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Tonight · Sat, 10 October 2026

Alqueva Dark Sky Reserve stargazing forecast tonight

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

38.200°N 7.500°W ·200 m ·Portugal

93
/100
Excellent conditions
at peak

A genuinely good night — 10 hours of clear, dark sky from 21:00.

Site darkness · peer measure
Threatened dark skyNot multiplied into the conditions score
21.3–21.6 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 Alqueva Dark Sky Reserve, Portugal →Moonless nights →
Tonight in context · local sky & season

Saturn: about 8.7h 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 – 07:00
Window quality
68 / 100 avg
Astronomical dark
21:00 – 07:00
Moon
New moon, 1%
Transparency at peak
0.85
Seeing at peak (est.)
0.98
Visual limit (modelled)
5.5–7.0 mag
Tonight's limiting factor
Nothing much

No single factor is holding this night back. Go out.

The night, hour by hour

Colour = score · Luminance = everything else
Sky state
Shaded = daylight and twilight  ·  unshaded = astronomical dark
54
93
89
84
77
68
53
50
64
57
44
5
Score
BEST WINDOW · 11 H
Low cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
3%
28%
Mid cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
16%
High cloud
0%
0%
0%
0%
2%
11%
26%
58%
59%
20%
34%
62%
76%
88%
Transparency
1.00
1.00
0.85
0.74
0.63
0.56
0.48
0.43
0.36
0.30
0.24
0.18
0.14
0.16
Seeing
1.00
1.00
0.98
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Moon clear
down
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
08
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 Excellent · 93/100
Starting from
100
Cloud
−0
Transparency
−6
Seeing
−0
Moonlight
−0
Darkness
−0
Score
93
CLOUD 0% LOW 0% MID 0% HIGH 0% SUN -24.2° MOON -25.7° / 0% WIND 2 TEMP 20°
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 21:00–06:00 · 9H · MEAN 54

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

19212301030507
ASTRONOMICAL DARK FROM 21:00CLOUD RETURNS 06:00
SET UP 19:30 · OBSERVE 20:00–07:00 · 11H · MEAN 77

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

19212301030507
TWILIGHT BEGINS 07:00MOONLIGHT IGNORED FOR THIS TARGET
SET UP 19:30 · OBSERVE 20:00–03:00 · 7H · MEAN 58

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

19212301030507
SET UP 19:30 · OBSERVE 20:00–02:00 · 6H · MEAN 60

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

19212301030507
CLOUD RETURNS 02:00
SET UP 20:30 · OBSERVE 21:00–06:00 · 9H · MEAN 57

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

19212301030507
ASTRONOMICAL DARK FROM 21:00CLOUD RETURNS 06:00

Deep-sky visual is your current default.

A darker option

Roque de los Muchachos (La Palma)

1,423 km away · Natural-dark sky · 21.7–21.8 mag/arcsec²

30conditions tonight
See the trade-off →

The next week of nights

Tonight · 10 Oct
93
Excellent
MOON 0%
21:00–07:00
Tomorrow · 11 Oct
44
Fair
MOON 2%
00:00–07:00
Monday · 12 Oct
66
Good
MOON 6%
21:00–07:00
Tuesday · 13 Oct
80
Excellent
MOON 12%
01:00–02:00
Wednesday · 14 Oct
83
Excellent
MOON 19%
01:00–02:00
Thursday · 15 Oct
46
Fair
MOON 27%
01:00–02:00
Friday · 16 Oct
40
Fair
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
54
93
89
84
77
68
53
50
64
57
44
5
Score
Low cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
3%
28%
Mid cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
16%
High cloud
0%
0%
0%
0%
2%
11%
26%
58%
59%
20%
34%
62%
76%
88%
Transparency
1.00
1.00
0.85
0.74
0.63
0.56
0.48
0.43
0.36
0.30
0.24
0.18
0.14
0.16
Seeing
1.00
1.00
0.98
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Moon clear
down
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
08

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
33
38
36
34
36
43
43
44
40
40
41
5
Score
Low cloud
0%
0%
0%
0%
0%
0%
0%
0%
1%
4%
9%
30%
41%
48%
Mid cloud
0%
2%
3%
2%
2%
0%
0%
0%
0%
0%
0%
0%
0%
0%
High cloud
48%
59%
94%
97%
98%
90%
68%
66%
59%
67%
59%
19%
23%
57%
Transparency
0.81
0.69
0.63
0.55
0.46
0.38
0.30
0.23
0.18
0.17
0.15
0.14
0.13
0.16
Seeing
0.96
0.95
0.83
0.81
0.80
0.82
0.86
0.91
0.93
0.95
0.97
0.99
1.00
0.97
Moon clear
2%
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
08

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
36
47
41
38
41
40
46
47
49
58
66
11
Score
Low cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Mid cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
High cloud
85%
54%
81%
91%
95%
84%
84%
66%
61%
52%
27%
2%
1%
Transparency
0.79
0.69
0.66
0.59
0.52
0.46
0.38
0.31
0.27
0.24
0.23
0.22
0.20
Seeing
1.00
0.94
0.89
0.91
0.91
0.93
0.96
0.98
0.97
0.94
0.92
0.92
0.94
Moon clear
5%
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
80
8
Score
Low cloud
0%
0%
0%
Mid cloud
0%
0%
0%
High cloud
28%
4%
69%
Transparency
0.93
0.54
0.31
Seeing
1.00
1.00
1.00
Moon clear
10%
down
down
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
83
10
Score
Low cloud
0%
0%
0%
Mid cloud
7%
1%
0%
High cloud
2%
0%
57%
Transparency
0.84
0.58
0.28
Seeing
1.00
1.00
1.00
Moon clear
17%
down
down
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
46
16
Score
Low cloud
0%
0%
0%
Mid cloud
5%
1%
0%
High cloud
59%
81%
0%
Transparency
0.91
0.60
0.43
Seeing
0.97
1.00
1.00
Moon clear
24%
down
down
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
40
15
Score
Low cloud
0%
0%
0%
Mid cloud
3%
1%
9%
High cloud
91%
99%
2%
Transparency
0.96
0.72
0.35
Seeing
1.00
1.00
1.00
Moon clear
33%
down
down
19
01
07

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

About this forecast

Exact-coordinate weather, sky geometry and site context.

Full method →
Sources and scoring details openclose

Conditions for Alqueva Dark Sky Reserve, Portugal 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.