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Hole-in-the-Wall Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hole-in-the-Wall Campground clear sky chart from 2005-11-05 to 2017-09-10.

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
65%
15938
38%
46878
27%
15899
75%
15899
56%
21236

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 15thNight
52%
719
34%
2327
23%
716
68%
716
45%
1085
January16th to endNight
49%
768
37%
2430
23%
768
67%
768
41%
1181
February1st to 15thNight
52%
696
37%
2112
25%
696
68%
696
52%
972
February16th to endNight
52%
632
36%
1895
31%
632
64%
632
46%
938
March1st to 15thNight
55%
720
35%
2109
26%
720
69%
720
47%
1008
March16th to endNight
55%
768
37%
2112
24%
768
68%
768
53%
1024
April1st to 15thNight
46%
719
37%
1814
15%
719
60%
719
54%
886
April16th to endNight
55%
654
42%
1734
18%
654
69%
654
62%
776
May1st to 15thNight
62%
539
39%
1619
23%
539
72%
539
64%
660
May16th to endNight
59%
561
38%
1685
23%
561
70%
561
66%
667
June1st to 15thNight
70%
540
33%
1620
26%
540
75%
540
68%
656
June16th to endNight
80%
540
37%
1620
29%
540
85%
540
77%
625
July1st to 15thNight
86%
510
31%
1530
26%
510
88%
510
63%
670
July16th to endNight
84%
564
32%
1593
27%
531
86%
531
50%
794
August1st to 15thNight
87%
616
39%
1689
27%
613
89%
613
68%
763
August16th to endNight
88%
764
42%
1910
30%
764
89%
764
70%
931
September1st to 15thNight
84%
700
37%
1862
29%
700
86%
700
66%
882
September16th to endNight
79%
656
47%
1815
37%
656
87%
656
78%
751
October1st to 15thNight
69%
660
45%
1815
33%
660
79%
660
65%
825
October16th to endNight
71%
704
44%
2136
36%
704
83%
704
63%
886
November1st to 15thNight
66%
700
39%
2275
32%
700
80%
700
59%
939
November16th to endNight
66%
720
42%
2340
36%
720
78%
720
55%
985
December1st to 15thNight
57%
720
36%
2340
27%
720
71%
720
45%
1118
December16th to endNight
51%
768
37%
2496
26%
768
67%
768
39%
1214

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
2212213335%70%
47749
Night
2212213345%70%
47073
TransparencyDay
14%2314%27%38%
47444
Night
14%2314%28%36%
46879
SeeingDay
410%24%36%19%4
5679
Night
47%17%30%31%8%
15950

By Month

Percentage Cloud Cover SW (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 15thDay
3313213237%67%
1611
16th to endDay
5%313324335%62%
1791
February1st to 15thDay
4212313446%64%
1751
16th to endDay
5%5%13422436%58%
1579
March1st to 15thDay
2212213347%67%
1851
16th to endDay
2212224447%65%
2112
April1st to 15thDay
3213313346%66%
2131
16th to endDay
121222335%75%
2226
May1st to 15thDay
11212335%76%
2331
16th to endDay
122222325%74%
2429
June1st to 15thDay
11111132481%
2340
16th to endDay
11212285%
2340
July1st to 15thDay
321322345%5%65%
2340
16th to endDay
3314324447%59%
2467
August1st to 15thDay
1212223335%71%
2259
16th to endDay
3212323345%68%
2292
September1st to 15thDay
1111223346%71%
1984
16th to endDay
1111222482%
1815
October1st to 15thDay
2112311225%74%
1815
16th to endDay
111212235%77%
1733
November1st to 15thDay
2212212335%71%
1584
16th to endDay
2212113347%68%
1620
December1st to 15thDay
34244135%6%7%56%
1620
16th to endDay
6%324224336%58%
1728
January1st to 15thNight
2213324445%64%
2327
16th to endNight
5%313424345%62%
2430
February1st to 15thNight
2313312346%66%
2101
16th to endNight
5%413313445%62%
1895
March1st to 15thNight
23133145%5%6%62%
2109
16th to endNight
121332436%7%64%
2112
April1st to 15thNight
2212312346%70%
1814
16th to endNight
11112246%76%
1734
May1st to 15thNight
11112236%77%
1619
16th to endNight
111112235%78%
1684
June1st to 15thNight
1221221480%
1620
16th to endNight
11122286%
1620
July1st to 15thNight
1112214345%71%
1620
16th to endNight
5%21322445%9%58%
1701
August1st to 15thNight
111212337%73%
1698
16th to endNight
112212245%73%
1910
September1st to 15thNight
1212213245%71%
1862
16th to endNight
111111385%
1815
October1st to 15thNight
211112335%75%
1815
16th to endNight
1221223477%
2136
November1st to 15thNight
121221223474%
2275
16th to endNight
3312213425%71%
2340
December1st to 15thNight
43134235%5%6%60%
2340
16th to endNight
6%323223346%60%
2496

