Ocean City
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ocean City clear sky chart from 2005-11-06 to 2024-02-15.

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
41%
23463
20%
80095
12%
23379
50%
23379
22%
49991

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
23%
750
26%
4323
9%
737
43%
737
13%
2243
January11th to 20thNight
27%
760
25%
4271
10%
740
43%
740
13%
2439
January21st to endNight
25%
828
15%
4473
11%
814
42%
814
12%
2826
February1st to 10thNight
27%
760
18%
2448
10%
760
39%
760
21%
1536
February11th to 20thNight
17%
721
20%
2153
5%
718
35%
718
21%
1411
February21st to endNight
26%
592
26%
1776
11%
592
45%
592
23%
1133
March1st to 10thNight
30%
720
23%
2160
11%
720
44%
720
29%
1299
March11th to 20thNight
32%
720
21%
2020
11%
720
42%
720
26%
1341
March21st to endNight
31%
792
21%
2024
9%
792
40%
792
26%
1401
April1st to 10thNight
29%
720
20%
1800
6%
720
37%
720
26%
1224
April11th to 20thNight
43%
711
20%
1775
8%
711
48%
711
32%
1188
April21st to endNight
40%
720
18%
1800
7%
720
45%
720
28%
1267
May1st to 10thNight
40%
592
15%
1672
7%
592
44%
592
22%
1190
May11th to 20thNight
42%
420
17%
1482
13%
420
48%
420
18%
995
May21st to endNight
54%
388
14%
1551
14%
388
57%
388
18%
1010
June1st to 10thNight
53%
360
16%
1440
20%
360
56%
360
20%
904
June11th to 20thNight
60%
360
16%
1440
20%
360
63%
360
21%
889
June21st to endNight
67%
360
17%
1440
22%
360
69%
360
25%
834
July1st to 10thNight
64%
350
14%
1400
18%
350
66%
350
21%
857
July11th to 20thNight
70%
348
16%
1392
19%
348
71%
348
24%
797
July21st to endNight
66%
416
19%
1507
21%
393
70%
393
25%
896
August1st to 10thNight
67%
577
15%
1640
12%
574
67%
574
28%
1078
August11th to 20thNight
65%
710
17%
1774
10%
710
67%
710
33%
1188
August21st to endNight
68%
792
18%
1980
10%
792
69%
792
34%
1319
September1st to 10thNight
58%
720
22%
1800
13%
720
60%
720
31%
1217
September11th to 20thNight
63%
720
27%
1858
18%
720
67%
720
37%
1161
September21st to endNight
46%
720
21%
1980
16%
720
50%
720
23%
1380
October1st to 10thNight
47%
720
17%
2098
15%
720
51%
720
25%
1387
October11th to 20thNight
46%
720
26%
2160
19%
720
57%
720
30%
1319
October21st to endNight
37%
792
24%
2457
16%
792
49%
792
25%
1530
November1st to 10thNight
42%
740
24%
2407
16%
740
55%
740
29%
1380
November11th to 20thNight
32%
760
24%
2470
14%
760
47%
760
23%
1512
November21st to endNight
36%
760
25%
2503
14%
760
52%
760
26%
1479
December1st to 10thNight
25%
760
19%
2660
7%
760
40%
760
18%
1692
December11th to 20thNight
23%
760
20%
3173
8%
759
39%
759
17%
1873
December21st to endNight
29%
824
14%
4788
11%
817
45%
817
13%
2796

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
14%6%25%5%345%5%8%43%
78299
Night
15%6%35%5%3445%7%43%
80754
TransparencyDay
39%6%13%24%16%3
78006
Night
41%5%11%23%16%3
80581
SeeingDay
17%6%20%31%22%5%
14084
Night
18%8%25%30%16%3
23495

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%7%25%424446%48%
2517
11th to 20thDay
