Breezy Point Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Breezy Point Observatory clear sky chart from 2005-11-06 to 2024-01-12.

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
39%
24015
17%
74537
12%
23965
45%
23965
21%
51050

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
18%
759
13%
2459
6%
757
26%
757
10%
1891
January11th to 20thNight
18%
727
11%
2360
5%
727
25%
727
10%
1836
January21st to endNight
18%
792
14%
2574
6%
792
28%
792
12%
1925
February1st to 10thNight
23%
720
12%
2340
8%
720
29%
720
13%
1757
February11th to 20thNight
15%
701
12%
2162
5%
700
23%
700
12%
1626
February21st to endNight
18%
592
15%
1776
6%
592
27%
592
13%
1345
March1st to 10thNight
25%
720
19%
2016
10%
720
33%
720
20%
1406
March11th to 20thNight
25%
720
17%
1980
8%
720
32%
720
19%
1425
March21st to endNight
25%
792
16%
2178
8%
792
32%
792
19%
1582
April1st to 10thNight
27%
720
16%
1978
7%
720
35%
720
22%
1358
April11th to 20thNight
33%
613
21%
1677
9%
613
42%
613
27%
1108
April21st to endNight
30%
540
20%
1620
9%
540
39%
540
22%
1088
May1st to 10thNight
35%
540
15%
1620
8%
540
41%
540
20%
1136
May11th to 20thNight
39%
531
16%
1593
9%
531
44%
531
21%
1113
May21st to endNight
55%
582
17%
1745
12%
582
59%
582
30%
1098
June1st to 10thNight
56%
540
18%
1620
16%
540
59%
540
32%
996
June11th to 20thNight
56%
540
15%
1620
13%
540
59%
540
28%
1032
June21st to endNight
58%
540
17%
1620
15%
540
61%
540
31%
995
July1st to 10thNight
61%
525
15%
1575
13%
525
63%
525
28%
1017
July11th to 20thNight
63%
522
17%
1566
13%
522
66%
522
32%
956
July21st to endNight
62%
591
18%
1672
16%
558
64%
558
28%
1080
August1st to 10thNight
65%
537
19%
1600
17%
534
65%
534
29%
1024
August11th to 20thNight
63%
534
21%
1598
19%
534
65%
534
27%
1036
August21st to endNight
63%
638
24%
1826
19%
638
66%
638
35%
1086
September1st to 10thNight
62%
720
23%
1944
16%
720
65%
720
36%
1198
September11th to 20thNight
62%
720
27%
1980
20%
720
66%
720
39%
1167
September21st to endNight
51%
720
25%
1980
19%
720
57%
720
29%
1287
October1st to 10thNight
53%
720
23%
2078
20%
720
58%
720
33%
1263
October11th to 20thNight
40%
720
23%
2160
17%
720
51%
720
27%
1372
October21st to endNight
37%
792
24%
2376
19%
792
45%
792
23%
1585
November1st to 10thNight
43%
740
26%
2352
21%
740
52%
740
29%
1404
November11th to 20thNight
32%
760
21%
2470
14%
760
42%
760
19%
1636
November21st to endNight
33%
760
20%
2470
13%
760
42%
760
19%
1699
December1st to 10thNight
23%
760
13%
2470
9%
760
29%
760
12%
1888
December11th to 20thNight
25%
759
13%
3000
9%
759
31%
759
11%
2189
December21st to endNight
23%
828
8%
4482
7%
817
30%
817
7%
3446

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%8%36%6%35%5%5%7%35%
74895
Night
16%9%36%5%3445%7%37%
74834
TransparencyDay
48%6%11%20%13%2
74617
Night
47%6%11%20%14%2
74631
SeeingDay
22%12%26%22%13%5%
13877
Night
21%10%25%28%15%2
24029

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
18%14%5%10%8%35%445%23%
1706
11th to 20thDay
