Delta Rocky Crest Resort
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Delta Rocky Crest Resort clear sky chart from 2005-11-06 to 2024-01-12.

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
28%
23006
13%
74627
8%
22959
34%
22959
15%
54674

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
12%
948
7%
2838
2%
946
17%
946
7%
2421
January11th to 20thNight
14%
746
8%
2474
4%
746
19%
746
7%
2033
January21st to endNight
20%
792
11%
2574
7%
792
26%
792
11%
2024
February1st to 10thNight
14%
720
8%
2340
2%
720
21%
720
8%
1909
February11th to 20thNight
18%
701
12%
2275
5%
700
27%
700
11%
1736
February21st to endNight
19%
592
10%
1893
4%
592
26%
592
9%
1481
March1st to 10thNight
20%
720
15%
1992
6%
720
28%
720
17%
1450
March11th to 20thNight
22%
720
16%
1980
7%
720
30%
720
17%
1439
March21st to endNight
29%
792
18%
2178
9%
792
36%
792
21%
1519
April1st to 10thNight
22%
720
14%
1836
5%
720
27%
720
18%
1386
April11th to 20thNight
29%
609
19%
1673
9%
609
35%
609
20%
1180
April21st to endNight
30%
540
15%
1620
8%
540
36%
540
17%
1180
May1st to 10thNight
38%
516
16%
1596
12%
516
44%
516
23%
1047
May11th to 20thNight
36%
354
20%
1416
18%
354
48%
354
21%
837
May21st to endNight
43%
388
14%
1551
13%
388
53%
388
24%
872
June1st to 10thNight
39%
360
11%
1389
11%
360
47%
360
18%
880
June11th to 20thNight
47%
360
16%
1260
16%
360
55%
360
26%
741
June21st to endNight
45%
360
13%
1260
13%
360
50%
360
22%
792
July1st to 10thNight
58%
350
18%
1225
20%
350
64%
350
35%
661
July11th to 20thNight
49%
348
16%
1303
20%
348
56%
348
25%
764
July21st to endNight
52%
505
15%
1591
14%
477
55%
477
27%
945
August1st to 10thNight
55%
537
16%
1600
14%
534
59%
534
31%
958
August11th to 20thNight
58%
534
17%
1598
12%
534
63%
534
30%
997
August21st to endNight
47%
637
18%
1825
9%
637
51%
637
28%
1185
September1st to 10thNight
48%
720
16%
1800
7%
720
51%
720
32%
1181
September11th to 20thNight
48%
720
21%
1912
13%
720
51%
720
33%
1217
September21st to endNight
44%
720
21%
2008
14%
720
48%
720
25%
1373
October1st to 10thNight
32%
720
15%
2160
10%
720
39%
720
19%
1531
October11th to 20thNight
23%
720
11%
2160
6%
720
30%
720
12%
1686
October21st to endNight
18%
792
11%
2385
6%
792
24%
792
10%
1901
November1st to 10thNight
25%
740
14%
2542
11%
740
31%
740
14%
1822
November11th to 20thNight
18%
760
12%
2660
7%
760
25%
760
11%
1992
November21st to endNight
13%
760
7%
2660
4%
760
18%
760
7%
2154
December1st to 10thNight
12%
760
6%
2660
3%
760
16%
760
5%
2263
December11th to 20thNight
10%
760
8%
3281
3%
759
18%
759
6%
2712
December21st to endNight
10%
985
4%
5112
1%
973
14%
973
3%
4405

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
18%11%47%6%35%45%6%32%
74853
Night
18%13%5%8%6%3445%6%30%
74833
TransparencyDay
52%6%11%20%10%1
74555
Night
55%5%11%18%10%1
74666
SeeingDay
23%14%31%20%9%3
13843
Night
24%12%28%25%10%1
23018

