good tonight

Hour by hour, local to Itsukaichi. Colour encodes the score and nothing else; every other measurement is luminance.

Sky state

Lighter = daylight and twilight · unshaded = astronomical dark

Score

BEST WINDOW

Low cloud

11%

73%

31%

27%

Mid cloud

43%

High cloud

52%

70%

41%

Transparency

0.23

0.26

0.24

0.10

Seeing

1.00

Moon clear

down

Inspect

Cloud tracks show clear sky — a longer bar is better. The figure inside each track is the raw measurement.

Why this hour scored what it did

02 Good · 57/100

Starting from

100

Cloud

−18

Transparency

−26

Seeing

−0

Moonlight

−0

Darkness

−0

Score

CLOUD 17% LOW 11% MID 8% HIGH 1% SUN -30.5° MOON -30.3° / 0% WIND 1 TEMP 21°

Excellent 75+ Good 55+ Fair 35+ Poor 15+ Not worth it Seeing is estimated from surface wind — see how we score.

What are you doing tonight?

The same forecast, weighted for the target. Planetary work barely cares about moonlight; long exposures die on high cloud a visual observer would never notice.

Deep-sky visualPlanetary & lunarWide-field imagingLong exposureMeteor watching

SET UP 01:30 · OBSERVE 02:00–03:00 · 1H · MEAN 57

Darkness and moonlight dominate. Faint fuzzies need a genuinely dark sky more than they need steady air.

0204

CLOUD RETURNS 03:00

SET UP 01:30 · OBSERVE 02:00–03:00 · 1H · MEAN 71

Seeing is everything and moonlight is irrelevant. Bright targets punch through twilight, so darkness barely counts.

0204

CLOUD RETURNS 03:00MOONLIGHT IGNORED FOR THIS TARGET

SET UP 01:30 · OBSERVE 02:00–03:00 · 1H · MEAN 53

Tolerates soft seeing, but high cloud wrecks a wide frame and moonlight raises the background everywhere.

0204

CLOUD RETURNS 03:00

SET UP 01:30 · OBSERVE 02:00–03:00 · 1H · MEAN 42

Needs conditions to hold still for hours. Sustained transparency matters more than any single good hour.

0204

CLOUD RETURNS 03:00

SET UP 01:30 · OBSERVE 02:00–03:00 · 1H · MEAN 59

Naked eye, whole sky. Total cloud and moonlight are the only things that count.

0204

CLOUD RETURNS 03:00

The next week of nights

Tonight · 12 Aug

Good

MOON 0%
02:00–03:00

Tomorrow · 13 Aug

Poor

MOON 1%

Friday · 14 Aug

Poor

MOON 5%

Saturday · 15 Aug

Poor

MOON 8%

Sunday · 16 Aug

Clouded out

MOON 19%

Monday · 17 Aug

Poor

MOON 28%

Tuesday · 18 Aug

Fair

MOON 37%
21:00–22:00

Nearby locations

About this forecast

Conditions for Itsukaichi, Japan are computed from the MET Norway forecast model for these exact coordinates, combined with sun and moon positions we calculate directly. The score weighs cloud cover by layer, atmospheric transparency, estimated seeing, moonlight and how dark the sky actually gets. Read the full method →