21%16%6%11%6%33445%22%
1629
21st to endDay
20%15%6%9%7%3434424%
1782
February1st to 10thDay
23%13%6%8%6%33345%27%
1620
11th to 20thDay
21%13%5%10%5%44445%26%
1683
21st to endDay
23%12%47%424445%30%
1480
March1st to 10thDay
18%9%47%5%23446%37%
1944
11th to 20thDay
20%9%5%7%6%34446%31%
1980
21st to endDay
21%10%47%6%345%46%32%
2178
April1st to 10thDay
15%9%46%6%345%5%7%36%
1981
11th to 20thDay
17%8%36%5%2435%7%40%
2247
21st to endDay
19%7%35%6%3446%6%35%
2340
May1st to 10thDay
19%7%47%6%45%5%5%7%30%
2340
11th to 20thDay
20%7%37%6%445%5%7%32%
2301
21st to endDay
11%5%25%7%46%5%8%9%38%
2531
June1st to 10thDay
14%5%25%6%35%6%6%8%40%
2340
11th to 20thDay
10%6%35%6%46%7%7%9%37%
2340
21st to endDay
11%6%35%6%46%6%7%11%36%
2340
July1st to 10thDay
11%5%26%6%46%6%7%9%37%
2340
11th to 20thDay
11%426%6%47%7%7%9%38%
2340
21st to endDay
13%6%36%5%36%6%6%10%36%
2547
August1st to 10thDay
10%5%25%6%5%6%8%8%11%33%
2327
11th to 20thDay
11%6%35%6%46%6%8%10%34%
2303
21st to endDay
10%5%25%6%45%6%5%9%42%
2512
September1st to 10thDay
14%5%245%346%5%7%45%
2013
11th to 20thDay
11%6%25%5%3446%7%47%
1980
21st to endDay
18%6%25%5%34446%42%
1980
October1st to 10thDay
13%6%25%4345%5%8%43%
1882
11th to 20thDay
18%6%25%5%3445%6%43%
1800
21st to endDay
22%7%26%434346%40%
1980
November1st to 10thDay
13%5%25%433445%51%
1722
11th to 20thDay
16%11%36%5%3435%6%37%
1710
21st to endDay
18%9%46%5%35%45%5%36%
1710
December1st to 10thDay
25%15%48%6%34345%24%
1710
11th to 20thDay
21%15%7%8%42335%5%28%
2153
21st to endDay
21%18%5%9%6%35%5%5%6%17%
3124
January1st to 10thNight
17%14%5%9%7%45%5%45%25%
2459
11th to 20thNight
23%14%5%9%5%34435%24%
2360
21st to endNight
19%15%5%7%6%35%445%28%
2574
February1st to 10thNight
23%12%5%8%6%34445%27%
2340
11th to 20thNight
23%12%5%7%5%35%345%28%
2160
21st to endNight
23%14%5%6%434346%28%
1776
March1st to 10thNight
17%9%46%6%34445%37%
2016
11th to 20thNight
21%9%36%6%3345%7%33%
1980
21st to endNight
21%10%37%5%34345%35%
2178
April1st to 10thNight
16%10%35%5%3445%7%38%
1978
11th to 20thNight
15%7%35%43445%9%40%
1677
21st to endNight
16%7%36%6%3445%7%39%
1620
May1st to 10thNight
16%7%36%7%45%5%5%8%35%
1620
11th to 20thNight
18%6%46%6%345%5%9%34%
1592
21st to endNight
11%5%25%435%5%6%10%44%
1744
June1st to 10thNight
10%4245%45%5%7%9%46%
1620
11th to 20thNight
9%5%35%5%35%5%7%11%41%
1620
21st to endNight
10%5%25%5%345%7%9%44%
1620
July1st to 10thNight
10%5%36%5%35%5%7%9%42%
1620
11th to 20thNight
9%5%25%5%26%5%6%9%47%
1620
21st to endNight
10%5%25%5%36%6%7%9%41%
1771
August1st to 10thNight
8%436%6%46%5%6%8%44%
1611
11th to 20thNight
10%5%26%6%5%6%46%9%42%
1598
21st to endNight
9%4345%3446%10%47%
1826
September1st to 10thNight
12%4245%345%5%7%50%
1944
11th to 20thNight
9%4245%3345%7%54%
1980
21st to endNight
15%5%25%5%335%5%6%45%
1980
October1st to 10thNight
12%5%244345%5%7%48%
2078
11th to 20thNight
16%6%25%4345%46%45%
2160
21st to endNight
22%5%35%43435%5%41%
2376
November1st to 10thNight
12%6%35%443445%50%
2352
11th to 20thNight
