Robert Moses State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Robert Moses State Park 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
33%
23167
13%
74610
6%
23124
40%
23124
12%
56967

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
19%
760
14%
2649
4%
757
31%
757
10%
1999
January11th to 20thNight
23%
739
11%
2583
5%
739
31%
739
7%
2058
January21st to endNight
18%
792
15%
2672
4%
792
32%
792
12%
1962
February1st to 10thNight
19%
720
10%
2276
2%
720
29%
720
10%
1765
February11th to 20thNight
17%
703
13%
2100
3%
700
29%
700
9%
1655
February21st to endNight
19%
592
18%
1776
6%
592
34%
592
11%
1357
March1st to 10thNight
22%
720
15%
2160
6%
720
34%
720
14%
1608
March11th to 20thNight
25%
720
13%
2099
5%
720
33%
720
12%
1654
March21st to endNight
22%
792
16%
1980
4%
792
30%
792
15%
1560
April1st to 10thNight
26%
720
12%
1800
3%
720
31%
720
13%
1447
April11th to 20thNight
31%
711
12%
1775
4%
711
35%
711
13%
1441
April21st to endNight
30%
662
14%
1742
4%
662
35%
662
14%
1369
May1st to 10thNight
27%
540
11%
1620
5%
540
33%
540
11%
1317
May11th to 20thNight
27%
457
13%
1519
6%
457
34%
457
11%
1179
May21st to endNight
45%
388
11%
1551
12%
388
49%
388
10%
1171
June1st to 10thNight
41%
360
11%
1440
10%
360
47%
360
11%
1097
June11th to 20thNight
52%
360
11%
1440
12%
360
56%
360
11%
1073
June21st to endNight
54%
360
9%
1440
11%
360
57%
360
11%
1089
July1st to 10thNight
52%
350
8%
1400
10%
350
54%
350
10%
1075
July11th to 20thNight
56%
348
10%
1392
12%
348
59%
348
11%
1042
July21st to endNight
57%
394
12%
1486
12%
372
61%
372
11%
1105
August1st to 10thNight
57%
476
11%
1540
8%
474
59%
474
13%
1146
August11th to 20thNight
56%
710
12%
1774
7%
710
57%
710
16%
1411
August21st to endNight
58%
792
10%
1980
4%
792
60%
792
16%
1591
September1st to 10thNight
48%
720
14%
1800
6%
720
52%
720
17%
1420
September11th to 20thNight
53%
720
19%
1912
12%
720
57%
720
19%
1417
September21st to endNight
44%
720
15%
1980
9%
720
49%
720
15%
1542
October1st to 10thNight
37%
720
11%
2020
7%
720
42%
720
14%
1589
October11th to 20thNight
40%
720
14%
2160
8%
720
47%
720
14%
1635
October21st to endNight
26%
792
11%
2555
5%
792
34%
792
11%
2000
November1st to 10thNight
36%
740
14%
2407
8%
740
44%
740
14%
1758
November11th to 20thNight
27%
760
16%
2470
10%
760
36%
760
12%
1874
November21st to endNight
28%
760
13%
2477
6%
760
37%
760
12%
1888
December1st to 10thNight
22%
760
11%
2660
3%
760
31%
760
9%
2034
December11th to 20thNight
21%
760
15%
3177
4%
759
32%
759
8%
2290
December21st to endNight
19%
829
8%
4798
3%
817
30%
817
6%
3349

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
16%6%25%5%345%5%8%42%
74799
Night
17%7%35%43445%7%42%
74978
TransparencyDay
27%38%9%15%10%1
74504
Night
28%37%8%15%10%1
74807
SeeingDay
18%10%28%28%13%3
13958
Night
20%10%31%28%10%1
23175