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
17%21%8%12%5%4344419%
1328
11th to 20thDay
16%22%9%9%6%34245%21%
1507
21st to endDay
14%17%8%12%6%45%345%21%
1782
February1st to 10thDay
14%19%8%13%9%34435%19%
1620
11th to 20thDay
14%16%7%12%7%34345%26%
1573
21st to endDay
16%18%6%12%7%4444322%
1361
March1st to 10thDay
15%13%5%8%6%45%446%30%
1963
11th to 20thDay
12%14%6%9%7%44346%32%
1980
21st to endDay
18%10%46%5%345%46%35%
2178
April1st to 10thDay
21%13%5%6%5%2445%6%29%
2124
11th to 20thDay
21%10%35%5%24346%36%
2251
21st to endDay
22%11%46%424445%34%
2340
May1st to 10thDay
20%8%36%5%35%5%5%7%34%
2362
11th to 20thDay
16%8%36%5%35%35%7%39%
2478
21st to endDay
14%5%35%5%35%5%6%7%43%
2725
June1st to 10thDay
19%6%35%6%3445%7%38%
2565
11th to 20thDay
14%6%25%6%35%5%6%9%40%
2700
21st to endDay
19%7%35%6%2446%9%35%
2700
July1st to 10thDay
12%4245%36%5%6%8%45%
2700
11th to 20thDay
13%6%35%5%35%45%9%42%
2611
21st to endDay
14%5%25%6%35%5%6%7%41%
2630
August1st to 10thDay
13%6%35%5%35%46%8%42%
2327
11th to 20thDay
14%5%26%5%345%6%8%41%
2303
21st to endDay
15%6%36%5%35%5%7%7%38%
2512
September1st to 10thDay
14%6%36%435%6%6%8%41%
2160
11th to 20thDay
17%5%25%435%46%7%43%
2046
21st to endDay
21%8%35%6%34446%35%
1951
October1st to 10thDay
23%8%36%6%35%447%33%
1800
11th to 20thDay
29%10%46%5%35%45%6%22%
1800
21st to endDay
31%13%47%5%2445%421%
1967
November1st to 10thDay
20%14%46%5%345%5%8%26%
1533
11th to 20thDay
20%15%5%7%6%45%5%5%5%22%
1520
21st to endDay
24%20%47%6%45%445%18%
1520
December1st to 10thDay
18%25%7%8%6%35%335%18%
1520
11th to 20thDay
20%24%6%10%5%2333421%
1906
21st to endDay
27%20%6%9%7%3433414%
2510
January1st to 10thNight
18%19%8%12%8%4434416%
2838
11th to 20thNight
20%19%8%9%6%3443420%
2474
21st to endNight
13%14%8%12%8%3445%5%23%
2574
February1st to 10thNight
14%18%7%11%8%45%45%5%18%
2340
11th to 20thNight
14%14%8%11%7%35%445%25%
2273
21st to endNight
16%17%6%9%7%35%5%4424%
1893
March1st to 10thNight
14%11%5%9%7%34346%35%
1982
11th to 20thNight
14%12%5%8%6%345%45%34%
1979
21st to endNight
16%10%47%5%24346%38%
2178
April1st to 10thNight
22%11%46%5%24446%31%
1836
11th to 20thNight
19%9%47%5%23445%36%
1673
21st to endNight
21%10%37%6%35%446%31%
1620
May1st to 10thNight
18%7%25%5%345%5%8%37%
1596
11th to 20thNight
15%7%25%5%345%6%7%41%
1415
21st to endNight
12%5%245%35%6%6%8%45%
1550
June1st to 10thNight
14%7%36%5%36%46%8%38%
1389
11th to 20thNight
14%6%2443347%10%44%
1260
21st to endNight
16%6%35%5%4445%8%40%
1260
July1st to 10thNight
11%4233345%5%9%52%
1260
11th to 20thNight
12%6%344345%5%8%45%
1345
21st to endNight
11%5%445%346%5%8%46%
1685
August1st to 10thNight
11%5%35%5%3446%8%47%
1611
11th to 20thNight
11%5%25%5%45%5%5%8%47%
1598
21st to endNight
16%7%244345%6%8%42%
1825
September1st to 10thNight
11%425%5%4446%8%47%
1800
11th to 20thNight
14%5%24425%45%8%47%
1912
21st to endNight
18%7%25%5%3445%6%40%
2008
October1st to 10thNight
22%8%36%5%35%45%6%35%
2160
11th to 20thNight
26%11%47%6%345%46%25%
2160
21st to endNight
29%11%47%6%24445%24%
2385
November1st to 10thNight
23%12%37%424346%30%
2542
11th to 20thNight
19%15%5%7%6%35%46%6%24%
2660
21st to endNight
25%18%6%8%5%35%445%18%
2660
December1st to 10thNight
20%24%8%9%5%3345%5%13%
2660
11th to 20thNight
22%22%8%11%6%2333417%
3288
21st to endNight
25%22%6%12%6%3433412%
5144

