Pineland Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pineland Observatory clear sky chart from 2005-11-06 to 2024-01-15.

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%
24574
13%
74553
11%
24527
69%
24527
16%
56307

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 10thNight
62%
757
14%
2459
13%
757
66%
757
16%
1803
January11th to 20thNight
58%
737
13%
2393
13%
737
61%
737
14%
1797
January21st to endNight
54%
792
16%
2394
14%
792
57%
792
17%
1786
February1st to 10thNight
57%
720
15%
2160
13%
720
60%
720
17%
1625
February11th to 20thNight
65%
700
15%
2098
12%
699
69%
699
18%
1541
February21st to endNight
69%
592
23%
1682
18%
592
73%
592
23%
1165
March1st to 10thNight
68%
720
21%
1980
14%
720
74%
720
27%
1344
March11th to 20thNight
67%
720
20%
1980
16%
720
71%
720
23%
1397
March21st to endNight
70%
792
21%
2178
17%
792
71%
792
24%
1507
April1st to 10thNight
72%
720
16%
1980
13%
720
74%
720
22%
1404
April11th to 20thNight
70%
711
15%
1953
12%
711
72%
711
22%
1387
April21st to endNight
72%
720
18%
1841
11%
720
74%
720
23%
1345
May1st to 10thNight
83%
626
20%
1706
17%
626
83%
626
27%
1162
May11th to 20thNight
74%
531
12%
1592
10%
531
75%
531
18%
1175
May21st to endNight
76%
582
11%
1745
10%
582
77%
582
16%
1327
June1st to 10thNight
69%
540
8%
1620
8%
540
69%
540
12%
1314
June11th to 20thNight
75%
540
8%
1620
7%
540
75%
540
15%
1253
June21st to endNight
77%
540
6%
1620
5%
540
77%
540
11%
1350
July1st to 10thNight
75%
525
4%
1575
4%
525
75%
525
11%
1318
July11th to 20thNight
77%
522
3%
1566
3%
522
77%
522
10%
1340
July21st to endNight
78%
591
5%
1672
5%
558
79%
558
11%
1403
August1st to 10thNight
74%
537
3%
1628
3%
534
74%
534
13%
1329
August11th to 20thNight
75%
570
3%
1812
3%
570
75%
570
10%
1479
August21st to endNight
64%
792
4%
2178
4%
792
64%
792
8%
1867
September1st to 10thNight
71%
720
3%
1980
2%
720
71%
720
10%
1642
September11th to 20thNight
66%
720
5%
1980
5%
720
66%
720
10%
1678
September21st to endNight
64%
720
6%
1980
5%
720
64%
720
10%
1674
October1st to 10thNight
68%
720
13%
1980
12%
720
69%
720
16%
1532
October11th to 20thNight
67%
720
14%
2124
14%
720
69%
720
14%
1651
October21st to endNight
63%
792
16%
2376
16%
792
65%
792
17%
1746
November1st to 10thNight
64%
740
18%
2221
16%
740
68%
740
17%
1647
November11th to 20thNight
62%
760
18%
2280
16%
760
65%
760
17%
1681
November21st to endNight
63%
760
15%
2332
15%
760
66%
760
16%
1716
December1st to 10thNight
65%
760
16%
2470
16%
760
68%
760
17%
1792
December11th to 20thNight
60%
759
16%
2927
12%
758
62%
758
12%
2058
December21st to endNight
64%
826
10%
4471
16%
817
67%
817
10%
3072

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
7%425%6%46%6%7%11%43%
74837
Night
7%5%25%6%45%6%7%10%44%
74937
TransparencyDay
23%40%12%13%9%3
74560
Night
23%40%11%13%10%3
74733
SeeingDay
7%29%22%34%26%
14472
Night
8%212%30%34%15%
24593

