This page made possible by the sponsorship of: Bob Taylor.

Mount Pinos
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mount Pinos clear sky chart from 2005-11-05 to 2017-05-24.

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
68%
15367
33%
45835
28%
15326
73%
15326
51%
22392

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
54%
716
25%
2443
22%
716
61%
716
36%
1286
January16th to endNight
52%
768
30%
2466
25%
768
61%
768
33%
1364
February1st to 15thNight
55%
700
29%
2110
27%
699
61%
699
39%
1153
February16th to endNight
52%
632
27%
1895
26%
632
57%
632
34%
1101
March1st to 15thNight
55%
720
23%
2144
21%
720
60%
720
37%
1190
March16th to endNight
58%
768
27%
1998
20%
768
63%
768
46%
1128
April1st to 15thNight
49%
719
27%
1799
13%
719
55%
719
45%
1041
April16th to endNight
59%
720
32%
1800
15%
720
65%
720
60%
907
May1st to 15thNight
66%
656
31%
1736
18%
656
69%
656
61%
850
May16th to endNight
60%
526
31%
1608
20%
526
68%
526
58%
689
June1st to 15thNight
79%
330
36%
1320
40%
330
85%
330
60%
461
June16th to endNight
93%
330
40%
1320
48%
330
95%
330
81%
386
July1st to 15thNight
92%
310
37%
1240
44%
310
93%
310
67%
412
July16th to endNight
92%
527
37%
1469
32%
491
92%
491
71%
608
August1st to 15thNight
93%
657
41%
1640
27%
653
93%
653
83%
719
August16th to endNight
94%
700
43%
1750
28%
700
94%
700
80%
792
September1st to 15thNight
92%
660
46%
1650
36%
660
93%
660
79%
759
September16th to endNight
87%
656
45%
1808
41%
656
91%
656
78%
756
October1st to 15thNight
73%
660
35%
1889
34%
660
79%
660
58%
888
October16th to endNight
71%
704
39%
2112
38%
704
79%
704
59%
958
November1st to 15thNight
69%
700
33%
2267
34%
700
73%
700
50%
1047
November16th to endNight
66%
720
32%
2340
31%
720
72%
720
46%
1138
December1st to 15thNight
58%
720
30%
2343
27%
720
65%
720
35%
1273
December16th to endNight
51%
768
27%
2688
27%
768
58%
768
29%
1486

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
3313323346%64%
46433
Night
2423323346%62%
46025
TransparencyDay
19%36%17%28%25%
46121
Night
19%37%18%28%22%
45838
SeeingDay
7%12%30%35%10%3
5499
Night
5%5%16%32%31%8%
15378

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
44245%35%447%52%
1493
16th to endDay
5%8%37%6%24235%49%
1755
February1st to 15thDay
47%34425%447%49%
1751
16th to endDay
6%7%35%5%23446%49%
1579
March1st to 15thDay
36%245%35%6%5%8%47%
1813
16th to endDay
36%234345%5%8%51%
2226
April1st to 15thDay
5%7%24413347%53%
2149
16th to endDay
321331345%8%62%
2160
May1st to 15thDay
321222345%7%65%
2214
16th to endDay
3412213336%67%
2346
June1st to 15thDay
113212336%70%
2310
16th to endDay
11113483%
2310
July1st to 15thDay
111222236%73%
2310
16th to endDay
2112112335%73%
2276
August1st to 15thDay
11111235%81%
1980
16th to endDay
11112245%79%
2100
September1st to 15thDay
11211235%79%
1980
16th to endDay
121223479%
1821
October1st to 15thDay
2412324445%65%
1738
16th to endDay
1213323335%68%
1760
November1st to 15thDay
25%13313347%64%
1592
16th to endDay
35%24434346%57%
1620
December1st to 15thDay
36%245%346%6%6%50%
1614
16th to endDay
7%7%34424445%49%
1536
January1st to 15thNight
35%36%6%3445%7%49%
2443
16th to endNight
47%345%345%5%5%48%
2466
February1st to 15thNight
38%35%5%2435%7%50%
2101
16th to endNight
5%6%25%6%35%45%6%47%
1895
March1st to 15thNight
26%37%5%26%5%5%7%46%
2144
16th to endNight
37%23426%5%48%50%
1998
April1st to 15thNight
38%346%25%446%51%
1799
16th to endNight
2313313348%63%
1800
May1st to 15thNight
3212213346%67%
1736
16th to endNight
321321232471%
1607
June1st to 15thNight
1212212345%73%
1320
16th to endNight
112388%
1320
July1st to 15thNight
11111223478%
1320
16th to endNight
11111223379%
1579
August1st to 15thNight
112385%
1650
16th to endNight
11112285%
1750
September1st to 15thNight
1111122384%
1650
16th to endNight
1112225%81%
1808
October1st to 15thNight
2213324445%66%
1889
16th to endNight
2214313446%66%
2112
November1st to 15thNight
342432345%5%60%
2267
16th to endNight
25%1442346%9%55%
2340
December1st to 15thNight
35%25%6%35%5%5%8%49%
2343
16th to endNight
5%9%35%5%345%5%7%44%
2688