15%7%36%5%3445%5%42%
2566
21st to endDay
19%10%36%5%335%45%37%
3124
February1st to 10thDay
15%8%26%5%2447%8%39%
1730
11th to 20thDay
18%6%35%33445%6%43%
1788
21st to endDay
18%8%35%5%2445%6%39%
1480
March1st to 10thDay
14%6%24433446%49%
1797
11th to 20thDay
17%5%35%43445%8%43%
1938
21st to endDay
18%6%35%5%35%5%46%40%
2330
April1st to 10thDay
15%7%3443445%6%44%
2160
11th to 20thDay
13%6%2343445%7%46%
2134
21st to endDay
16%5%25%5%35%5%6%8%40%
2160
May1st to 10thDay
17%6%25%5%45%5%6%8%38%
2286
11th to 20thDay
17%7%25%5%3445%8%40%
2427
21st to endDay
12%7%245%346%6%9%42%
2725
June1st to 10thDay
13%6%245%35%6%8%10%39%
2520
11th to 20thDay
11%5%25%5%46%5%7%9%41%
2520
21st to endDay
9%3245%35%7%9%10%44%
2520
July1st to 10thDay
9%5%25%5%45%6%6%11%43%
2520
11th to 20thDay
5%4245%35%7%8%11%46%
2520
21st to endDay
9%435%6%45%6%8%11%40%
2718
August1st to 10thDay
9%5%15%5%35%5%7%11%44%
2270
11th to 20thDay
11%425%6%346%6%9%44%
2126
21st to endDay
10%5%35%5%35%5%7%9%43%
2376
September1st to 10thDay
16%42343445%8%47%
2160
11th to 20thDay
12%425%5%3445%8%48%
2101
21st to endDay
18%6%35%5%35%5%47%39%
1980
October1st to 10thDay
18%6%245%34447%44%
1859
11th to 20thDay
16%43443345%5%50%
1800
21st to endDay
16%6%25%425%446%46%
1896
November1st to 10thDay
15%5%25%3235%47%50%
1671
11th to 20thDay
14%425%5%3445%7%47%
1710
21st to endDay
15%5%145%34437%48%
1672
December1st to 10thDay
17%6%35%426%5%5%7%41%
1520
11th to 20thDay
16%7%34424347%46%
1906
21st to endDay
15%7%35%5%235%5%9%41%
2772
January1st to 10thNight
16%6%2443445%6%47%
4429
11th to 20thNight
20%8%35%423345%45%
4379
21st to endNight
19%9%36%5%33446%38%
4532
February1st to 10thNight
18%7%25%4245%46%43%
2448
11th to 20thNight
19%7%25%43445%5%41%
2153
21st to endNight
17%8%2442445%6%44%
1776
March1st to 10thNight
16%5%24423347%50%
2150
11th to 20thNight
17%7%35%5%24446%43%
2019
21st to endNight
18%7%36%5%3443442%
2024
April1st to 10thNight
17%8%36%42445%6%41%
1800
11th to 20thNight
14%6%26%6%25%347%46%
1775
21st to endNight
19%6%35%435%45%7%40%
1800
May1st to 10thNight
17%9%37%5%45%45%8%34%
1672
11th to 20thNight
18%6%36%6%35%5%46%37%
1481
21st to endNight
16%9%36%5%35%45%8%36%
1550
June1st to 10thNight
16%7%26%5%35%46%7%40%
1440
11th to 20thNight
11%5%36%6%45%5%6%9%40%
1440
21st to endNight
8%425%5%46%6%7%10%42%
1440
July1st to 10thNight
9%6%36%6%47%46%10%40%
1440
11th to 20thNight
6%5%36%6%45%6%7%10%43%
1440
21st to endNight
8%436%6%36%7%6%9%41%
1596
August1st to 10thNight
8%5%26%7%46%6%7%10%40%
1651
11th to 20thNight
10%5%26%436%6%6%9%42%
1774
21st to endNight
10%5%25%5%346%7%8%44%
1980
September1st to 10thNight
15%8%245%3445%8%43%
1800
11th to 20thNight
12%5%244345%5%9%48%
1858
21st to endNight
20%7%36%42445%6%39%
1980
October1st to 10thNight
19%5%245%33446%42%
2098
11th to 20thNight
17%5%2432335%5%50%
2160
21st to endNight
16%6%25%43445%6%46%
2457
November1st to 10thNight
13%5%3442435%6%51%
2407
11th to 20thNight
15%6%25%5%23336%48%
2470
21st to endNight