By Month

Percentage Cloud Cover NE (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
15%5%25%6%3445%7%44%
1517
11th to 20thDay
16%7%45%5%35%46%7%38%
1472
21st to endDay
15%7%26%44445%9%41%
1682
February1st to 10thDay
19%7%35%5%345%5%6%39%
1683
11th to 20thDay
16%5%36%5%34346%45%
1748
21st to endDay
20%8%26%5%25%45%6%37%
1480
March1st to 10thDay
14%6%36%43445%8%44%
1797
11th to 20thDay
15%6%35%5%346%6%8%40%
1858
21st to endDay
19%8%36%5%2435%6%39%
2376
April1st to 10thDay
17%7%36%4345%5%6%39%
2160
11th to 20thDay
18%6%25%43445%7%42%
2134
21st to endDay
20%6%244345%5%7%40%
2218
May1st to 10thDay
24%6%35%424448%36%
2340
11th to 20thDay
20%6%25%42446%8%39%
2391
21st to endDay
15%6%244245%6%11%41%
2725
June1st to 10thDay
18%5%245%345%6%9%38%
2520
11th to 20thDay
15%7%345%45%5%6%8%39%
2520
21st to endDay
11%5%35%5%345%6%9%44%
2520
July1st to 10thDay
11%5%35%5%35%6%7%9%42%
2520
11th to 20thDay
9%5%26%5%35%6%7%9%43%
2520
21st to endDay
13%5%35%6%35%5%7%8%40%
2744
August1st to 10thDay
11%6%245%35%6%7%10%42%
2368
11th to 20thDay
12%5%25%5%35%5%7%9%41%
2126
21st to endDay
13%435%5%35%5%6%8%43%
2376
September1st to 10thDay
14%5%26%43445%7%45%
2160
11th to 20thDay
13%5%2442435%7%51%
2048
21st to endDay
18%7%25%43345%6%42%
1980
October1st to 10thDay
21%6%24424437%42%
1936
11th to 20thDay
16%435%43446%7%46%
1800
21st to endDay
19%6%245%3445%7%41%
1800
November1st to 10thDay
15%5%25%5%24335%51%
1671
11th to 20thDay
17%6%35%323447%47%
1710
21st to endDay
15%6%3442445%7%45%
1701
December1st to 10thDay
20%5%25%435%5%5%8%38%
1520
11th to 20thDay
22%7%24322346%45%
1906
21st to endDay
18%10%36%6%45%46%7%33%
2772
January1st to 10thNight
17%6%34434346%46%
2649
11th to 20thNight
21%7%24435%45%6%40%
2583
21st to endNight
15%8%35%424447%46%
2672
February1st to 10thNight
16%10%35%42445%6%40%
2276
11th to 20thNight
19%7%25%43445%6%40%
2098
21st to endNight
20%7%24424445%43%
1776
March1st to 10thNight
16%6%3443435%6%46%
2150
11th to 20thNight
17%6%35%5%345%5%7%41%
2098
21st to endNight
18%8%35%43445%6%41%
1980
April1st to 10thNight
19%7%35%5%345%47%39%
1800
11th to 20thNight
19%7%35%5%24447%40%
1775
21st to endNight
19%8%35%424345%42%
1742
May1st to 10thNight
21%9%36%5%35%45%7%32%
1620
11th to 20thNight
20%9%35%5%35%45%6%35%
1518
21st to endNight
18%7%26%5%345%6%7%37%
1550
June1st to 10thNight
20%5%245%25%45%8%38%
1440
11th to 20thNight
16%6%25%43447%10%40%
1440
21st to endNight
11%436%5%36%5%7%9%41%
1440
July1st to 10thNight
12%7%36%5%35%6%6%9%38%
1440
11th to 20thNight
13%6%25%5%46%5%7%9%38%
1440
21st to endNight
11%6%35%435%5%6%11%41%
1574
August1st to 10thNight
8%5%25%5%35%7%8%9%43%
1550
11th to 20thNight
12%6%25%6%46%5%6%10%37%
1774
21st to endNight
14%5%245%25%5%6%9%44%
1980
September1st to 10thNight
15%5%26%436%5%6%6%43%
1800
11th to 20thNight
14%5%2442345%5%52%
1912
21st to endNight
19%5%26%434446%42%
1980
October1st to 10thNight
20%9%245%23346%40%
2020
11th to 20thNight
15%5%3443435%6%48%
2160
21st to endNight
21%6%35%424446%41%
2555
November1st to 10thNight
12%6%245%24445%50%
2407
11th to 20thNight
19%6%24323445%48%
2470
21st to endNight
15%4245%3445%6%48%
2477
December1st to 10thNight
21%6%25%434446%40%
2660
11th to 20thNight
20%6%2442345%5%44%
3288
21st to endNight
19%9%35%5%34445%39%
4884

