Curiosity Peak Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Curiosity Peak Observatory clear sky chart from 2005-11-05 to 2018-01-20.

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
69%
16696
35%
48526
28%
16655
74%
16655
49%
24728

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
58%
776
29%
2522
27%
776
65%
776
36%
1347
January16th to endNight
54%
788
34%
2380
26%
788
65%
788
34%
1358
February1st to 15thNight
59%
699
32%
2112
27%
699
67%
699
38%
1161
February16th to endNight
51%
632
29%
1895
28%
632
57%
632
30%
1159
March1st to 15thNight
55%
720
30%
2145
27%
720
63%
720
38%
1186
March16th to endNight
62%
768
31%
2064
25%
768
67%
768
43%
1176
April1st to 15thNight
54%
719
31%
1799
17%
719
61%
719
43%
1062
April16th to endNight
59%
720
33%
1800
17%
720
66%
720
52%
994
May1st to 15thNight
65%
562
34%
1642
23%
562
70%
562
50%
829
May16th to endNight
66%
562
34%
1685
24%
561
70%
561
50%
824
June1st to 15thNight
76%
540
35%
1620
30%
540
78%
540
68%
687
June16th to endNight
84%
540
39%
1620
32%
540
86%
540
81%
611
July1st to 15thNight
90%
510
31%
1530
27%
510
90%
510
69%
643
July16th to endNight
85%
603
34%
1629
26%
567
85%
567
58%
767
August1st to 15thNight
91%
717
37%
1790
24%
713
91%
713
77%
825
August16th to endNight
91%
764
43%
1910
30%
764
92%
764
74%
904
September1st to 15thNight
90%
720
38%
1887
31%
720
91%
720
69%
882
September16th to endNight
84%
716
47%
1980
41%
716
88%
716
74%
850
October1st to 15thNight
72%
720
37%
1980
32%
720
77%
720
55%
988
October16th to endNight
75%
768
42%
2292
39%
768
80%
768
54%
1090
November1st to 15thNight
68%
760
32%
2470
31%
760
75%
760
46%
1207
November16th to endNight
67%
780
36%
2535
36%
780
73%
780
43%
1274
December1st to 15thNight
60%
780
32%
2535
29%
780
66%
780
35%
1374
December16th to endNight
55%
832
32%
2704
28%
832
64%
832
32%
1530

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
2313323346%67%
48995
Night
2313323346%66%
48725
TransparencyDay
20%3412%26%32%
48694
Night
20%4411%24%34%
48527
SeeingDay
7%13%32%30%11%4
6299
Night
5%6%14%31%32%9%
16707

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
4414433346%58%
1746
16th to endDay
5%5%25%5%2345%6%53%
1944
February1st to 15thDay
3314424446%57%
1751
16th to endDay
36%38%5%24448%47%
1579
March1st to 15thDay
332231335%8%60%
1814
16th to endDay
2423324347%60%
2157
April1st to 15thDay
3424324446%60%
2149
16th to endDay
2212312247%70%
2160
May1st to 15thDay
1212323326%71%
2307
16th to endDay
111212236%76%
2429
June1st to 15thDay
21111123480%
2340
16th to endDay
11111287%
2340
July1st to 15thDay
2212213346%69%
2340
16th to endDay
121342445%7%62%
2425
August1st to 15thDay
11211324476%
2160
16th to endDay
211213345%72%
2292
September1st to 15thDay
211221233473%
2072
16th to endDay
11121112382%
1980
October1st to 15thDay
1313312335%70%
1980
16th to endDay
121232323473%
1929
November1st to 15thDay
2313423336%65%
1719
16th to endDay
331342335%6%62%
1755
December1st to 15thDay
5%5%1443345%7%54%
1755
16th to endDay
45%26%5%24446%53%
1872
January1st to 15thNight
3416%5%2435%7%56%
2522
16th to endNight
44246%23347%54%
2380
February1st to 15thNight
2425%5%2345%7%56%
2101
16th to endNight
36%25%7%4445%6%49%
1895
March1st to 15thNight
34145%23447%57%
2145
16th to endNight
141442446%9%56%
2064
April1st to 15thNight
15%1431345%8%59%
1799
16th to endNight
222312338%68%
1800
May1st to 15thNight
1131336%9%67%
1642
16th to endNight
111211349%72%
1684
June1st to 15thNight
111136%81%
1620
16th to endNight
111288%
1620
July1st to 15thNight
11122345%75%
1620
16th to endNight
1213312337%69%
1740
August1st to 15thNight
122246%78%
1800
16th to endNight
111111123480%
1910
September1st to 15thNight
122223478%
1887
16th to endNight
111123384%
1980
October1st to 15thNight
113213336%70%
1980
16th to endNight
111323446%70%
2292
November1st to 15thNight
3135%23345%65%
2470
16th to endNight
2313424346%63%
2535
December1st to 15thNight
4415%42436%7%54%
2535
16th to endNight
45%25%6%34335%55%
2704