17%10%35%5%345%47%37%
2470
21st to endNight
18%10%46%435%446%36%
2470
December1st to 10thNight
23%13%5%8%6%33445%26%
2470
11th to 20thNight
18%15%6%7%5%345%45%28%
3042
21st to endNight
19%18%6%8%7%35%446%20%
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
64%49%16%7%
1707
11th to 20thDay
66%410%15%4
1629
21st to endDay
64%49%14%7%1
1782
February1st to 10thDay
62%410%17%7%1
1620
11th to 20thDay
61%49%16%8%1
1692
21st to endDay
58%48%19%9%1
1480
March1st to 10thDay
50%38%27%10%1
1944
11th to 20thDay
53%5%9%18%12%2
1980
21st to endDay
54%6%9%19%10%2
2178
April1st to 10thDay
47%7%10%20%13%4
1981
11th to 20thDay
45%5%10%19%17%4
2247
21st to endDay
49%7%12%19%11%3
2340
May1st to 10thDay
52%7%10%20%10%2
2340
11th to 20thDay
51%7%11%18%11%2
2305
21st to endDay
40%9%15%21%13%1
2531
June1st to 10thDay
40%8%12%22%16%2
2340
11th to 20thDay
40%10%13%20%16%2
2340
21st to endDay
40%9%14%22%13%2
2340
July1st to 10thDay
41%11%12%18%15%2
2275
11th to 20thDay
39%10%13%22%14%2
2271
21st to endDay
41%8%13%22%13%2
2405
August1st to 10thDay
41%11%14%23%11%1
2314
11th to 20thDay
41%11%11%25%11%1
2303
21st to endDay
38%7%14%21%16%4
2512
September1st to 10thDay
38%6%10%20%21%6%
2013
11th to 20thDay
35%6%11%26%20%2
1980
21st to endDay
43%411%21%20%1
1980
October1st to 10thDay
38%5%13%23%20%2
1882
11th to 20thDay
43%5%9%25%18%1
1800
21st to endDay
47%48%23%17%1
1980
November1st to 10thDay
36%5%9%29%17%4
1722
11th to 20thDay
48%47%21%16%3
1710
21st to endDay
50%5%10%21%14%1
1710
December1st to 10thDay
64%48%19%41
1710
11th to 20thDay
60%49%18%9%
2150
21st to endDay
68%6%11%12%4
3124
January1st to 10thNight
63%49%15%9%1
2459
11th to 20thNight
63%5%10%15%6%1
2360
21st to endNight
59%5%10%19%7%2
2574
February1st to 10thNight
59%5%10%18%7%1
2340
11th to 20thNight
60%47%17%11%1
2162
21st to endNight
59%5%9%16%9%3
1776
March1st to 10thNight
49%49%22%14%1
2016
11th to 20thNight
51%5%10%20%13%1
1980
21st to endNight
53%48%19%14%3
2178
April1st to 10thNight
46%5%9%20%16%3
1978
11th to 20thNight
41%5%12%19%17%6%
1677
21st to endNight
45%5%10%20%17%2
1620
May1st to 10thNight
47%8%11%19%12%3
1620
11th to 20thNight
47%8%11%18%13%3
1593
21st to endNight
35%9%16%26%14%1
1745
June1st to 10thNight
33%8%12%26%17%3
1620
11th to 20thNight
35%10%15%19%18%2
1620
21st to endNight
34%8%14%24%17%2
1620
July1st to 10thNight
37%9%13%22%17%2
1575
11th to 20thNight
33%8%15%22%18%3
1566
21st to endNight
36%10%11%25%16%1
1672
August1st to 10thNight
37%8%14%25%15%2
1600
11th to 20thNight
38%9%12%23%17%1
1598
21st to endNight
32%7%14%25%19%5%
1826
September1st to 10thNight
32%7%13%21%20%7%
1944
11th to 20thNight
30%6%12%25%24%3
1980
21st to endNight
38%7%10%20%22%2
1980
October1st to 10thNight
35%5%12%25%19%3
2078
11th to 20thNight
40%6%9%23%20%2
2160
21st to endNight
46%47%24%16%3
2376
November1st to 10thNight
37%410%22%22%5%
2352
11th to 20thNight
47%49%19%18%3
2470
21st to endNight
50%5%9%22%13%1
2470
December1st to 10thNight
61%5%8%19%6%1
2470
11th to 20thNight