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%49%13%4
1329
11th to 20thDay
68%47%10%9%1
1507
21st to endDay
67%5%6%9%11%1
1782
February1st to 10thDay
71%47%13%41
1620
11th to 20thDay
62%6%9%13%9%1
1582
21st to endDay
66%5%7%15%6%
1361
March1st to 10thDay
56%6%12%14%11%1
1966
11th to 20thDay
55%5%9%19%11%2
1980
21st to endDay
51%5%9%17%14%3
2178
April1st to 10thDay
57%5%10%17%9%1
2124
11th to 20thDay
50%5%7%23%14%1
2251
21st to endDay
52%5%9%18%13%3
2340
May1st to 10thDay
49%6%9%21%13%3
2362
11th to 20thDay
44%7%9%24%14%2
2482
21st to endDay
40%7%15%23%13%3
2725
June1st to 10thDay
45%7%10%24%14%1
2565
11th to 20thDay
42%6%11%24%16%1
2700
21st to endDay
46%7%13%22%11%1
2700
July1st to 10thDay
34%9%13%27%15%1
2626
11th to 20thDay
37%7%14%29%12%1
2530
21st to endDay
41%8%12%27%12%1
2483
August1st to 10thDay
39%8%15%25%12%1
2314
11th to 20thDay
39%9%15%27%9%1
2303
21st to endDay
42%8%15%23%11%1
2512
September1st to 10thDay
40%8%14%27%11%1
2160
11th to 20thDay
41%6%15%28%10%1
2046
21st to endDay
50%7%11%25%7%
1951
October1st to 10thDay
52%7%12%18%10%1
1800
11th to 20thDay
62%7%12%13%6%1
1800
21st to endDay
65%6%9%13%6%1
1967
November1st to 10thDay
56%7%14%17%5%
1533
11th to 20thDay
64%5%13%12%5%1
1520
21st to endDay
69%7%9%11%31
1520
December1st to 10thDay
72%49%10%41
1520
11th to 20thDay
71%47%11%7%
1906
21st to endDay
76%46%10%3
2510
January1st to 10thNight
73%5%8%9%5%
2838
11th to 20thNight
70%5%7%10%7%1
2474
21st to endNight
63%6%6%14%10%1
2574
February1st to 10thNight
67%6%8%13%5%1
2340
11th to 20thNight
62%5%10%16%7%1
2275
21st to endNight
64%5%8%15%7%1
1893
March1st to 10thNight
53%5%13%16%12%1
1992
11th to 20thNight
52%5%10%19%11%2
1980
21st to endNight
49%49%20%15%3
2178
April1st to 10thNight
55%5%8%19%12%2
1836
11th to 20thNight
50%47%21%16%2
1673
21st to endNight
54%5%8%15%15%2
1620
May1st to 10thNight
44%5%10%21%16%3
1596
11th to 20thNight
40%5%9%23%20%2
1416
21st to endNight
36%6%16%23%17%3
1551
June1st to 10thNight
45%6%10%23%14%2
1389
11th to 20thNight
35%6%12%26%20%
1260
21st to endNight
41%7%15%24%12%1
1260
July1st to 10thNight
28%6%13%29%20%3
1225
11th to 20thNight
37%6%12%30%13%1
1303
21st to endNight
36%6%14%29%14%1
1591
August1st to 10thNight
35%6%18%27%13%1
1600
11th to 20thNight
34%8%17%26%13%1
1598
21st to endNight
40%7%14%27%11%1
1825
September1st to 10thNight
36%8%16%25%14%1
1800
11th to 20thNight
35%7%16%31%11%
1912
21st to endNight
45%5%12%29%9%
2008
October1st to 10thNight
50%6%12%19%12%
2160
11th to 20thNight
60%7%11%17%4
2160
21st to endNight
65%5%9%13%8%1
2385
November1st to 10thNight
55%5%12%21%7%1
2542
11th to 20thNight
59%5%14%14%6%1
2660
21st to endNight
68%5%12%11%3
2660
December1st to 10thNight
73%6%8%9%4
2660
11th to 20thNight
72%5%8%11%4
3288
21st to endNight
78%47%9%3
5144