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%37%18%25%17%
1493
16th to endDay
34%18%16%21%17%
1755
February1st to 15thDay
29%36%21%23%15%
1751
16th to endDay
32%47%22%25%7%
1579
March1st to 15thDay
26%5%12%22%19%12%
1813
16th to endDay
26%410%26%21%10%
2226
April1st to 15thDay
25%49%26%24%8%
2149
16th to endDay
17%410%26%29%11%
2160
May1st to 15thDay
16%37%22%35%14%
2214
16th to endDay
17%27%26%34%12%
2349
June1st to 15thDay
13%26%15%31%30%
2310
16th to endDay
6%127%31%50%
2310
July1st to 15thDay
12%137%22%51%
2161
16th to endDay
12%35%14%32%31%
2124
August1st to 15thDay
7%129%28%50%
1966
16th to endDay
9%228%36%39%
2100
September1st to 15thDay
8%239%31%45%
1980
16th to endDay
9%1210%38%36%
1821
October1st to 15thDay
19%2418%31%24%
1738
16th to endDay
15%35%14%32%28%
1760
November1st to 15thDay
19%25%20%31%20%
1592
16th to endDay
24%37%16%25%22%
1620
December1st to 15thDay
27%5%8%20%23%14%
1614
16th to endDay
33%38%22%17%14%
1536
January1st to 15thNight
28%47%18%24%17%
2443
16th to endNight
31%37%15%20%21%
2466
February1st to 15thNight
27%47%18%24%16%
2112
16th to endNight
32%47%22%25%8%
1895
March1st to 15thNight
27%5%9%22%19%14%
2144
16th to endNight
24%413%23%25%9%
1998
April1st to 15thNight
26%212%25%24%8%
1799
16th to endNight
13%311%29%32%9%
1800
May1st to 15thNight
14%210%26%35%10%
1737
16th to endNight
13%19%26%37%10%
1608
June1st to 15thNight
11%18%18%33%26%
1320
16th to endNight
4210%31%49%
1320
July1st to 15thNight
9%1310%24%50%
1240
16th to endNight
9%25%18%28%35%
1469
August1st to 15thNight
5%1110%33%47%
1640
16th to endNight
6%119%42%37%
1750
September1st to 15thNight
7%2211%30%45%
1650
16th to endNight
6%2115%40%33%
1808
October1st to 15thNight
16%2420%30%25%
1889
16th to endNight
14%26%14%33%27%
2112
November1st to 15thNight
19%26%18%31%20%
2267
16th to endNight
22%28%15%27%22%
2340
December1st to 15thNight
29%47%16%25%16%
2343
16th to endNight
32%48%22%18%13%
2688

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
14%21%42%15%4
121
16th to endDay
15%22%33%20%5%1
261
February1st to 15thDay
10%19%33%30%41
266
16th to endDay
13%21%35%24%5%
238
March1st to 15thDay
10%18%33%26%10%
270
16th to endDay
9%20%32%26%9%1
288
April1st to 15thDay
15%20%33%20%9%1
269
16th to endDay
5%24%37%25%5%1
270
May1st to 15thDay
13%12%34%27%9%3
288
16th to endDay
10%10%33%33%8%3
301
June1st to 15thDay
5%9%34%38%9%2
255
16th to endDay
1334%42%10%7%
255
July1st to 15thDay
2123%48%17%6%
245
16th to endDay
3117%50%17%8%
271
August1st to 15thDay
1325%50%12%7%
255
16th to endDay
1117%58%15%5%
268
September1st to 15thDay
2223%52%13%4
255
16th to endDay
2431%47%12%1
255
October1st to 15thDay
5%12%37%34%9%1
255
16th to endDay
5%12%33%40%9%
272
November1st to 15thDay
6%8%18%30%29%7%
98
16th to endDay
415%36%31%12%
90
December1st to 15thDay
10%8%23%41%15%
89
16th to endDay
15%21%25%28%9%
64
January1st to 15thNight
7%5%26%33%19%9%
720
16th to endNight
10%10%21%34%18%5%
768
February1st to 15thNight
5%7%22%34%20%8%
704
16th to endNight
9%9%21%32%19%6%
632
March1st to 15thNight
6%10%21%34%22%5%
720
16th to endNight
5%9%20%35%25%4
768
April1st to 15thNight
8%9%26%32%19%3
719
16th to endNight
48%23%33%25%4
720
May1st to 15thNight
5%421%35%29%4
657
16th to endNight
6%7%21%29%31%4
528
June1st to 15thNight
2310%43%36%3
330
16th to endNight
451%40%2
330
July1st to 15thNight
1124%62%9%
310
16th to endNight
119%60%17%
527
August1st to 15thNight
1328%56%11%
657
16th to endNight
1120%59%16%
700
September1st to 15thNight
325%55%14%
660
16th to endNight
118%33%42%13%
656
October1st to 15thNight
3215%38%31%8%
660
16th to endNight
4217%29%34%11%
704
November1st to 15thNight
4416%35%29%10%
700
16th to endNight
5%419%36%25%9%
720
December1st to 15thNight
6%6%20%37%23%5%
720
16th to endNight
10%11%20%34%16%6%
768
Page generated at 2017-05-25 10:27:30. Version ac04

Copyright 2017 A. Danko


Mount Pinos Clear Sky Chart | Charts Home