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
26%39%9%18%6%
1518
11th to 20thDay
29%42%9%12%7%1
1472
21st to endDay
28%38%7%18%8%1
1682
February1st to 10thDay
29%36%7%16%11%1
1683
11th to 20thDay
27%37%8%17%9%1
1757
21st to endDay
32%36%7%14%10%2
1480
March1st to 10thDay
25%37%9%17%10%1
1800
11th to 20thDay
28%37%9%15%9%1
1858
21st to endDay
30%36%5%14%12%3
2376
April1st to 10thDay
26%38%7%14%12%3
2160
11th to 20thDay
28%37%8%14%10%2
2134
21st to endDay
28%37%7%13%12%3
2218
May1st to 10thDay
30%38%6%13%11%1
2340
11th to 20thDay
28%38%7%13%11%3
2395
21st to endDay
25%39%12%14%9%2
2725
June1st to 10thDay
27%40%9%15%8%1
2520
11th to 20thDay
28%39%9%16%6%1
2520
21st to endDay
25%40%11%15%8%
2520
July1st to 10thDay
25%41%10%14%9%1
2450
11th to 20thDay
23%40%9%17%9%2
2445
21st to endDay
24%42%9%14%10%1
2591
August1st to 10thDay
24%41%11%16%8%
2354
11th to 20thDay
25%38%9%16%10%1
2126
21st to endDay
27%40%8%11%12%2
2376
September1st to 10thDay
25%39%8%13%14%2
2160
11th to 20thDay
21%38%7%17%15%2
2048
21st to endDay
29%37%7%12%14%2
1980
October1st to 10thDay
27%37%7%16%13%
1936
11th to 20thDay
25%38%9%16%11%1
1800
21st to endDay
29%37%7%15%10%1
1800
November1st to 10thDay
21%41%8%15%13%1
1671
11th to 20thDay
24%40%9%14%11%2
1710
21st to endDay
27%41%8%17%7%1
1701
December1st to 10thDay
26%42%10%14%7%1
1520
11th to 20thDay
30%32%12%14%11%1
1906
21st to endDay
37%28%11%17%6%
2772
January1st to 10thNight
26%39%8%17%9%
2649
11th to 20thNight
30%41%8%14%6%1
2583
21st to endNight
25%36%7%18%12%1
2672
February1st to 10thNight
30%37%8%14%10%1
2276
11th to 20thNight
30%38%7%13%9%3
2100
21st to endNight
29%35%5%17%11%2
1776
March1st to 10thNight
25%36%9%17%10%2
2160
11th to 20thNight
30%38%7%14%8%3
2099
21st to endNight
29%36%6%14%12%3
1980
April1st to 10thNight
30%37%7%11%12%3
1800
11th to 20thNight
32%37%5%11%14%1
1775
21st to endNight
29%37%6%13%11%4
1742
May1st to 10thNight
34%38%5%11%10%2
1620
11th to 20thNight
29%39%7%11%12%2
1519
21st to endNight
28%39%9%13%9%2
1551
June1st to 10thNight
30%38%8%13%11%1
1440
11th to 20thNight
27%39%10%17%7%1
1440
21st to endNight
28%40%10%16%6%1
1440
July1st to 10thNight
29%40%9%14%7%1
1400
11th to 20thNight
26%41%7%16%9%1
1392
21st to endNight
24%42%9%15%9%2
1486
August1st to 10thNight
25%39%12%14%9%1
1540
11th to 20thNight
28%38%7%18%8%1
1774
21st to endNight
28%39%9%14%9%1
1980
September1st to 10thNight
27%38%7%15%13%1
1800
11th to 20thNight
22%37%7%17%15%2
1912
21st to endNight
28%37%5%13%15%2
1980
October1st to 10thNight
29%38%6%14%11%2
2020
11th to 20thNight
27%37%9%18%9%1
2160
21st to endNight
31%38%8%13%10%1
2555
November1st to 10thNight
21%41%8%15%13%2
2407
11th to 20thNight
26%39%7%16%11%1
2470
21st to endNight
25%40%9%17%9%1
2477
December1st to 10thNight
27%40%10%13%9%1
2660
11th to 20thNight
30%33%9%13%15%2
3288
21st to endNight
37%26%10%18%9%
4884

