Zion Camp
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Zion Camp clear sky chart from 2005-11-06 to 2024-02-15.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
29%
22653
13%
80597
8%
22568
36%
22568
14%
58051

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 10thNight
14%
752
6%
4416
2%
737
21%
737
4%
3435
January11th to 20thNight
18%
755
7%
4411
4%
740
23%
740
5%
3229
January21st to endNight
22%
830
8%
4688
7%
814
30%
814
7%
3709
February1st to 10thNight
17%
760
10%
2470
4%
760
24%
760
10%
1932
February11th to 20thNight
16%
721
13%
2334
4%
719
27%
719
12%
1752
February21st to endNight
21%
592
14%
1817
6%
592
31%
592
14%
1350
March1st to 10thNight
20%
720
14%
2111
8%
720
27%
720
14%
1600
March11th to 20thNight
21%
720
15%
1980
6%
720
30%
720
17%
1436
March21st to endNight
26%
792
20%
2098
8%
792
35%
792
21%
1463
April1st to 10thNight
21%
720
14%
1800
4%
720
27%
720
18%
1344
April11th to 20thNight
26%
711
18%
1775
6%
711
31%
711
21%
1273
April21st to endNight
27%
583
16%
1663
7%
583
34%
583
17%
1217
May1st to 10thNight
35%
360
18%
1440
16%
360
44%
360
18%
921
May11th to 20thNight
33%
354
21%
1416
18%
354
48%
354
18%
883
May21st to endNight
35%
389
14%
1551
11%
388
49%
388
22%
924
June1st to 10thNight
37%
360
9%
1440
11%
360
43%
360
17%
919
June11th to 20thNight
44%
360
12%
1440
16%
360
51%
360
22%
856
June21st to endNight
44%
360
11%
1440
15%
360
50%
360
19%
923
July1st to 10thNight
52%
350
14%
1400
18%
350
59%
350
26%
787
July11th to 20thNight
51%
348
16%
1392
22%
348
57%
348
23%
819
July21st to endNight
54%
394
15%
1486
16%
372
58%
372
25%
848
August1st to 10thNight
53%
437
15%
1501
14%
435
57%
435
25%
929
August11th to 20thNight
57%
534
18%
1598
14%
534
61%
534
30%
993
August21st to endNight
46%
751
19%
1939
8%
751
50%
751
31%
1271
September1st to 10thNight
46%
720
17%
1800
8%
720
49%
720
31%
1212
September11th to 20thNight
49%
720
20%
1800
12%
720
52%
720
34%
1170
September21st to endNight
42%
720
19%
2055
15%
720
46%
720
26%
1365
October1st to 10thNight
34%
720
18%
2160
12%
720
42%
720
21%
1478
October11th to 20thNight
24%
720
12%
2160
7%
720
32%
720
15%
1625
October21st to endNight
25%
792
12%
2484
7%
792
32%
792
12%
1901
November1st to 10thNight
28%
740
15%
2460
10%
740
35%
740
15%
1730
November11th to 20thNight
22%
760
13%
2660
9%
760
29%
760
12%
1979
November21st to endNight
20%
760
8%
2660
5%
760
25%
760
9%
2108
December1st to 10thNight
16%
760
7%
2660
3%
760
21%
760
6%
2201
December11th to 20thNight
17%
759
10%
3248
5%
759
26%
759
7%
2488
December21st to endNight
14%
829
5%
4844
2%
817
20%
817
4%
3981

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
17%10%48%6%35%45%6%31%
78179
Night
17%12%5%8%6%35%45%6%30%
80894
TransparencyDay
54%411%19%10%1
77884
Night
56%411%19%9%1
80723
SeeingDay
23%15%29%21%9%3
13371
Night
24%12%27%26%10%1
22681

