Dinosaur Point
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Dinosaur Point clear sky chart from 2005-11-05 to 2017-09-18.

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
72%
15441
29%
46914
26%
15404
75%
15404
44%
24442

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
65%
716
19%
2410
20%
716
67%
716
31%
1391
January16th to endNight
67%
768
24%
2496
26%
768
69%
768
29%
1510
February1st to 15thNight
64%
698
25%
2247
27%
698
67%
698
29%
1332
February16th to endNight
61%
632
23%
1895
21%
632
66%
632
32%
1136
March1st to 15thNight
61%
720
19%
2046
18%
720
64%
720
31%
1287
March16th to endNight
59%
768
21%
2061
16%
768
63%
768
34%
1285
April1st to 15thNight
57%
719
24%
1799
14%
719
61%
719
36%
1126
April16th to endNight
61%
720
26%
1800
11%
720
66%
720
50%
997
May1st to 15thNight
68%
668
28%
1748
16%
668
73%
668
56%
903
May16th to endNight
69%
375
29%
1496
28%
374
77%
374
48%
606
June1st to 15thNight
72%
360
30%
1440
31%
360
82%
360
49%
584
June16th to endNight
85%
360
38%
1440
46%
360
91%
360
72%
453
July1st to 15thNight
92%
346
34%
1366
41%
346
95%
346
75%
425
July16th to endNight
93%
564
37%
1593
33%
531
94%
531
71%
651
August1st to 15thNight
90%
604
37%
1677
27%
601
91%
601
74%
713
August16th to endNight
92%
764
44%
1910
29%
764
92%
764
82%
853
September1st to 15thNight
89%
720
42%
1800
29%
720
91%
720
75%
852
September16th to endNight
83%
667
44%
1805
39%
667
86%
667
68%
822
October1st to 15thNight
78%
660
30%
1980
31%
660
82%
660
49%
986
October16th to endNight
79%
704
37%
2112
40%
704
82%
704
52%
1026
November1st to 15thNight
76%
700
31%
2217
33%
700
80%
700
46%
1096
November16th to endNight
70%
720
26%
2368
26%
720
74%
720
37%
1267
December1st to 15thNight
61%
720
21%
2520
21%
720
65%
720
26%
1518
December16th to endNight
57%
768
21%
2688
20%
768
62%
768
26%
1623

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
4212213346%66%
47881
Night
5%212213348%63%
47100
TransparencyDay
20%5%9%18%24%20%
47565
Night
21%6%10%18%23%19%
46915
SeeingDay
5%8%22%32%22%7%
5977
Night
5%313%35%31%8%
15452