13%5%245%3445%7%48%
2503
December1st to 10thNight
18%8%35%43445%6%40%
2660
11th to 20thNight
18%5%245%3345%7%43%
3288
21st to endNight
14%7%36%6%35%45%7%40%
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
39%310%28%16%3
2518
11th to 20thDay
44%412%22%14%5%
2566
21st to endDay
49%6%10%21%12%3
3124
February1st to 10thDay
42%6%13%25%13%1
1730
11th to 20thDay
43%49%25%15%4
1797
21st to endDay
46%49%22%14%5%
1480
March1st to 10thDay
37%5%11%28%17%3
1800
11th to 20thDay
40%5%12%22%18%4
1938
21st to endDay
45%5%9%21%16%4
2330
April1st to 10thDay
41%5%12%19%17%6%
2160
11th to 20thDay
37%6%13%23%17%4
2134
21st to endDay
41%7%11%19%18%5%
2160
May1st to 10thDay
43%6%12%22%13%3
2286
11th to 20thDay
43%5%14%22%13%2
2431
21st to endDay
40%6%16%25%12%1
2725
June1st to 10thDay
37%10%15%23%14%2
2520
11th to 20thDay
38%9%15%25%11%2
2520
21st to endDay
31%8%16%26%18%1
2520
July1st to 10thDay
34%9%17%23%15%1
2450
11th to 20thDay
29%9%16%31%13%2
2445
21st to endDay
34%9%15%26%15%1
2566
August1st to 10thDay
33%8%16%28%14%1
2257
11th to 20thDay
36%8%17%24%14%1
2126
21st to endDay
35%9%14%24%16%3
2376
September1st to 10thDay
36%6%17%22%17%2
2160
11th to 20thDay
35%5%10%24%23%3
2101
21st to endDay
45%5%10%19%18%3
1980
October1st to 10thDay
41%5%12%24%16%2
1859
11th to 20thDay
37%410%25%22%2
1800
21st to endDay
41%410%23%20%2
1896
November1st to 10thDay
36%412%28%16%4
1671
11th to 20thDay
39%310%22%23%3
1710
21st to endDay
38%311%30%15%3
1672
December1st to 10thDay
43%5%15%21%14%2
1520
11th to 20thDay
41%410%28%15%3
1906
21st to endDay
40%7%14%24%14%1
2772
January1st to 10thNight
38%310%29%16%4
4429
11th to 20thNight
44%311%25%15%2
4379
21st to endNight
49%48%25%13%2
4532
February1st to 10thNight
43%313%24%14%2
2448
11th to 20thNight
45%49%19%18%5%
2155
21st to endNight
42%49%22%18%4
1776
March1st to 10thNight
36%412%24%20%4
2160
11th to 20thNight
43%5%10%20%17%5%
2020
21st to endNight
47%39%18%18%6%
2024
April1st to 10thNight
44%48%20%18%5%
1800
11th to 20thNight
41%410%20%20%5%
1775
21st to endNight
44%6%9%18%18%5%
1800
May1st to 10thNight
49%6%9%18%16%2
1672
11th to 20thNight
49%5%10%16%18%2
1482
21st to endNight
47%7%14%20%12%1
1551
June1st to 10thNight
43%7%10%21%18%1
1440
11th to 20thNight
40%9%11%25%14%2
1440
21st to endNight
37%6%13%26%15%3
1440
July1st to 10thNight
40%8%16%23%11%2
1400
11th to 20thNight
34%9%17%26%12%2
1392
21st to endNight
37%8%13%25%17%1
1507
August1st to 10thNight
37%9%17%22%14%1
1640
11th to 20thNight
36%9%15%24%15%1
1774
21st to endNight
36%8%14%21%17%3
1980
September1st to 10thNight
41%5%12%22%16%4
1800
11th to 20thNight
33%6%12%24%22%3
1858
21st to endNight
47%6%6%20%19%2
1980
October1st to 10thNight
44%5%11%20%19%2
2098
11th to 20thNight
37%410%28%18%3
2160
21st to endNight
41%410%25%18%3
2457
November1st to 10thNight
35%411%26%19%5%
2407
11th to 20thNight
40%410%21%20%5%
2470
21st to endNight
36%412%26%19%2
2503
December1st to 10thNight
45%412%22%13%2
2660
11th to 20thNight