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
16%16%7%12%10%45%43421%
2517
11th to 20thDay
14%13%7%15%10%44445%20%
2520
21st to endDay
15%19%8%13%8%4433419%
2962
February1st to 10thDay
12%15%6%13%9%45%5%5%5%22%
1710
11th to 20thDay
13%15%6%9%8%345%5%6%26%
1609
21st to endDay
18%14%5%8%6%45%45%5%25%
1438
March1st to 10thDay
15%13%5%9%7%36%445%28%
1844
11th to 20thDay
15%12%6%8%7%35%445%30%
1980
21st to endDay
19%9%45%6%34346%38%
2258
April1st to 10thDay
22%12%46%5%3345%6%30%
2160
11th to 20thDay
21%8%37%6%23445%36%
2134
21st to endDay
23%9%47%5%3335%6%33%
2310
May1st to 10thDay
19%9%36%5%35%446%36%
2520
11th to 20thDay
18%7%36%6%3445%6%37%
2478
21st to endDay
15%7%36%6%45%5%6%8%37%
2725
June1st to 10thDay
20%8%37%5%45%5%6%6%31%
2520
11th to 20thDay
16%6%26%435%5%5%7%40%
2520
21st to endDay
16%7%36%6%46%6%6%8%33%
2520
July1st to 10thDay
12%5%25%5%36%5%8%8%40%
2520
11th to 20thDay
12%6%35%5%36%6%7%9%39%
2520
21st to endDay
11%6%36%5%45%5%7%10%39%
2744
August1st to 10thDay
11%6%36%7%46%6%6%7%38%
2424
11th to 20thDay
13%6%36%6%46%5%5%8%39%
2303
21st to endDay
13%6%26%5%35%6%7%10%36%
2398
September1st to 10thDay
14%5%36%6%35%45%8%42%
2160
11th to 20thDay
15%6%25%5%35%45%6%43%
2160
21st to endDay
18%7%36%6%345%6%7%36%
1901
October1st to 10thDay
20%7%37%6%44446%34%
1800
11th to 20thDay
24%10%47%7%345%46%26%
1800
21st to endDay
27%10%48%6%3445%5%25%
1872
November1st to 10thDay
16%11%37%6%345%5%6%34%
1614
11th to 20thDay
19%13%38%7%45%6%46%24%
1520
21st to endDay
24%15%6%8%8%45%44417%
1520
December1st to 10thDay
21%17%6%12%7%5%4345%16%
1520
11th to 20thDay
20%16%5%9%7%345%46%21%
1906
21st to endDay
27%19%6%13%5%3222318%
2772
January1st to 10thNight
17%17%8%12%7%45%44417%
4429
11th to 20thNight
13%12%5%13%9%46%5%6%6%20%
4440
21st to endNight
15%20%7%10%8%5%444420%
4692
February1st to 10thNight
13%14%6%13%9%46%5%46%21%
2470
11th to 20thNight
13%15%7%10%7%45%445%27%
2332
21st to endNight
14%13%5%10%8%35%446%28%
1817
March1st to 10thNight
17%14%5%6%7%46%445%28%
2101
11th to 20thNight
15%14%5%8%5%3445%5%32%
1979
21st to endNight
16%9%47%6%34445%38%
2098
April1st to 10thNight
20%11%47%6%34346%31%
1800
11th to 20thNight
20%9%36%6%3445%6%35%
1775
21st to endNight
21%10%48%5%35%35%5%31%
1663
May1st to 10thNight
21%8%36%43445%7%36%
1440
11th to 20thNight
19%7%25%5%3445%7%39%
1415
21st to endNight
13%5%345%35%5%6%8%44%
1550
June1st to 10thNight
17%7%36%6%35%5%6%7%35%
1440
11th to 20thNight
14%5%25%5%345%5%7%44%
1440
21st to endNight
17%5%36%6%4446%8%37%
1440
July1st to 10thNight
11%4345%36%6%5%9%44%
1440
11th to 20thNight
12%6%25%435%6%6%8%42%
1440
21st to endNight
9%5%35%6%45%6%7%10%41%
1574
August1st to 10thNight
10%5%25%6%45%6%6%8%42%
1511
11th to 20thNight
10%5%36%6%35%6%5%8%45%
1598
21st to endNight
12%5%35%6%345%6%7%44%
1939
September1st to 10thNight
11%6%36%6%35%5%5%7%45%
1800
11th to 20thNight
16%5%25%33335%7%47%
1800
21st to endNight
18%7%26%5%33347%42%
2055
October1st to 10thNight
21%7%26%5%3445%5%39%
2160
11th to 20thNight
23%11%26%6%45%445%29%
2160
21st to endNight
24%13%36%5%45%5%45%26%
2484
November1st to 10thNight
19%10%46%5%3445%6%32%
2460
11th to 20thNight
19%11%48%6%45%447%26%
2660
21st to endNight
22%15%5%10%7%3445%5%20%
2660
December1st to 10thNight
21%18%7%9%7%45%445%16%
2660
11th to 20thNight
21%16%6%8%6%34345%24%
3288
21st to endNight
28%18%6%11%5%3433317%
4884

