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Tonight · Sat, 10 October 2026

Mauna Kea stargazing forecast tonight

Hourly clear-sky conditions for observing: cloud by layer, transparency, estimated seeing, moonlight and true astronomical darkness.

19.821°N 155.468°W ·4207 m ·Hawaii, United States

NearbyHilo
49
/100
Fair conditions
at peak

Marginal, but there is a 3 hours gap from 03:00.

Site darkness · peer measure
Natural-dark skyNot multiplied into the conditions score
21.9–21.9 mag/arcsec²

The score describes tonight’s conditions. Site darkness helps you choose what to observe.

See target outlook ↓Planet observing times →
Best months at Mauna Kea, Hawaii →Moonless nights →
Tonight in context · local sky & season

October historically: 3.6 qualifying nights/month on average (2005–2024). Regional cloud and darkness history, not tonight’s probability or a comparison with the conditions score.

A qualifying historical night has at least 3 hours of astronomical darkness and mean nighttime cloud ≤30%. This does not measure steady air or target visibility. Seasonal history →

Saturn: about 9.3h above 20° during this observing night’s darkness. Longest sampled dark-time opportunity among our four planet targets; not a weather ranking. Planet times →

Position calculations use roughly 20-minute samples. Clouds, skyglow and local obstructions still matter. Milky Way timing →

Best window
03:00 – 06:00
Window quality
42 / 100 avg
Astronomical dark
20:00 – 06:00
Moon
Waxing crescent, 1%
Transparency at peak
0.54
Seeing at peak (est.)
0.86
Visual limit (modelled)
6.0–7.0 mag
Tonight's limiting factor
Transparency

Transparency 0.54 — haze and water vapour will cost you the faintest targets. What this means →

The night, hour by hour

Colour = score · Luminance = everything else
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
3
7
13
19
22
25
29
35
41
49
Score
BEST WINDOW · 4 H
Low cloud
91%
99%
84%
73%
59%
52%
48%
45%
40%
31%
27%
21%
17%
Mid cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
High cloud
27%
1%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Transparency
0.16
0.15
0.17
0.21
0.27
0.31
0.34
0.37
0.39
0.42
0.48
0.54
0.59
Seeing
0.82
0.88
0.88
0.87
0.87
0.87
0.89
0.87
0.86
0.86
0.86
0.86
0.85
Moon clear
1%
down
down
down
down
down
down
down
down
down
down
down
down
18
19
20
21
22
23
00
01
02
03
04
05
06
Inspect

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

Score inspectorWhy this hour scored what it did Open peakClose
05 Fair · 49/100
Starting from
100
Cloud
−38
Transparency
−11
Seeing
−2
Moonlight
−0
Darkness
−0
Score
49
CLOUD 21% LOW 21% MID 0% HIGH 0% SUN -18.6° MOON -31.2° / 1% WIND 3 TEMP -2°
Excellent 75+ Good 55+ Fair 35+ Poor 15+ Not worth it Seeing is estimated from surface wind — see how we score.

What can you actually do tonight?

This is GoodSeeing’s decision layer: the same forecast is weighted for your target and site darkness. Planetary work barely cares about moonlight; long exposures can fail on high cloud a visual observer would barely notice. Your choice is remembered on this device and becomes the default for new alert rules.

SET UP 02:30 · OBSERVE 03:00–06:00 · 3H · MEAN 42

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

18202200020406
TWILIGHT BEGINS 06:00
SET UP 02:30 · OBSERVE 03:00–06:00 · 3H · MEAN 46

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

18202200020406
TWILIGHT BEGINS 06:00MOONLIGHT IGNORED FOR THIS TARGET
SET UP 03:30 · OBSERVE 04:00–06:00 · 2H · MEAN 44

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

18202200020406
TWILIGHT BEGINS 06:00
SET UP 04:30 · OBSERVE 05:00–06:00 · 1H · MEAN 36

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

18202200020406
TWILIGHT BEGINS 06:00
SET UP 03:30 · OBSERVE 04:00–06:00 · 2H · MEAN 43

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

18202200020406
TWILIGHT BEGINS 06:00

Deep-sky visual is your current default.

A darker option

Big Bend National Park

5,342 km away · Natural-dark sky · 21.9–21.9 mag/arcsec²

86conditions tonight
See the trade-off →
Latest verified night · 2026-10-08

Prediction, meet observation.