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
22%23%35%14%41
180
11th to 20thDay
29%20%32%15%5%1
200
21st to endDay
30%14%34%16%5%
264
February1st to 10thDay
32%28%32%6%21
240
11th to 20thDay
24%26%39%10%1
240
21st to endDay
35%30%28%7%
198
March1st to 10thDay
23%21%38%15%4
406
11th to 20thDay
22%20%37%16%5%1
420
21st to endDay
29%16%32%16%6%1
462
April1st to 10thDay
27%19%31%15%8%
420
11th to 20thDay
32%18%23%17%8%2
412
21st to endDay
29%15%35%14%6%1
420
May1st to 10thDay
26%13%32%18%8%3
423
11th to 20thDay
21%16%29%20%10%4
447
21st to endDay
19%13%32%22%12%2
485
June1st to 10thDay
19%12%33%27%7%1
495
11th to 20thDay
17%15%32%25%10%2
630
21st to endDay
21%10%36%23%8%2
630
July1st to 10thDay
12%9%34%29%14%2
621
11th to 20thDay
16%10%27%29%14%4
529
21st to endDay
13%8%34%30%10%5%
488
August1st to 10thDay
16%427%31%14%7%
446
11th to 20thDay
18%326%27%16%10%
439
21st to endDay
17%9%29%25%14%6%
495
September1st to 10thDay
14%11%30%25%13%7%
450
11th to 20thDay
17%6%29%26%17%5%
450
21st to endDay
19%13%24%29%13%3
450
October1st to 10thDay
26%15%24%19%12%3
450
11th to 20thDay
30%18%32%14%41
450
21st to endDay
39%15%30%14%2
482
November1st to 10thDay
30%19%34%16%1
203
11th to 20thDay
24%24%37%12%2
180
21st to endDay
34%18%38%8%21
180
December1st to 10thDay
32%20%31%15%21
180
11th to 20thDay
38%24%23%12%21
180
21st to endDay
39%19%31%7%41
198
January1st to 10thNight
28%17%31%20%41
950
11th to 20thNight
31%15%31%19%41
746
21st to endNight
21%12%36%22%9%1
792
February1st to 10thNight
25%18%35%19%3
720
11th to 20thNight
21%16%35%21%6%
703
21st to endNight
25%21%29%21%5%
592
March1st to 10thNight
21%18%33%24%4
720
11th to 20thNight
20%18%34%22%5%1
720
21st to endNight
21%12%31%26%9%1
792
April1st to 10thNight
28%14%30%23%6%
720
11th to 20thNight
24%14%27%24%9%1
609
21st to endNight
24%10%29%27%9%
540
May1st to 10thNight
23%5%24%34%11%2
516
11th to 20thNight
18%9%30%32%11%1
354
21st to endNight
13%5%32%33%16%
389
June1st to 10thNight
19%6%28%34%12%
360
11th to 20thNight
17%7%26%36%14%
360
21st to endNight
20%6%23%37%15%1
360
July1st to 10thNight
11%5%21%44%18%1
350
11th to 20thNight
14%7%23%35%21%1
348
21st to endNight
12%6%24%36%21%1
505
August1st to 10thNight
15%5%17%36%26%2
537
11th to 20thNight
12%418%38%25%3
534
21st to endNight
19%5%23%31%19%3
637
September1st to 10thNight
14%6%27%31%19%3
720
11th to 20thNight
15%7%24%31%19%4
720
21st to endNight
21%7%22%30%18%3
720
October1st to 10thNight
24%11%26%25%12%1
720
11th to 20thNight
32%12%26%23%7%1
720
21st to endNight
35%14%28%19%4
792
November1st to 10thNight
34%9%26%22%8%1
740
11th to 20thNight
29%16%30%19%6%
760
21st to endNight
35%14%29%18%4
760
December1st to 10thNight
34%19%28%14%4
760
11th to 20thNight
31%19%33%14%31
760
21st to endNight
34%15%30%18%3
992
Page generated at 2024-01-09 07:14:45. Version ac07

Copyright 2024 Attilla Danko


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