By Month

Percentage Cloud Cover SE (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 10thDay
8%5%35%4245%6%9%48%
1706
11th to 20thDay
8%4344245%7%11%49%
1656
21st to endDay
9%5%25%5%35%5%5%8%48%
1958
February1st to 10thDay
9%5%34435%46%7%52%
1800
11th to 20thDay
5%31431345%8%62%
1748
21st to endDay
5%4224335%5%11%56%
1572
March1st to 10thDay
321332445%8%65%
1980
11th to 20thDay
6%313325%45%9%58%
1980
21st to endDay
432342445%7%60%
2178
April1st to 10thDay
5%22332447%11%59%
1980
11th to 20thDay
7%3245%345%6%11%51%
1956
21st to endDay
42144245%5%9%58%
2116
May1st to 10thDay
311232345%9%68%
2266
11th to 20thDay
7%4245%35%5%7%12%46%
2301
21st to endDay
6%4245%46%6%7%10%45%
2531
June1st to 10thDay
11%6%37%6%46%7%7%11%32%
2340
11th to 20thDay
7%425%6%46%7%10%15%34%
2340
21st to endDay
6%5%36%7%5%8%8%9%14%29%
2340
July1st to 10thDay
7%426%8%5%8%9%9%14%28%
2340
11th to 20thDay
5%5%36%7%5%9%9%10%15%26%
2340
21st to endDay
6%436%9%6%9%10%10%13%24%
2547
August1st to 10thDay
5%425%8%5%9%8%10%14%29%
2292
11th to 20thDay
6%5%27%8%6%9%8%10%13%27%
2071
21st to endDay
8%6%36%8%5%8%8%9%12%27%
2178
September1st to 10thDay
6%426%9%5%8%8%11%14%28%
1980
11th to 20thDay
9%5%37%7%5%8%8%8%11%31%
1980
21st to endDay
8%5%36%8%5%7%8%8%11%31%
1980
October1st to 10thDay
6%6%37%7%46%6%7%9%40%
1980
11th to 20thDay
8%5%25%6%35%5%7%8%45%
1834
21st to endDay
8%5%24435%6%7%8%49%
1980
November1st to 10thDay
7%42342446%8%55%
1857
11th to 20thDay
8%425%5%345%6%10%48%
1900
21st to endDay
6%3245%35%5%6%11%50%
1843
December1st to 10thDay
7%425%5%346%6%9%51%
1710
11th to 20thDay
9%425%435%5%7%8%48%
2153
21st to endDay
10%6%37%7%46%5%8%9%35%
3124
January1st to 10thNight
8%5%25%435%6%7%9%46%
2459
11th to 20thNight
8%5%245%35%5%7%10%45%
2393
21st to endNight
10%5%35%4445%7%8%44%
2394
February1st to 10thNight
9%6%25%6%4445%7%48%
2160
11th to 20thNight
7%32443446%8%54%
2098
21st to endNight
6%3145%35%45%8%57%
1682
March1st to 10thNight
431242346%9%62%
1980
11th to 20thNight
5%4235%4445%9%55%
1980
21st to endNight
32245%235%6%9%58%
2178
April1st to 10thNight
5%3134345%7%10%55%
1980
11th to 20thNight
5%4245%35%5%6%9%52%
1953
21st to endNight
44145%35%5%6%9%53%
1841
May1st to 10thNight
22133346%5%9%62%
1706
11th to 20thNight
8%425%5%45%5%7%8%47%
1592
21st to endNight
7%5%15%5%35%5%8%9%47%
1744
June1st to 10thNight
12%6%26%6%45%7%8%10%33%
1620
11th to 20thNight
5%426%7%47%7%9%12%38%
1620
21st to endNight
5%437%6%5%7%8%12%13%31%
1620
July1st to 10thNight
6%5%36%7%47%8%8%13%33%
1620
11th to 20thNight
5%5%36%8%5%7%9%10%14%29%
1620
21st to endNight
4325%8%5%7%9%12%14%30%
1771
August1st to 10thNight
5%6%36%8%47%8%9%14%31%
1639
11th to 20thNight
6%5%35%6%6%6%8%10%14%29%
1812
21st to endNight
10%6%38%7%5%7%7%9%12%26%
2178
September1st to 10thNight
5%437%8%5%7%8%9%15%29%
1980
11th to 20thNight
9%6%37%6%5%7%7%9%11%30%
1980
21st to endNight
10%6%48%7%47%7%8%11%28%
1980
October1st to 10thNight
8%5%25%8%35%6%8%9%42%
1980
11th to 20thNight
7%5%26%5%46%6%6%9%44%
2124
21st to endNight
9%5%25%6%35%5%6%8%47%
2376
November1st to 10thNight
8%425%5%25%5%5%8%51%
2221
11th to 20thNight
8%5%25%5%35%45%8%49%
2280
21st to endNight
8%425%6%345%6%9%49%
2332
December1st to 10thNight
6%425%5%45%46%9%50%
2470
11th to 20thNight
10%5%25%43445%8%50%
3042
21st to endNight
10%7%36%6%46%6%7%10%37%
4532