All comparisons →
3 matches6 discrepanciesSatellite saw 55.2 points less cloud.
HIMAWARI cloud mask · ~13h reference6 of 9 sampled hours diverged.Cloud only · 9 astronomically dark hours

Recent cloud comparisons · 30 recorded nights →

The next week of nights

Tonight · 10 Oct
49
Fair
MOON 1%
03:00–06:00
Tomorrow · 11 Oct
68
Good
MOON 4%
03:00–06:00
Monday · 12 Oct
17
Poor

Cloud or fog is the strongest score limit at the best sampled time.

MOON 7%
Tuesday · 13 Oct
59
Good
MOON 15%
02:00–03:00
Wednesday · 14 Oct
61
Good
MOON 22%
02:00–03:00
Thursday · 15 Oct
71
Good
MOON 31%
02:00–03:00
Friday · 16 Oct
71
Good
MOON 40%
02:00–03:00

Open a night for its forecast times. Later forecasts may have wider time steps; missing hours are not interpolated.

Tonight · 10 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
3
7
13
19
22
25
29
35
41
49
Score
Low cloud
91%
99%
84%
73%
59%
52%
48%
45%
40%
31%
27%
21%
17%
Mid cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
High cloud
27%
1%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Transparency
0.16
0.15
0.17
0.21
0.27
0.31
0.34
0.37
0.39
0.42
0.48
0.54
0.59
Seeing
0.82
0.88
0.88
0.87
0.87
0.87
0.89
0.87
0.86
0.86
0.86
0.86
0.85
Moon clear
1%
down
down
down
down
down
down
down
down
down
down
down
down
18
19
20
21
22
23
00
01
02
03
04
05
06

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

Tomorrow · 11 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
1
2
2
2
2
10
18
32
42
55
68
Score
Low cloud
85%
84%
84%
84%
84%
84%
67%
51%
34%
22%
13%
6%
2%
Mid cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
High cloud
2%
2%
0%
0%
2%
0%
0%
0%
5%
13%
9%
1%
0%
Transparency
0.15
0.16
0.16
0.18
0.21
0.27
0.33
0.34
0.37
0.38
0.39
0.44
0.49
Seeing
0.88
0.96
0.99
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
0.99
0.90
Moon clear
3%
down
down
down
down
down
down
down
down
down
down
down
down
18
19
20
21
22
23
00
01
02
03
04
05
06

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

Monday · 12 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
12
17
Score
Low cloud
48%
59%
61%
100%
100%
Mid cloud
5%
2%
2%
21%
100%
High cloud
0%
0%
0%
0%
0%
Transparency
0.21
0.21
0.21
0.24
0.24
Seeing
0.91
0.88
0.87
1.00
1.00
Moon clear
7%
7%
down
down
down
18
19
20
02
08

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

Tuesday · 13 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
6
59
Score
Low cloud
99%
90%
15%
0%
Mid cloud
100%
9%
0%
0%
High cloud
0%
0%
0%
0%
Transparency
0.30
0.19
0.23
0.54
Seeing
1.00
1.00
1.00
1.00
Moon clear
12%
13%
down
down
14
20
02
08

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

Wednesday · 14 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
61
Score
Low cloud
62%
100%
23%
4%
Mid cloud
0%
0%
0%
0%
High cloud
0%
0%
0%
0%
Transparency
0.32
0.17
0.49
0.91
Seeing
0.89
1.00
1.00
1.00
Moon clear
19%
21%
down
down
14
20
02
08

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

Thursday · 15 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
71
Score
Low cloud
52%
99%
8%
0%
Mid cloud
0%
0%
0%
0%
High cloud
0%
0%
0%
0%
Transparency
0.30
0.15
0.44
0.56
Seeing
0.93
1.00
1.00
1.00
Moon clear
27%
29%
down
down
14
20
02
08

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

Friday · 16 Oct · forecast times
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
35
71
Score
Low cloud
90%
41%
5%
2%
Mid cloud
0%
0%
0%
0%
High cloud
0%
0%
0%
0%
Transparency
0.41
0.21
0.36
0.71
Seeing
0.89
1.00
1.00
1.00
Moon clear
35%
37%
down
down
14
20
02
08

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

Planning a trip?

Compare the next eight weekends → · Best months to visit → · Moonless nights →

About this forecast

Exact-coordinate weather, sky geometry and site context.

Full method →20-year baseline →
Sources and scoring details openclose

Conditions for Mauna Kea, Hawaii, United States 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 astronomical twilight. Site darkness is shown separately, then used only where artificial skyglow physically changes moon contrast, haze scattering, visual limits and target suitability.