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
70%312%9%6%
2518
11th to 20thDay
68%311%12%6%
2520
21st to endDay
72%39%10%5%1
2962
February1st to 10thDay
64%49%17%5%1
1710
11th to 20thDay
59%412%15%10%1
1618
21st to endDay
61%310%15%10%1
1438
March1st to 10thDay
59%39%17%10%1
1847
11th to 20thDay
57%311%16%11%2
1980
21st to endDay
50%39%21%13%5%
2258
April1st to 10thDay
56%37%19%12%3
2160
11th to 20thDay
52%37%22%15%2
2134
21st to endDay
55%27%17%14%4
2310
May1st to 10thDay
50%48%20%14%4
2520
11th to 20thDay
48%48%21%17%2
2482
21st to endDay
45%5%12%21%14%3
2725
June1st to 10thDay
53%410%20%12%1
2520
11th to 20thDay
43%5%12%24%14%2
2520
21st to endDay
48%6%14%20%11%1
2520
July1st to 10thDay
39%5%13%27%15%1
2450
11th to 20thDay
40%6%16%25%12%1
2445
21st to endDay
41%6%16%27%9%
2591
August1st to 10thDay
44%6%15%25%10%
2410
11th to 20thDay
43%6%17%26%8%1
2303
21st to endDay
42%6%15%25%11%1
2398
September1st to 10thDay
40%6%14%29%11%
2160
11th to 20thDay
41%5%11%31%11%1
2160
21st to endDay
47%6%14%25%8%
1901
October1st to 10thDay
50%5%12%22%11%1
1800
11th to 20thDay
60%5%14%16%41
1800
21st to endDay
61%413%16%5%1
1872
November1st to 10thDay
51%415%22%7%
1614
11th to 20thDay
62%5%13%13%7%1
1520
21st to endDay
71%5%10%9%5%
1520
December1st to 10thDay
73%410%10%4
1520
11th to 20thDay
66%410%13%7%
1906
21st to endDay
74%27%14%3
2772
January1st to 10thNight
71%314%9%3
4429
11th to 20thNight
65%315%13%41
4440
21st to endNight
70%310%11%6%
4692
February1st to 10thNight
65%49%15%6%1
2470
11th to 20thNight
61%39%19%7%1
2334
21st to endNight
59%310%18%10%1
1817
March1st to 10thNight
59%48%17%9%2
2111
11th to 20thNight
54%311%17%12%2
1980
21st to endNight
48%48%21%15%5%
2098
April1st to 10thNight
55%49%18%12%2
1800
11th to 20thNight
50%47%22%15%2
1775
21st to endNight
56%36%16%16%3
1663
May1st to 10thNight
47%46%20%17%5%
1440
11th to 20thNight
46%37%23%17%4
1416
21st to endNight
40%5%13%22%17%3
1551
June1st to 10thNight
47%5%14%25%8%1
1440
11th to 20thNight
40%5%12%26%15%2
1440
21st to endNight
46%6%13%21%13%1
1440
July1st to 10thNight
35%6%15%24%18%2
1400
11th to 20thNight
40%5%12%30%13%
1392
21st to endNight
36%6%15%30%13%
1486
August1st to 10thNight
38%8%16%24%14%
1501
11th to 20thNight
36%6%18%28%11%
1598
21st to endNight
40%5%15%29%11%1
1939
September1st to 10thNight
40%6%10%29%14%
1800
11th to 20thNight
37%5%15%33%9%1
1800
21st to endNight
44%414%29%9%
2055
October1st to 10thNight
47%6%11%24%13%
2160
11th to 20thNight
57%5%11%19%7%
2160
21st to endNight
60%5%12%15%7%
2484
November1st to 10thNight
52%5%14%20%8%
2460
11th to 20thNight
59%5%12%15%8%1
2660
21st to endNight
66%5%12%14%3
2660
December1st to 10thNight
72%48%12%4
2660
11th to 20thNight
65%49%15%7%
3288
21st to endNight
74%37%12%4
4884

