Misti Mountain Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Misti Mountain Observatory clear sky chart from 2005-11-05 to 2017-10-06.

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
74%
15847
36%
47146
31%
15810
80%
15810
57%
21820

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
68%
717
34%
2327
32%
716
75%
716
48%
1101
January16th to endNight
64%
768
35%
2496
32%
768
73%
768
44%
1232
February1st to 15thNight
67%
696
36%
2133
31%
696
78%
696
53%
1009
February16th to endNight
62%
632
35%
1895
34%
632
68%
632
46%
967
March1st to 15thNight
66%
720
37%
2043
31%
720
75%
720
55%
986
March16th to endNight
72%
768
36%
2112
28%
768
78%
768
59%
1005
April1st to 15thNight
61%
719
31%
1925
18%
719
69%
719
56%
953
April16th to endNight
67%
579
44%
1659
28%
579
78%
579
70%
698
May1st to 15thNight
73%
539
38%
1619
27%
539
80%
539
70%
652
May16th to endNight
71%
561
37%
1685
28%
561
76%
561
65%
699
June1st to 15thNight
79%
540
32%
1620
28%
540
81%
540
71%
661
June16th to endNight
87%
540
35%
1620
33%
540
88%
540
79%
617
July1st to 15thNight
87%
510
26%
1530
24%
510
87%
510
54%
735
July16th to endNight
83%
564
28%
1593
24%
531
84%
531
44%
846
August1st to 15thNight
86%
539
36%
1611
30%
536
86%
536
56%
754
August16th to endNight
87%
723
39%
1872
30%
723
87%
723
57%
976
September1st to 15thNight
82%
720
31%
1980
26%
720
83%
720
54%
1012
September16th to endNight
82%
716
46%
1980
36%
716
88%
716
75%
841
October1st to 15thNight
77%
684
40%
1908
32%
684
83%
684
67%
858
October16th to endNight
78%
704
43%
2112
38%
704
84%
704
66%
896
November1st to 15thNight
77%
700
38%
2250
35%
700
84%
700
61%
951
November16th to endNight
73%
720
41%
2340
39%
720
82%
720
60%
979
December1st to 15thNight
72%
720
35%
2340
33%
720
78%
720
48%
1111
December16th to endNight
63%
768
35%
2496
33%
768
70%
768
41%
1281

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
3212323346%67%
48051
Night
3212213346%69%
47341
TransparencyDay
17%25%14%26%32%
47746
Night
16%26%15%28%30%
47147
SeeingDay
49%25%36%17%6%
5631
Night
4213%35%35%8%
15861