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
28%2413%26%22%
1747
16th to endDay
31%45%12%20%26%
1944
February1st to 15thDay
28%3412%24%26%
1751
16th to endDay
38%45%13%23%14%
1579
March1st to 15thDay
23%45%13%27%25%
1814
16th to endDay
25%45%17%28%17%
2157
April1st to 15thDay
26%5%318%30%14%
2149
16th to endDay
16%45%20%30%23%
2160
May1st to 15thDay
17%4314%30%28%
2307
16th to endDay
12%4416%38%23%
2432
June1st to 15thDay
11%3210%25%46%
2340
16th to endDay
7%11414%71%
2340
July1st to 15thDay
14%349%22%45%
2201
16th to endDay
19%5%7%18%24%23%
2273
August1st to 15thDay
11%2412%27%41%
2146
16th to endDay
15%239%30%38%
2292
September1st to 15thDay
15%349%27%40%
2072
16th to endDay
10%216%30%47%
1980
October1st to 15thDay
19%2411%26%35%
1980
16th to endDay
17%338%21%46%
1929
November1st to 15thDay
22%3412%24%32%
1719
16th to endDay
23%3311%25%32%
1755
December1st to 15thDay
29%46%13%18%28%
1755
16th to endDay
32%45%14%24%18%
1872
January1st to 15thNight
28%4414%22%26%
2522
16th to endNight
31%4411%18%28%
2380
February1st to 15thNight
28%4311%23%27%
2112
16th to endNight
37%4312%21%20%
1895
March1st to 15thNight
26%6%414%22%25%
2145
16th to endNight
25%6%5%14%26%21%
2064
April1st to 15thNight
25%6%415%31%16%
1799
16th to endNight
17%7%416%26%28%
1800
May1st to 15thNight
15%8%411%27%31%
1643
16th to endNight
12%10%412%31%28%
1685
June1st to 15thNight
8%428%23%51%
1620
16th to endNight
5%1412%74%
1620
July1st to 15thNight
10%247%22%52%
1530
16th to endNight
16%37%17%27%27%
1629
August1st to 15thNight
9%1313%27%45%
1790
16th to endNight
9%238%27%48%
1910
September1st to 15thNight
10%3310%26%45%
1887
16th to endNight
7%315%30%50%
1980
October1st to 15thNight
17%3410%26%37%
1980
16th to endNight
16%429%19%47%
2292
November1st to 15thNight
21%4310%26%33%
2470
16th to endNight
22%5%311%23%33%
2535
December1st to 15thNight
28%5%413%20%26%
2535
16th to endNight
33%35%13%22%21%
2704

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
25%13%16%34%9%1
135
16th to endDay
16%18%31%24%7%1
287
February1st to 15thDay
11%14%40%23%8%
266
16th to endDay
15%25%31%18%7%
238
March1st to 15thDay
12%22%31%20%10%2
270
16th to endDay
12%20%36%19%10%1
288
April1st to 15thDay
13%27%34%15%7%2
269
16th to endDay
10%25%38%16%7%1
270
May1st to 15thDay
9%21%39%21%6%2
288
16th to endDay
319%42%22%8%3
330
June1st to 15thDay
213%39%28%12%3
315
16th to endDay
3435%32%15%7%
315
July1st to 15thDay
2225%47%14%6%
305
16th to endDay
219%50%15%10%
327
August1st to 15thDay
1229%42%13%10%
315
16th to endDay
223%49%14%9%
332
September1st to 15thDay
3439%38%9%4
315
16th to endDay
5%13%32%35%10%2
315
October1st to 15thDay
5%13%43%27%9%
315
16th to endDay
5%11%30%31%17%3
255
November1st to 15thDay
10%11%23%32%19%2
135
16th to endDay
11%15%21%31%14%4
135
December1st to 15thDay
6%11%22%40%20%
135
16th to endDay
15%13%22%26%15%5%
144
January1st to 15thNight
7%9%16%32%25%8%
780
16th to endNight
12%9%15%32%23%5%
788
February1st to 15thNight
8%9%18%31%25%6%
704
16th to endNight
10%13%18%32%19%5%
632
March1st to 15thNight
8%10%20%34%20%5%
720
16th to endNight
7%7%19%33%25%7%
768
April1st to 15thNight
8%10%23%32%19%5%
719
16th to endNight
5%9%23%30%22%7%
720
May1st to 15thNight
37%22%37%24%4
563
16th to endNight
29%19%36%26%5%
563
June1st to 15thNight
1217%47%26%3
540
16th to endNight
111%41%40%4
540
July1st to 15thNight
2233%53%7%
510
16th to endNight
11325%56%10%
603
August1st to 15thNight
225%55%15%
717
16th to endNight
2216%55%22%
764
September1st to 15thNight
1426%51%15%
720
16th to endNight
129%34%38%14%
716
October1st to 15thNight
37%15%33%32%8%
720
16th to endNight
3313%29%33%16%
768
November1st to 15thNight
45%17%36%28%9%
760
16th to endNight
6%5%15%28%30%12%
780
December1st to 15thNight
9%9%15%31%26%7%
780
16th to endNight
12%10%16%29%24%7%
832
Page generated at 2018-01-21 09:19:29. Version ac04

Copyright 2018 A. Danko


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