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
9%5%35%6%245%48%44%
1525
16th to endDay
13%5%245%245%6%7%43%
1728
February1st to 15thDay
12%5%24315%45%6%47%
1616
16th to endDay
13%316%5%246%5%7%43%
1579
March1st to 15thDay
7%325%4345%7%9%44%
1911
16th to endDay
7%326%5%345%6%6%48%
2163
April1st to 15thDay
7%4345%2345%7%51%
2149
16th to endDay
5%112223436%65%
2160
May1st to 15thDay
112212349%70%
2197
16th to endDay
2111213347%69%
2615
June1st to 15thDay
11212338%73%
2520
16th to endDay
112485%
2520
July1st to 15thDay
1125%85%
2511
16th to endDay
11122484%
2468
August1st to 15thDay
111125%85%
2274
16th to endDay
122485%
2292
September1st to 15thDay
1112486%
2160
16th to endDay
11111236%79%
1875
October1st to 15thDay
311121335%6%70%
1650
16th to endDay
323223346%66%
1760
November1st to 15thDay
6%31332445%6%58%
1642
16th to endDay
6%43333445%8%51%
1590
December1st to 15thDay
12%5%25%5%3445%6%42%
1440
16th to endDay
11%5%345%2345%7%43%
1536
January1st to 15thNight
9%42442445%7%49%
2410
16th to endNight
12%31332445%7%50%
2496
February1st to 15thNight
11%324334447%49%
2236
16th to endNight
10%21242445%9%51%
1895
March1st to 15thNight
8%3135%345%5%7%50%
2046
16th to endNight
6%422325%449%52%
2061
April1st to 15thNight
6%213325%5%7%7%54%
1799
16th to endNight
312312348%68%
1800
May1st to 15thNight
1123122410%68%
1748
16th to endNight
21111235%10%70%
1496
June1st to 15thNight
111212249%72%
1440
16th to endNight
236%84%
1440
July1st to 15thNight
2128%81%
1446
16th to endNight
112248%76%
1701
August1st to 15thNight
11111311%76%
1686
16th to endNight
1138%82%
1910
September1st to 15thNight
111126%82%
1800
16th to endNight
1122327%77%
1805
October1st to 15thNight
412113348%67%
1980
16th to endNight
321212446%69%
2112
November1st to 15thNight
5%212213348%65%
2217
16th to endNight
5%31342345%8%57%
2368
December1st to 15thNight
9%425%5%2445%6%47%
2520
16th to endNight
13%423324346%50%
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
34%8%13%19%15%7%
1525
16th to endDay
40%6%11%13%20%7%
1728
February1st to 15thDay
37%6%11%21%18%5%
1616
16th to endDay
40%9%10%22%14%2
1579
March1st to 15thDay
35%10%12%18%18%4
1911
16th to endDay
36%8%14%19%17%3
2163
April1st to 15thDay
34%7%12%21%19%4
2149
16th to endDay
22%7%12%24%25%8%
2160
May1st to 15thDay
13%6%9%27%33%9%
2197
16th to endDay
15%7%12%25%29%9%
2619
June1st to 15thDay
12%7%10%22%23%23%
2520
16th to endDay
5%2315%31%41%
2520
July1st to 15thDay
4246%21%60%
2362
16th to endDay
7%249%22%54%
2313
August1st to 15thDay
6%1312%27%48%
2258
16th to endDay
42212%34%43%
2292
September1st to 15thDay
5%3313%32%41%
2160
16th to endDay
8%35%23%37%22%
1875
October1st to 15thDay
16%5%9%22%26%19%
1650
16th to endDay
18%410%22%26%17%
1760
November1st to 15thDay
26%6%12%23%23%7%
1642
16th to endDay
30%7%11%20%25%4
1590
December1st to 15thDay
41%6%11%15%18%4
1440
16th to endDay
39%9%13%17%15%4
1536
January1st to 15thNight
32%6%13%21%18%7%
2410
16th to endNight
34%8%11%13%19%13%
2496
February1st to 15thNight
34%6%10%22%17%7%
2247
16th to endNight
30%9%14%25%16%4
1895
March1st to 15thNight
32%9%13%18%17%7%
2046
16th to endNight
30%9%13%19%19%6%
2061
April1st to 15thNight
28%9%14%24%17%4
1799
16th to endNight
17%8%15%24%25%9%
1800
May1st to 15thNight
14%7%10%21%30%15%
1749
16th to endNight
10%9%14%24%31%9%
1496
June1st to 15thNight
13%7%9%19%25%24%
1440
16th to endNight
34410%32%44%
1440
July1st to 15thNight
5%247%21%59%
1366
16th to endNight
7%46%8%22%51%
1593
August1st to 15thNight
6%35%11%27%44%
1677
16th to endNight
42410%29%47%
1910
September1st to 15thNight
7%449%27%47%
1800
16th to endNight
8%5%5%17%35%27%
1805
October1st to 15thNight
18%6%8%21%23%21%
1980
16th to endNight
16%6%6%24%26%19%
2112
November1st to 15thNight
19%6%13%22%28%9%
2217
16th to endNight
25%7%11%20%27%8%
2368
December1st to 15thNight
35%8%10%18%20%6%
2520
16th to endNight
36%7%14%17%18%6%
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%7%31%24%17%5%
153
16th to endDay
11%11%20%25%26%5%
256
February1st to 15thDay
17%8%17%24%25%6%
243
16th to endDay
13%13%24%28%17%2
238
March1st to 15thDay
10%15%24%26%17%6%
270
16th to endDay
10%14%29%30%12%2
288
April1st to 15thDay
11%18%30%24%12%1
269
16th to endDay
7%18%32%28%10%2
270
May1st to 15thDay
214%34%34%11%3
288
16th to endDay
411%28%34%15%5%
330
June1st to 15thDay
311%36%31%12%4
315
16th to endDay
420%39%26%7%
315
July1st to 15thDay
17%45%27%8%
305
16th to endDay
114%43%28%11%
327
August1st to 15thDay
2220%41%23%9%
315
16th to endDay
112%36%33%16%
332
September1st to 15thDay
215%40%28%13%
315
16th to endDay
26%15%27%34%14%
264
October1st to 15thDay
37%23%31%24%9%
255
16th to endDay
5%6%17%32%28%8%
272
November1st to 15thDay
6%5%14%16%40%16%
148
16th to endDay
8%7%20%35%29%
85
December1st to 15thDay
11%10%33%26%18%
60
16th to endDay
7%17%10%31%26%6%
64
January1st to 15thNight
10%410%34%28%11%
720
16th to endNight
12%411%32%28%10%
768
February1st to 15thNight
12%412%32%27%10%
704
16th to endNight
10%6%17%35%23%6%
632
March1st to 15thNight
9%5%17%32%27%8%
720
16th to endNight
7%6%21%34%25%4
768
April1st to 15thNight
7%8%21%36%21%4
719
16th to endNight
36%26%32%24%6%
720
May1st to 15thNight
1323%42%24%5%
669
16th to endNight
2421%41%28%2
375
June1st to 15thNight
1120%48%24%3
360
16th to endNight
12%50%33%2
360
July1st to 15thNight
444%45%4
346
16th to endNight
333%49%12%
564
August1st to 15thNight
6%43%43%5%
604
16th to endNight
5%37%48%8%
764
September1st to 15thNight
17%35%45%9%
720
16th to endNight
2110%30%41%13%
667
October1st to 15thNight
4311%35%31%13%
660
16th to endNight
5%29%31%31%19%
704
November1st to 15thNight
5%211%33%33%14%
700
16th to endNight
5%313%31%32%12%
720
December1st to 15thNight
10%5%14%35%27%8%
720
16th to endNight
14%7%15%33%25%4
768
Page generated at 2017-09-19 04:32:21. Version ac04

Copyright 2017 A. Danko


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