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 10thDay
20%40%8%16%12%4
1707
11th to 20thDay
19%42%8%16%10%5%
1656
21st to endDay
21%39%9%16%10%6%
1958
February1st to 10thDay
23%37%6%13%15%6%
1800
11th to 20thDay
16%39%10%18%12%5%
1758
21st to endDay
14%36%10%13%22%5%
1572
March1st to 10thDay
11%37%10%19%18%5%
1980
11th to 20thDay
14%38%11%20%14%4
1980
21st to endDay
13%37%10%21%15%3
2178
April1st to 10thDay
14%38%14%20%10%4
1980
11th to 20thDay
17%38%12%20%12%2
1956
21st to endDay
15%37%11%16%18%3
2116
May1st to 10thDay
7%36%12%26%18%1
2266
11th to 20thDay
18%40%15%16%10%
2305
21st to endDay
23%40%12%17%6%1
2531
June1st to 10thDay
29%40%18%11%3
2340
11th to 20thDay
24%40%20%13%2
2340
21st to endDay
31%43%16%8%1
2340
July1st to 10thDay
30%46%17%6%1
2275
11th to 20thDay
32%44%17%6%
2271
21st to endDay
28%48%15%8%
2405
August1st to 10thDay
28%46%19%6%1
2279
11th to 20thDay
31%44%19%7%
2071
21st to endDay
33%45%14%6%1
2178
September1st to 10thDay
27%47%19%7%1
1980
11th to 20thDay
32%44%14%9%2
1980
21st to endDay
30%43%14%9%31
1980
October1st to 10thDay
24%40%12%11%9%4
1980
11th to 20thDay
24%39%10%14%9%3
1834
21st to endDay
20%40%9%12%16%4
1980
November1st to 10thDay
17%41%5%12%14%10%
1857
11th to 20thDay
17%41%8%17%13%4
1900
21st to endDay
18%40%10%17%12%4
1843
December1st to 10thDay
18%42%10%17%10%4
1710
11th to 20thDay
23%35%9%15%11%7%
2150
21st to endDay
34%28%10%12%13%3
3124
January1st to 10thNight
19%42%8%17%11%4
2459
11th to 20thNight
22%42%8%14%10%4
2393
21st to endNight
23%38%9%14%11%4
2394
February1st to 10thNight
24%38%6%11%14%6%
2160
11th to 20thNight
21%38%8%16%11%5%
2099
21st to endNight
16%37%7%15%19%5%
1682
March1st to 10thNight
12%37%6%22%18%5%
1980
11th to 20thNight
17%37%9%20%13%4
1980
21st to endNight
14%38%9%21%14%3
2178
April1st to 10thNight
16%38%13%19%11%3
1980
11th to 20thNight
18%37%12%17%13%3
1953
21st to endNight
17%39%9%16%17%3
1841
May1st to 10thNight
11%38%10%23%17%2
1706
11th to 20thNight
20%40%14%17%9%
1593
21st to endNight
22%42%11%16%9%
1745
June1st to 10thNight
29%42%12%13%4
1620
11th to 20thNight
23%42%19%13%3
1620
21st to endNight
30%44%15%7%3
1620
July1st to 10thNight
30%44%18%7%1
1575
11th to 20thNight
30%47%17%5%1
1566
21st to endNight
25%49%17%9%
1672
August1st to 10thNight
26%45%21%8%1
1628
11th to 20thNight
29%44%21%5%
1812
21st to endNight
34%45%15%6%
2178
September1st to 10thNight
28%46%20%6%1
1980
11th to 20thNight
32%44%14%9%1
1980
21st to endNight
34%41%13%7%4
1980
October1st to 10thNight
24%41%12%10%9%4
1980
11th to 20thNight
26%40%9%12%9%3
2124
21st to endNight
22%39%8%14%14%3
2376
November1st to 10thNight
20%41%5%12%15%8%
2221
11th to 20thNight
19%41%7%15%13%4
2280
21st to endNight
21%40%8%15%13%3
2332
December1st to 10thNight
19%41%9%16%12%4
2470
11th to 20thNight
25%35%7%16%11%8%
3044
21st to endNight
32%29%13%11%13%3
4532

