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Tonight · Sat, 10 October 2026

Cardiff stargazing forecast tonight

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

51.480°N 3.180°W ·17 m ·United Kingdom

NearbyPenarthCaerphillyBarryRiscaMore nearby
47
/100
Fair conditions
at peak

Marginal, but there is a 2 hours gap from 21:00.

Site darkness · peer measure
Bright skyNot multiplied into the conditions score
19.3–20.0 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 Cardiff, United Kingdom →Moonless nights →
Tonight in context · local sky & season

October historically: 0.6 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 7.7h 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 – 23:00
Window quality
41 / 100 avg
Astronomical dark
21:00 – 06:00
Moon
New moon, 1%
Transparency at peak
0.34
Seeing at peak (est.)
0.60
Visual limit (modelled)
3.5–5.5 mag
Tonight's limiting factor
Transparency

Transparency 0.34 — haze and water vapour will cost you the faintest targets. What this means →

Also limiting: Thin high cloud. See the guide →

The night, hour by hour

Colour = score · Luminance = everything else
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
35
47
35
23
27
28
27
27
28
28
18
Score
BEST WINDOW · 3 H
Low cloud
8%
3%
6%
9%
2%
1%
0%
1%
0%
2%
12%
20%
Mid cloud
6%
4%
8%
12%
2%
0%
0%
0%
0%
0%
0%
0%
High cloud
30%
45%
71%
99%
98%
98%
100%
100%
100%
100%
100%
100%
Transparency
0.37
0.34
0.27
0.22
0.16
0.11
0.10
0.10
0.10
0.10
0.10
0.10
Seeing
0.62
0.60
0.65
0.69
0.72
0.76
0.77
0.80
0.88
0.97
1.00
1.00
Moon clear
down
down
down
down
down
down
down
down
down
down
down
down
20
21
22
23
00
01
02
03
04
05
06
07
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 · 47/100
Starting from
100
Cloud
−29
Transparency
−19
Seeing
−5
Moonlight
−0
Darkness
−0
Score
47
CLOUD 48% LOW 3% MID 4% HIGH 45% SUN -23.6° MOON -26.4° / 0% WIND 6 TEMP 11°
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.

NO USABLE WINDOW FOR THIS TARGET TONIGHT

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

202200020406
SITE GLOW LIMITS THIS TARGET
SET UP 19:30 · OBSERVE 20:00–23:00 · 3H · MEAN 44

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

202200020406
CLOUD RETURNS 23:00MOONLIGHT IGNORED FOR THIS TARGET
NO USABLE WINDOW FOR THIS TARGET TONIGHT

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

202200020406
SITE GLOW LIMITS THIS TARGET
NO USABLE WINDOW FOR THIS TARGET TONIGHT

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

202200020406
SITE GLOW LIMITS THIS TARGET
NO USABLE WINDOW FOR THIS TARGET TONIGHT

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

202200020406
SITE GLOW LIMITS THIS TARGET

Deep-sky visual is your current default.

A darker option

Bannau Brycheiniog (Brecon Beacons)

48 km away · Brightened sky · 20.9–21.3 mag/arcsec²

30conditions tonight
See the trade-off →

The next week of nights

Tonight · 10 Oct
47
Fair
MOON 1%
21:00–23:00
Tomorrow · 11 Oct
0
Not worth it

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

MOON 2%
Monday · 12 Oct
9
Not worth it

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

MOON 6%
Tuesday · 13 Oct
32
Poor

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

MOON 10%
Wednesday · 14 Oct
22
Poor

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

MOON 19%
Thursday · 15 Oct
0
Not worth it

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

MOON 27%
Friday · 16 Oct
66
Good
MOON 35%
01:00–02:00

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
35
47
35
23
27
28
27
27
28
28
18
Score
Low cloud
8%
3%
6%
9%
2%
1%
0%
1%
0%
2%
12%
20%
Mid cloud
6%
4%
8%
12%
2%
0%
0%
0%
0%
0%
0%
0%
High cloud
30%
45%
71%
99%
98%
98%
100%
100%
100%
100%
100%
100%
Transparency
0.37
0.34
0.27
0.22
0.16
0.11
0.10
0.10
0.10
0.10
0.10
0.10
Seeing
0.62
0.60
0.65
0.69
0.72
0.76
0.77
0.80
0.88
0.97
1.00
1.00
Moon clear
down
down
down
down
down
down
down
down
down
down
down
down
20
21
22
23
00
01
02
03
04
05
06
07

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
11
Score
Low cloud
18%
39%
98%
100%
100%
96%
100%
100%
100%
100%
100%
100%
100%
Mid cloud
47%
20%
84%
100%
100%
100%
100%
100%
100%
100%
100%
63%
20%
High cloud
97%
91%
98%
96%
99%
91%
95%
99%
94%
98%
94%
95%
89%
Transparency
0.23
0.14
0.14
0.17
0.21
0.24
0.10
0.10
0.10
0.10
0.10
0.10
0.10
Seeing
0.67
0.66
0.59
0.61
0.56
0.47
0.47
0.39
0.36
0.39
0.39
0.38
0.39
Moon clear
down
down
down
down
down
down
down
down
down
down
down
down
down
19
20
21
22
23
00
01
02
03
04
05
06
07

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
41
4
9
3
2
Score
Low cloud
81%
13%
94%
100%
100%
100%
84%
95%
100%
99%
96%
100%
97%
Mid cloud
1%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
1%
3%
High cloud
0%
0%
0%
64%
31%
16%
0%
0%
7%
15%
22%
15%
6%
Transparency
0.15
0.12
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.11
0.12
Seeing
0.63
0.78
0.85
0.69
0.62
0.60
0.62
0.65
0.69
0.62
0.59
0.47
0.44
Moon clear
down
down
down
down
down
down
down
down
down
down
down
down
down
19
20
21
22
23
00
01
02
03
04
05
06
07

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
1
32
Score
Low cloud
12%
2%
0%
45%
Mid cloud
0%
0%
0%
0%
High cloud
0%
0%
92%
9%
Transparency
0.37
0.18
0.10
0.10
Seeing
0.30
0.77
1.00
1.00
Moon clear
9%
10%
down
down
13
19
01
07

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
1
22
1
Score
Low cloud
79%
25%
20%
35%
Mid cloud
0%
0%
0%
7%
High cloud
91%
97%
98%
51%
Transparency
0.53
0.37
0.10
0.10
Seeing
0.76
0.82
0.76
0.70
Moon clear
15%
17%
down
down
13
19
01
07

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
1
3
Score
Low cloud
100%
66%
97%
12%
Mid cloud
82%
9%
100%
10%
High cloud
12%
75%
95%
0%
Transparency
0.23
0.10
0.10
0.19
Seeing
0.70
0.69
0.69
0.73
Moon clear
down
24%
down
down
13
19
01
07

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
7
66
5
Score
Low cloud
6%
1%
0%
1%
Mid cloud
5%
0%
2%
0%
High cloud
0%
0%
0%
0%
Transparency
0.65
0.33
0.24
0.20
Seeing
0.66
0.84
0.84
0.90
Moon clear
down
33%
down
down
13
19
01
07

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 →

More nearby locations 8 options · openclose

About this forecast

Exact-coordinate weather, sky geometry and site context.

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

Conditions for Cardiff, United Kingdom 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.