58%5%10%18%8%1
3044
21st to endNight
65%5%10%15%6%
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
30%22%33%11%31
270
11th to 20thDay
35%23%33%9%1
243
21st to endDay
33%28%25%10%3
264
February1st to 10thDay
37%23%28%10%3
240
11th to 20thDay
43%25%27%5%
240
21st to endDay
34%24%33%9%1
198
March1st to 10thDay
30%21%31%15%4
384
11th to 20thDay
28%21%30%15%6%1
420
21st to endDay
32%15%31%18%41
462
April1st to 10thDay
25%19%28%19%8%1
420
11th to 20thDay
26%16%27%20%8%4
412
21st to endDay
30%17%28%16%8%2
420
May1st to 10thDay
27%14%31%16%8%4
423
11th to 20thDay
21%11%32%21%11%3
447
21st to endDay
13%8%26%28%16%8%
485
June1st to 10thDay
16%7%24%28%18%6%
450
11th to 20thDay
14%9%24%30%17%6%
450
21st to endDay
13%8%28%29%16%6%
450
July1st to 10thDay
12%323%24%20%18%
445
11th to 20thDay
10%5%23%32%20%10%
444
21st to endDay
16%5%20%28%20%10%
488
August1st to 10thDay
13%319%32%22%11%
446
11th to 20thDay
16%421%27%21%10%
439
21st to endDay
10%322%32%21%11%
495
September1st to 10thDay
15%419%25%26%11%
450
11th to 20thDay
12%416%29%28%12%
450
21st to endDay
21%8%22%24%20%5%
450
October1st to 10thDay
15%8%26%25%21%5%
450
11th to 20thDay
22%12%28%26%11%2
450
21st to endDay
28%13%28%21%8%2
495
November1st to 10thDay
19%14%32%22%9%3
320
11th to 20thDay
29%17%27%19%7%1
270
21st to endDay
22%23%32%18%41
270
December1st to 10thDay
32%19%30%15%31
270
11th to 20thDay
28%22%31%14%41
270
21st to endDay
34%21%27%13%4
297
January1st to 10thNight
26%20%30%19%4
760
11th to 20thNight
32%17%28%20%3
727
21st to endNight
27%18%30%22%3
792
February1st to 10thNight
30%12%30%27%2
720
11th to 20thNight
32%18%30%19%1
703
21st to endNight
33%14%31%20%2
592
March1st to 10thNight
26%14%30%24%5%
720
11th to 20thNight
28%15%27%21%8%1
720
21st to endNight
28%13%30%23%6%1
792
April1st to 10thNight
25%14%30%23%7%
720
11th to 20thNight
18%14%33%24%11%1
613
21st to endNight
18%10%36%30%7%
540
May1st to 10thNight
19%9%29%29%13%1
540
11th to 20thNight
19%5%29%29%16%2
531
21st to endNight
13%322%31%27%4
584
June1st to 10thNight
11%324%36%24%2
540
11th to 20thNight
11%321%38%26%2
540
21st to endNight
12%419%40%24%2
540
July1st to 10thNight
13%214%34%31%6%
525
11th to 20thNight
8%319%33%33%4
522
21st to endNight
11%315%33%34%5%
591
August1st to 10thNight
9%213%39%36%2
537
11th to 20thNight
12%212%37%32%6%
534
21st to endNight
12%116%33%32%6%
638
September1st to 10thNight
13%316%32%31%6%
720
11th to 20thNight
11%317%31%33%6%
720
21st to endNight
18%5%20%33%21%3
720
October1st to 10thNight
15%422%30%26%3
720
11th to 20thNight
19%7%29%29%14%1
720
21st to endNight
24%10%23%30%11%1
792
November1st to 10thNight
16%10%26%32%15%1
740
11th to 20thNight
24%14%24%28%9%1
760
21st to endNight
25%10%27%30%7%1
760
December1st to 10thNight
31%14%27%23%5%
760
11th to 20thNight
25%14%29%25%5%
760
21st to endNight
28%15%26%28%2
836
Page generated at 2024-01-09 07:14:45. Version ac07

Copyright 2024 Attilla Danko


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