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
24%18%32%21%41
180
11th to 20thDay
29%19%31%17%31
180
21st to endDay
20%19%34%21%6%
252
February1st to 10thDay
29%21%33%12%4
270
11th to 20thDay
29%23%38%10%
252
21st to endDay
33%22%30%14%1
304
March1st to 10thDay
26%20%34%17%4
420
11th to 20thDay
26%20%31%18%5%
420
21st to endDay
29%19%28%17%6%1
462
April1st to 10thDay
34%18%26%15%6%1
420
11th to 20thDay
35%16%21%16%9%4
412
21st to endDay
29%20%27%16%6%1
420
May1st to 10thDay
28%14%26%21%8%2
423
11th to 20thDay
21%18%32%18%9%3
447
21st to endDay
21%14%31%22%9%2
485
June1st to 10thDay
25%12%32%22%8%1
450
11th to 20thDay
18%14%27%24%13%3
450
21st to endDay
19%12%30%22%14%2
450
July1st to 10thDay
12%8%25%38%13%3
445
11th to 20thDay
13%9%34%26%14%4
444
21st to endDay
13%8%32%31%14%3
488
August1st to 10thDay
15%8%26%29%17%6%
446
11th to 20thDay
15%6%24%29%17%9%
439
21st to endDay
15%12%26%26%15%7%
495
September1st to 10thDay
17%8%30%23%14%8%
450
11th to 20thDay
18%10%23%22%18%9%
450
21st to endDay
20%13%28%20%13%7%
450
October1st to 10thDay
24%15%23%19%15%4
450
11th to 20thDay
30%19%28%15%7%1
450
21st to endDay
32%17%23%21%5%1
441
November1st to 10thDay
28%14%34%16%8%1
308
11th to 20thDay
26%24%32%11%6%1
180
21st to endDay
34%21%29%10%42
180
December1st to 10thDay
31%13%40%13%21
180
11th to 20thDay
31%24%31%9%31
180
21st to endDay
35%16%31%13%31
198
January1st to 10thNight
31%14%31%20%5%
760
11th to 20thNight
31%14%26%22%7%1
760
21st to endNight
19%13%34%26%7%
836
February1st to 10thNight
20%18%34%23%41
760
11th to 20thNight
23%16%36%21%31
722
21st to endNight
22%18%30%25%4
592
March1st to 10thNight
24%16%31%24%5%
720
11th to 20thNight
24%16%32%21%6%1
720
21st to endNight
23%15%30%22%9%
792
April1st to 10thNight
28%13%30%23%6%
720
11th to 20thNight
25%15%28%22%9%
711
21st to endNight
25%14%28%25%8%1
583
May1st to 10thNight
23%8%28%31%10%1
360
11th to 20thNight
25%8%27%31%8%
354
21st to endNight
16%5%37%31%11%
389
June1st to 10thNight
19%9%26%37%8%1
360
11th to 20thNight
18%7%25%35%14%1
360
21st to endNight
19%7%22%40%12%1
360
July1st to 10thNight
10%426%43%17%
350
11th to 20thNight
14%5%22%38%20%
348
21st to endNight
11%422%46%16%1
394
August1st to 10thNight
12%320%39%24%1
437
11th to 20thNight
13%316%38%25%4
534
21st to endNight
15%6%25%34%19%2
751
September1st to 10thNight
15%7%24%33%19%2
720
11th to 20thNight
19%6%19%33%20%3
720
21st to endNight
21%9%22%27%19%2
720
October1st to 10thNight
24%10%26%24%14%2
720
11th to 20thNight
29%11%29%22%9%1
720
21st to endNight
31%13%25%24%6%1
792
November1st to 10thNight
25%14%26%26%8%1
740
11th to 20thNight
28%14%30%18%9%1
760
21st to endNight
33%15%23%22%6%
760
December1st to 10thNight
32%16%29%18%5%
760
11th to 20thNight
29%18%26%21%5%1
760
21st to endNight
35%14%27%20%4
836
Page generated at 2024-02-12 06:35:37. Version ac07

Copyright 2024 Attilla Danko


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