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 15thDay
17%2420%32%22%
1612
16th to endDay
22%25%18%30%20%
1791
February1st to 15thDay
18%25%17%30%25%
1751
16th to endDay
25%1416%31%20%
1579
March1st to 15thDay
13%2318%32%29%
1851
16th to endDay
15%2421%34%22%
2112
April1st to 15thDay
17%1216%32%28%
2131
16th to endDay
11%1115%32%37%
2226
May1st to 15thDay
9%1214%32%39%
2331
16th to endDay
11%219%31%43%
2432
June1st to 15thDay
7%17%17%64%
2340
16th to endDay
7%1310%76%
2340
July1st to 15thDay
17%329%17%49%
2201
16th to endDay
19%35%16%22%31%
2312
August1st to 15thDay
13%3110%25%44%
2244
16th to endDay
16%2110%26%41%
2292
September1st to 15thDay
12%2412%21%45%
1984
16th to endDay
8%16%27%55%
1815
October1st to 15thDay
14%129%29%41%
1815
16th to endDay
11%2212%28%42%
1733
November1st to 15thDay
14%1215%31%33%
1584
16th to endDay
14%2416%31%30%
1620
December1st to 15thDay
21%37%20%25%21%
1620
16th to endDay
24%37%22%26%15%
1728
January1st to 15thNight
19%3417%29%25%
2327
16th to endNight
22%2418%25%26%
2430
February1st to 15thNight
17%25%19%28%27%
2112
16th to endNight
21%25%18%33%19%
1895
March1st to 15thNight
17%2316%33%25%
2109
16th to endNight
15%35%20%33%22%
2112
April1st to 15thNight
14%1416%36%26%
1814
16th to endNight
9%1116%31%39%
1734
May1st to 15thNight
9%2214%34%37%
1620
16th to endNight
8%1212%35%38%
1685
June1st to 15thNight
9%18%17%62%
1620
16th to endNight
7%5%11%74%
1620
July1st to 15thNight
12%3210%17%53%
1530
16th to endNight
20%4413%25%32%
1593
August1st to 15thNight
10%3213%24%46%
1689
16th to endNight
11%2211%25%46%
1910
September1st to 15thNight
13%2412%25%41%
1862
16th to endNight
6%18%23%59%
1815
October1st to 15thNight
11%2210%31%41%
1815
16th to endNight
10%2310%24%49%
2136
November1st to 15thNight
13%1213%35%34%
2275
16th to endNight
13%2217%26%37%
2340
December1st to 15thNight
21%35%17%29%23%
2340
16th to endNight
23%26%19%29%17%
2496

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 15thDay
17%15%31%30%41
90
16th to endDay
11%15%28%28%11%3
159
February1st to 15thDay
6%11%41%27%10%2
266
16th to endDay
10%17%34%25%11%
238
March1st to 15thDay
5%16%29%30%16%1
270
16th to endDay
5%20%29%29%12%1
288
April1st to 15thDay
9%19%33%20%13%3
269
16th to endDay
426%32%24%11%1
270
May1st to 15thDay
312%31%33%14%4
288
16th to endDay
210%33%37%13%3
330
June1st to 15thDay
26%33%38%15%3
315
16th to endDay
317%48%23%5%
315
July1st to 15thDay
115%46%27%7%
305
16th to endDay
317%50%29%7%
327
August1st to 15thDay
2213%51%23%7%
315
16th to endDay
310%44%29%10%
332
September1st to 15thDay
3220%44%25%4
294
16th to endDay
38%19%40%23%3
255
October1st to 15thDay
5%9%30%37%14%2
255
16th to endDay
410%18%32%31%2
132
November1st to 15thDay
214%21%26%26%8%
90
16th to endDay
6%15%33%28%13%2
90
December1st to 15thDay
5%13%20%35%24%1
90
16th to endDay
13%15%19%32%17%1
96
January1st to 15thNight
5%9%25%30%21%7%
720
16th to endNight
8%10%24%30%19%5%
768
February1st to 15thNight
46%27%32%23%5%
704
16th to endNight
8%8%24%34%17%6%
632
March1st to 15thNight
413%20%32%24%5%
720
16th to endNight
312%22%31%23%7%
768
April1st to 15thNight
416%27%26%19%6%
719
16th to endNight
214%24%31%21%6%
654
May1st to 15thNight
28%23%33%27%4
540
16th to endNight
112%23%29%27%5%
563
June1st to 15thNight
15%18%38%32%3
540
16th to endNight
1215%34%42%3
540
July1st to 15thNight
2428%55%8%
510
16th to endNight
5%1121%60%8%
564
August1st to 15thNight
1424%58%9%
616
16th to endNight
2219%52%21%
764
September1st to 15thNight
2425%48%18%
700
16th to endNight
2312%25%36%19%
656
October1st to 15thNight
3417%37%28%8%
660
16th to endNight
17%13%29%33%13%
704
November1st to 15thNight
16%19%34%28%9%
700
16th to endNight
48%14%32%28%11%
720
December1st to 15thNight
7%6%20%32%26%6%
720
16th to endNight
10%10%19%31%20%6%
768
Page generated at 2017-09-11 16:35:15. Version ac04

Copyright 2017 A. Danko


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