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
23%18%34%20%4
180
11th to 20thDay
17%26%35%18%4
168
21st to endDay
18%15%43%18%5%1
220
February1st to 10thDay
26%13%41%18%2
303
11th to 20thDay
20%18%40%20%2
416
21st to endDay
25%18%34%19%5%
346
March1st to 10thDay
14%18%39%25%4
420
11th to 20thDay
18%12%40%25%41
420
21st to endDay
23%15%36%19%7%1
462
April1st to 10thDay
21%15%37%18%9%1
420
11th to 20thDay
19%12%33%26%10%
412
21st to endDay
26%11%32%24%5%
420
May1st to 10thDay
28%10%30%24%7%1
423
11th to 20thDay
20%8%29%32%10%1
447
21st to endDay
17%420%34%22%3
485
June1st to 10thDay
19%5%22%33%18%3
450
11th to 20thDay
15%7%26%36%14%2
450
21st to endDay
12%426%35%20%3
450
July1st to 10thDay
13%217%38%25%4
445
11th to 20thDay
9%317%39%26%5%
444
21st to endDay
13%418%43%20%3
488
August1st to 10thDay
12%216%39%24%6%
446
11th to 20thDay
14%316%37%26%4
439
21st to endDay
12%420%38%19%7%
495
September1st to 10thDay
18%421%28%22%7%
450
11th to 20thDay
15%421%30%21%9%
450
21st to endDay
21%5%26%28%16%4
450
October1st to 10thDay
26%7%22%24%16%5%
450
11th to 20thDay
15%12%28%29%14%2
450
21st to endDay
22%12%32%24%10%1
405
November1st to 10thDay
15%12%25%34%11%2
365
11th to 20thDay
19%19%31%24%7%1
370
21st to endDay
17%15%32%26%8%1
361
December1st to 10thDay
19%18%37%19%7%1
180
11th to 20thDay
29%22%27%17%5%
180
21st to endDay
23%18%38%14%7%1
198
January1st to 10thNight
20%18%39%19%4
760
11th to 20thNight
26%15%32%25%2
739
21st to endNight
19%16%42%21%2
792
February1st to 10thNight
21%14%39%23%3
720
11th to 20thNight
24%17%39%19%2
703
21st to endNight
24%17%36%19%4
592
March1st to 10thNight
21%16%38%21%5%
720
11th to 20thNight
20%13%39%22%5%1
720
21st to endNight
21%12%39%22%5%
792
April1st to 10thNight
22%13%36%24%5%
720
11th to 20thNight
21%11%33%29%6%
711
21st to endNight
22%9%34%29%6%1
662
May1st to 10thNight
24%8%32%28%8%1
540
11th to 20thNight
22%9%35%28%5%
457
21st to endNight
21%418%38%17%2
389
June1st to 10thNight
20%425%33%17%
360
11th to 20thNight
18%419%44%16%
360
21st to endNight
11%222%50%14%1
360
July1st to 10thNight
12%322%42%19%2
350
11th to 20thNight
12%417%44%20%3
348
21st to endNight
14%218%47%18%1
394
August1st to 10thNight
10%220%47%20%1
476
11th to 20thNight
15%316%38%26%2
710
21st to endNight
14%416%38%25%4
792
September1st to 10thNight
16%323%37%17%4
720
11th to 20thNight
17%5%19%34%20%6%
720
21st to endNight
21%323%33%18%2
720
October1st to 10thNight
24%7%25%26%16%3
720
11th to 20thNight
17%10%29%31%12%1
720
21st to endNight
24%10%34%24%8%
792
November1st to 10thNight
15%11%33%28%11%2
740
11th to 20thNight
21%14%33%23%8%
760
21st to endNight
17%15%34%25%7%1
760
December1st to 10thNight
25%16%33%19%5%1
760
11th to 20thNight
22%15%36%22%4
760
21st to endNight
23%14%39%21%3
836
Page generated at 2024-01-12 07:31:50. Version ac07

Copyright 2024 Attilla Danko


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