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
4313322326%65%
1611
16th to endDay
6%313313346%62%
1728
February1st to 15thDay
3413323338%63%
1727
16th to endDay
7%423324446%56%
1579
March1st to 15thDay
331221235%6%67%
1917
16th to endDay
3312213347%66%
2112
April1st to 15thDay
2212313346%66%
2020
16th to endDay
1111111236%75%
2301
May1st to 15thDay
12312345%73%
2331
16th to endDay
12221223475%
2429
June1st to 15thDay
1111122382%
2340
16th to endDay
11123482%
2340
July1st to 15thDay
1214424446%61%
2340
16th to endDay
4325%6%46%6%7%8%43%
2467
August1st to 15thDay
2214425%5%5%7%57%
2340
16th to endDay
2214335%45%6%59%
2327
September1st to 15thDay
22133345%5%7%59%
1980
16th to endDay
1211112235%76%
1980
October1st to 15thDay
12222334472%
1847
16th to endDay
111212236%75%
1760
November1st to 15thDay
12223335%73%
1607
16th to endDay
4212111236%72%
1620
December1st to 15thDay
45%1232435%8%58%
1620
16th to endDay
9%412113347%58%
1728
January1st to 15thNight
4213323335%66%
2327
16th to endNight
6%313223345%62%
2496
February1st to 15thNight
3313212236%68%
2122
16th to endNight
5%323323346%60%
1895
March1st to 15thNight
221222335%7%66%
2043
16th to endNight
211222335%7%67%
2112
April1st to 15thNight
2112314336%69%
1925
16th to endNight
111112235%79%
1659
May1st to 15thNight
111111326%78%
1619
16th to endNight
2211122478%
1684
June1st to 15thNight
21223380%
1620
16th to endNight
11123483%
1620
July1st to 15thNight
111232336%7%64%
1620
16th to endNight
2213335%6%7%9%51%
1701
August1st to 15thNight
211222336%6%65%
1620
16th to endNight
223323447%64%
1872
September1st to 15thNight
211342335%6%64%
1980
16th to endNight
111112383%
1980
October1st to 15thNight
21112335%76%
1908
16th to endNight
122211235%76%
2112
November1st to 15thNight
1112213335%73%
2250
16th to endNight
311123235%73%
2340
December1st to 15thNight
5%32223346%63%
2340
16th to endNight
8%412323346%59%
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
21%25%16%31%21%
1612
16th to endDay
23%26%17%30%18%
1728
February1st to 15thDay
21%26%19%26%23%
1727
16th to endDay
27%25%15%28%19%
1579
March1st to 15thDay
17%1415%35%24%
1917
16th to endDay
17%25%18%33%21%
2112
April1st to 15thDay
18%1416%29%28%
2020
16th to endDay
10%1416%30%36%
2301
May1st to 15thDay
12%25%13%31%34%
2331
16th to endDay
13%1410%29%39%
2432
June1st to 15thDay
8%126%19%61%
2340
16th to endDay
6%215%14%69%
2340
July1st to 15thDay
20%5%6%10%16%39%
2201
16th to endDay
31%6%12%18%15%15%
2312
August1st to 15thDay
23%48%14%21%27%
2325
16th to endDay
22%49%11%28%24%
2327
September1st to 15thDay
21%5%9%14%21%28%
1980
16th to endDay
11%139%27%46%
1980
October1st to 15thDay
15%2411%27%37%
1847
16th to endDay
11%15%13%28%39%
1760
November1st to 15thDay
13%2317%32%30%
1607
16th to endDay
15%2416%29%31%
1620
December1st to 15thDay
23%38%23%23%17%
1620
16th to endDay
25%39%22%24%14%
1728
January1st to 15thNight
20%3419%34%18%
2327
16th to endNight
23%35%18%25%22%
2496
February1st to 15thNight
19%27%19%25%26%
2133
16th to endNight
23%36%16%31%18%
1895
March1st to 15thNight
17%25%14%35%23%
2043
16th to endNight
15%27%18%33%22%
2112
April1st to 15thNight
16%35%13%35%24%
1925
16th to endNight
9%1314%33%37%
1659
May1st to 15thNight
8%2415%32%36%
1620
16th to endNight
11%1411%34%37%
1685
June1st to 15thNight
9%126%20%59%
1620
16th to endNight
6%126%13%70%
1620
July1st to 15thNight
17%48%12%14%41%
1530
16th to endNight
22%7%12%21%21%15%
1593
August1st to 15thNight
16%46%15%27%30%
1611
16th to endNight
19%36%17%28%24%
1872
September1st to 15thNight
19%39%16%21%29%
1980
16th to endNight
8%128%29%49%
1980
October1st to 15thNight
12%25%13%28%38%
1908
16th to endNight
11%25%11%25%43%
2112
November1st to 15thNight
13%2415%36%28%
2250
16th to endNight
14%15%16%28%33%
2340
December1st to 15thNight
21%27%20%27%20%
2340
16th to endNight
26%38%21%28%12%
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
23%10%20%34%11%1
90
16th to endDay
9%6%20%35%15%12%
96
February1st to 15thDay
7%9%33%32%14%2
242
16th to endDay
9%19%35%21%13%1
238
March1st to 15thDay
6%14%28%32%14%3
270
16th to endDay
319%31%28%13%3
288
April1st to 15thDay
8%21%29%24%12%4
269
16th to endDay
327%33%23%8%2
270
May1st to 15thDay
417%30%31%12%4
288
16th to endDay
213%33%33%13%3
330
June1st to 15thDay
26%35%36%12%5%
315
16th to endDay
1220%51%15%8%
315
July1st to 15thDay
1119%47%22%7%
305
16th to endDay
6%18%44%27%11%
327
August1st to 15thDay
5%115%44%24%9%
315
16th to endDay
313%43%26%12%
332
September1st to 15thDay
3326%39%18%9%
315
16th to endDay
29%22%38%20%6%
315
October1st to 15thDay
411%31%31%17%4
249
16th to endDay
5%418%34%30%7%
96
November1st to 15thDay
3317%26%32%16%
90
16th to endDay
13%6%31%25%23%
90
December1st to 15thDay
15%20%40%31%2
90
16th to endDay
15%5%21%40%15%1
96
January1st to 15thNight
5%318%40%23%9%
720
16th to endNight
8%317%38%25%5%
768
February1st to 15thNight
6%216%41%26%5%
704
16th to endNight
6%421%41%20%4
632
March1st to 15thNight
4420%37%27%5%
720
16th to endNight
25%15%42%28%5%
768
April1st to 15thNight
36%23%36%25%4
719
16th to endNight
15%22%38%25%5%
579
May1st to 15thNight
2318%39%31%4
540
16th to endNight
1417%40%29%6%
563
June1st to 15thNight
115%41%36%4
540
16th to endNight
7%33%50%6%
540
July1st to 15thNight
3225%57%11%
510
16th to endNight
4116%63%13%
564
August1st to 15thNight
3221%60%11%
539
16th to endNight
3217%55%19%
723
September1st to 15thNight
2427%51%13%
720
16th to endNight
2111%31%39%13%
716
October1st to 15thNight
2213%41%32%6%
684
16th to endNight
2212%34%35%12%
704
November1st to 15thNight
2113%41%32%8%
700
16th to endNight
3316%33%31%10%
720
December1st to 15thNight
7%213%43%26%6%
720
16th to endNight
11%316%38%23%6%
768
Page generated at 2017-10-07 11:07:54. Version ac04

Copyright 2017 A. Danko


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