41%412%21%19%3
3288
21st to endNight
43%5%16%25%11%1
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
15%14%28%33%8%2
180
11th to 20thDay
16%14%34%28%7%1
195
21st to endDay
21%7%33%26%13%1
297
February1st to 10thDay
20%9%29%32%9%1
290
11th to 20thDay
25%11%36%23%5%
432
21st to endDay
25%10%33%25%6%
346
March1st to 10thDay
15%8%38%31%7%
420
11th to 20thDay
18%8%33%31%7%2
420
21st to endDay
19%8%31%31%10%1
462
April1st to 10thDay
18%9%31%31%10%1
420
11th to 20thDay
14%8%26%39%11%1
412
21st to endDay
22%6%25%35%12%1
420
May1st to 10thDay
23%423%35%13%2
423
11th to 20thDay
22%318%37%17%2
447
21st to endDay
19%212%30%30%7%
485
June1st to 10thDay
18%112%34%29%5%
450
11th to 20thDay
14%214%37%27%5%
450
21st to endDay
10%210%41%34%4
450
July1st to 10thDay
11%17%31%36%13%
445
11th to 20thDay
7%15%31%45%10%
444
21st to endDay
10%28%38%36%6%
488
August1st to 10thDay
10%27%34%38%8%
446
11th to 20thDay
11%28%29%39%11%
439
21st to endDay
12%28%33%33%13%
495
September1st to 10thDay
18%213%23%32%12%
450
11th to 20thDay
15%312%28%33%9%
450
21st to endDay
23%415%32%22%3
450
October1st to 10thDay
24%414%26%25%7%
450
11th to 20thDay
18%5%18%29%24%6%
450
21st to endDay
18%8%26%28%15%5%
453
November1st to 10thDay
17%6%24%30%21%3
365
11th to 20thDay
12%12%34%26%15%1
370
21st to endDay
15%14%26%27%16%2
332
December1st to 10thDay
23%11%29%24%13%1
180
11th to 20thDay
21%9%30%28%12%
180
21st to endDay
20%11%28%25%15%2
198
January1st to 10thNight
20%17%34%21%7%
760
11th to 20thNight
21%15%32%26%6%
760
21st to endNight
19%14%37%27%3
836
February1st to 10thNight
21%11%35%28%5%
760
11th to 20thNight
24%12%41%21%2
722
21st to endNight
20%12%36%28%3
592
March1st to 10thNight
18%10%37%29%5%
720
11th to 20thNight
21%9%32%29%7%2
720
21st to endNight
22%6%32%31%8%2
792
April1st to 10thNight
21%8%34%28%8%1
720
11th to 20thNight
16%5%27%39%13%
711
21st to endNight
21%428%34%11%1
720
May1st to 10thNight
20%5%24%35%13%3
592
11th to 20thNight
20%324%35%16%2
420
21st to endNight
19%212%31%29%6%
389
June1st to 10thNight
22%212%36%26%3
360
11th to 20thNight
14%114%39%31%2
360
21st to endNight
9%210%45%30%4
360
July1st to 10thNight
12%110%40%31%6%
350
11th to 20thNight
7%27%34%44%6%
348
21st to endNight
9%29%38%37%5%
416
August1st to 10thNight
10%28%35%39%6%
577
11th to 20thNight
12%111%34%33%8%
710
21st to endNight
12%29%33%37%8%
792
September1st to 10thNight
18%212%29%29%10%
720
11th to 20thNight
14%213%31%31%9%
720
21st to endNight
24%318%28%24%3
720
October1st to 10thNight
23%418%27%21%8%
720
11th to 20thNight
20%7%21%32%18%1
720
21st to endNight
20%8%30%27%13%2
792
November1st to 10thNight
16%10%25%30%15%4
740
11th to 20thNight
18%12%30%28%12%1
760
21st to endNight
15%13%31%29%10%2
760
December1st to 10thNight
21%13%34%21%9%2
760
11th to 20thNight
19%12%37%25%6%1
760
21st to endNight
19%12%33%30%6%
836
Page generated at 2024-02-12 06:35:33. Version ac07

Copyright 2024 Attilla Danko


Ocean City Clear Sky Chart |Charts Home