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 10thDay
8%319%38%28%4
270
11th to 20thDay
9%6%19%30%30%7%
252
21st to endDay
11%6%19%39%23%2
264
February1st to 10thDay
45%15%32%34%9%
240
11th to 20thDay
3210%32%44%9%
240
21st to endDay
5%214%37%35%8%
290
March1st to 10thDay
3119%45%29%4
420
11th to 20thDay
7%314%39%30%6%
420
21st to endDay
314%42%35%6%
462
April1st to 10thDay
4114%42%34%4
420
11th to 20thDay
7%215%35%34%7%
412
21st to endDay
5%10%37%40%7%
420
May1st to 10thDay
4435%45%12%
423
11th to 20thDay
9%7%24%44%16%
447
21st to endDay
7%6%16%39%32%
485
June1st to 10thDay
13%7%15%39%26%
450
11th to 20thDay
7%137%40%42%
450
21st to endDay
3137%29%57%
450
July1st to 10thDay
5%2326%64%
445
11th to 20thDay
4115%26%64%
444
21st to endDay
6%149%28%52%
488
August1st to 10thDay
5%16%29%59%
446
11th to 20thDay
6%115%29%59%
439
21st to endDay
10%139%30%46%
495
September1st to 10thDay
6%228%30%53%
450
11th to 20thDay
7%410%32%46%
450
21st to endDay
8%1310%35%44%
450
October1st to 10thDay
8%18%19%43%21%
450
11th to 20thDay
8%27%22%43%18%
450
21st to endDay
8%29%23%39%17%
495
November1st to 10thDay
7%311%28%36%15%
455
11th to 20thDay
10%411%31%35%9%
460
21st to endDay
6%213%31%35%12%
403
December1st to 10thDay
9%117%26%33%14%
270
11th to 20thDay
7%415%30%36%10%
270
21st to endDay
6%5%12%27%38%11%
297
January1st to 10thNight
10%417%40%26%3
760
11th to 20thNight
10%5%20%37%26%2
737
21st to endNight
10%6%23%38%22%1
792
February1st to 10thNight
12%320%38%26%2
720
11th to 20thNight
7%318%40%29%3
703
21st to endNight
6%215%40%35%2
592
March1st to 10thNight
4322%43%26%3
720
11th to 20thNight
7%217%39%34%2
720
21st to endNight
3217%45%30%3
792
April1st to 10thNight
4215%43%33%3
720
11th to 20thNight
4315%47%28%3
711
21st to endNight
6%212%44%34%3
720
May1st to 10thNight
319%41%41%6%
626
11th to 20thNight
7%19%34%43%7%
531
21st to endNight
7%15%27%49%12%
584
June1st to 10thNight
14%26%16%44%19%
540
11th to 20thNight
5%148%45%37%
540
21st to endNight
6%129%36%46%
540
July1st to 10thNight
6%27%28%56%
525
11th to 20thNight
4118%33%53%
522
21st to endNight
428%31%54%
591
August1st to 10thNight
5%137%39%46%
537
11th to 20thNight
7%27%32%52%
570
21st to endNight
11%1415%35%34%
792
September1st to 10thNight
5%312%43%37%
720
11th to 20thNight
10%1416%38%31%
720
21st to endNight
13%15%18%41%23%
720
October1st to 10thNight
10%18%32%39%11%
720
11th to 20thNight
7%212%30%37%12%
720
21st to endNight
12%213%33%33%8%
792
November1st to 10thNight
8%217%39%30%5%
740
11th to 20thNight
9%317%37%29%5%
760
21st to endNight
8%216%39%31%3
760
December1st to 10thNight
7%218%33%36%5%
760
11th to 20thNight
9%419%34%29%5%
760
21st to endNight
8%417%35%32%4
836
Page generated at 2024-01-11 22:33:46. Version ac07

Copyright 2024 Attilla Danko


Pineland Observatory Clear Sky Chart |Charts Home