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Al Jumūm

21.619° N   39.697° E  ·  208 M
46 /100
PEAK
Marginal, but there is a 1 hour gap from 04:00.
BEST WINDOW 04:00–05:00 · ASTRO DARK 21:00–05:00 · MOON 0%
Transparency
1.00
Seeing
0.77
Cloud
73%
Moon
0%

Fair tonight

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

Sky state
Lighter = daylight and twilight  ·  unshaded = astronomical dark
Score
21
22
23
00
01
02
03
04
05
06
13
19
21
7
5
4
17
46
16
0
BEST WINDOW
Low cloud
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
Mid cloud
77%
56%
81%
95%
98%
99%
69%
18%
49%
94%
High cloud
100%
100%
20%
75%
95%
98%
88%
70%
94%
100%
Transparency
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Seeing
0.77
0.48
0.43
0.35
0.45
0.35
0.51
0.57
0.63
0.80
Moon clear
down
down
down
down
down
down
down
down
down
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
21 Clouded out · 13/100
Starting from
100
Cloud
−86
Transparency
−0
Seeing
−1
Moonlight
−0
Darkness
−0
Score
13
CLOUD 100% LOW 0% MID 77% HIGH 100% SUN -27.5° MOON -25.7° / 0% WIND 4 TEMP 36°
Excellent 75+ Good 55+ Fair 35+ Poor 15+ Not worth it Seeing is estimated from surface wind — see how we score.
Tonight's limiting factor
When a clear gap is worth driving for

Ask how long the gap is relative to your setup time and your exposure length. A two-hour gap is a real session for a visual observer and close to worthless for someone doing four-minute subs on a target that needs three hours.

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.

SET UP 03:30 · OBSERVE 04:00–05:00 · 1H · MEAN 46

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

2123010305
HIGH CLOUD CLEARS 04:00CLOUD RETURNS 05:00
SET UP 03:30 · OBSERVE 04:00–05:00 · 1H · MEAN 38

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

2123010305
HIGH CLOUD CLEARS 04:00CLOUD RETURNS 05:00MOONLIGHT IGNORED FOR THIS TARGET
SET UP 03:30 · OBSERVE 04:00–05:00 · 1H · MEAN 40

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

2123010305
HIGH CLOUD CLEARS 04:00CLOUD RETURNS 05:00
NO USABLE WINDOW FOR THIS TARGET TONIGHT

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

2123010305
CLOUD NEVER DROPS BELOW 73%
SET UP 03:30 · OBSERVE 04:00–05:00 · 1H · MEAN 41

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

2123010305
HIGH CLOUD CLEARS 04:00CLOUD RETURNS 05:00
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The next week of nights

Tonight · 12 Aug
46
Fair
MOON 0%
04:00–05:00
Tomorrow · 13 Aug
84
Excellent
MOON 2%
21:00–00:00
Friday · 14 Aug
91
Excellent
MOON 6%
21:00–05:00
Saturday · 15 Aug
90
Excellent
MOON 13%
21:00–22:00
Sunday · 16 Aug
100
Excellent
MOON 21%
03:00–04:00
Monday · 17 Aug
100
Excellent
MOON 30%
03:00–04:00
Tuesday · 18 Aug
98
Excellent
MOON 39%
03:00–04:00
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Nearby locations

About this forecast

Conditions for Al Jumūm, Saudi Arabia 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 →