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Tonight · Sat, 10 October 2026

Hilo stargazing forecast tonight

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

19.730°N 155.091°W ·30 m ·Hawaii, United States

NearbyMauna Kea
46
/100
Fair conditions
at peak

Marginal, but there is a 1 hour gap from 21:00.

Site darkness · peer measure
Threatened dark skyNot multiplied into the conditions score
21.5–21.7 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 Hilo, Hawaii →Moonless nights →
Tonight in context · local sky & season

October historically: 4.8 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
21:00 – 22:00
Window quality
46 / 100 avg
Astronomical dark
20:00 – 06:00
Moon
Waxing crescent, 1%
Transparency at peak
0.27
Seeing at peak (est.)
0.96
Visual limit (modelled)
5.5–6.5 mag
Tonight's limiting factor
Transparency

Transparency 0.27 — haze and water vapour will cost you the faintest targets. What this means →

Also limiting: Low cloud. See the guide →

The night, hour by hour

Colour = score · Luminance = everything else
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
23
34
46
26
4
1
34
Score
BEST WINDOW · 2 H
Low cloud
36%
45%
46%
28%
56%
93%
100%
100%
100%
100%
98%
46%
47%
Mid cloud
14%
15%
9%
4%
10%
13%
16%
14%
16%
8%
6%
7%
7%
High cloud
16%
7%
0%
9%
4%
0%
0%
0%
0%
0%
0%
0%
0%
Transparency
0.26
0.25
0.26
0.27
0.26
0.10
0.10
0.22
0.22
0.21
0.19
0.20
0.23
Seeing
0.96
0.98
0.97
0.96
0.92
0.91
0.91
0.88
0.87
0.94
0.98
0.92
0.86
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
21 Fair · 46/100
Starting from
100
Cloud
−35
Transparency
−19
Seeing
−0
Moonlight
−0
Darkness
−0
Score
46
CLOUD 36% LOW 28% MID 4% HIGH 9% SUN -42.8° MOON -38.3° / 1% WIND 2 TEMP 24°
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 20:30 · OBSERVE 21:00–22:00 · 1H · MEAN 38

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

18202200020406
CLOUD RETURNS 22:00
SET UP 18:30 · OBSERVE 19:00–22:00 · 3H · MEAN 44

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

18202200020406
CLOUD RETURNS 22:00MOONLIGHT IGNORED FOR THIS TARGET
SET UP 20:30 · OBSERVE 21:00–22:00 · 1H · MEAN 37

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

18202200020406
CLOUD RETURNS 22:00
NO USABLE WINDOW FOR THIS TARGET TONIGHT

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

18202200020406
CONDITIONS STAY BELOW THE USABLE THRESHOLD
SET UP 20:30 · OBSERVE 21:00–22:00 · 1H · MEAN 39

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

18202200020406
CLOUD RETURNS 22:00

Deep-sky visual is your current default.

A darker option

Mauna Kea

41 km away · Natural-dark sky · 21.9–21.9 mag/arcsec²

49conditions tonight
See the trade-off →

The next week of nights

Tonight · 10 Oct
46
Fair
MOON 1%
21:00–22:00
Tomorrow · 11 Oct
76
Excellent
MOON 4%
01:00–06:00
Monday · 12 Oct
11
Not worth it

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

MOON 7%
Tuesday · 13 Oct
45
Fair
MOON 15%
02:00–03:00
Wednesday · 14 Oct
49
Fair
MOON 22%
02:00–03:00
Thursday · 15 Oct
54
Fair
MOON 31%
02:00–03:00
Friday · 16 Oct
41
Fair
MOON 40%
20:00–21:00

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
23
34
46
26
4
1
34
Score
Low cloud
36%
45%
46%
28%
56%
93%
100%
100%
100%
100%
98%
46%
47%
Mid cloud
14%
15%
9%
4%
10%
13%
16%
14%
16%
8%
6%
7%
7%
High cloud
16%
7%
0%
9%
4%
0%
0%
0%
0%
0%
0%
0%
0%
Transparency
0.26
0.25
0.26
0.27
0.26
0.10
0.10
0.22
0.22
0.21
0.19
0.20
0.23
Seeing
0.96
0.98
0.97
0.96
0.92
0.91
0.91
0.88
0.87
0.94
0.98
0.92
0.86
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
42
57
47
16
21
31
42
52
63
71
76
Score
Low cloud
10%
6%
4%
5%
10%
5%
2%
2%
0%
0%
1%
1%
1%
Mid cloud
27%
24%
26%
42%
85%
80%
65%
48%
36%
23%
13%
6%
5%
High cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Transparency
0.50
0.51
0.50
0.51
0.49
0.50
0.48
0.47
0.49
0.52
0.57
0.58
0.58
Seeing
0.95
0.87
0.88
0.92
0.90
0.91
0.92
0.91
0.89
0.89
0.89
0.85
0.88
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
11
Score
Low cloud
100%
100%
79%
100%
9%
Mid cloud
23%
27%
23%
100%
80%
High cloud
0%
0%
0%
0%
0%
Transparency
0.10
0.10
0.18
0.17
0.28
Seeing
0.85
0.97
0.98
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
28
45
Score
Low cloud
77%
52%
32%
6%
Mid cloud
23%
19%
4%
0%
High cloud
0%
0%
0%
0%
Transparency
0.52
0.27
0.26
0.48
Seeing
0.94
1.00
0.92
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
23
49
Score
Low cloud
42%
65%
25%
28%
Mid cloud
58%
6%
9%
12%
High cloud
0%
0%
0%
0%
Transparency
0.47
0.29
0.26
0.39
Seeing
0.93
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
29
54
Score
Low cloud
44%
29%
18%
32%
Mid cloud
58%
38%
2%
6%
High cloud
0%
0%
0%
0%
Transparency
0.35
0.19
0.20
0.37
Seeing
1.00
0.92
0.93
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
41
36
Score
Low cloud
23%
29%
50%
7%
Mid cloud
15%
7%
2%
4%
High cloud
0%
0%
0%
0%
Transparency
0.41
0.25
0.37
0.52
Seeing
1.00
0.96
0.95
0.96
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 Hilo, 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.