Chesapeake Beach Veterans Memorial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chesapeake Beach Veterans Memorial Park clear sky chart from 2005-11-06 to 2024-03-01.

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
36%
23667
20%
80149
11%
23563
47%
23563
22%
49536

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%
755
23%
4319
8%
737
39%
737
12%
2379
January11th to 20thNight
21%
759
26%
3957
8%
740
38%
740
13%
2220
January21st to endNight
20%
832
16%
4449
10%
814
39%
814
12%
2702
February1st to 10thNight
24%
760
19%
2470
9%
760
38%
760
20%
1562
February11th to 20thNight
13%
742
20%
2307
4%
740
32%
740
17%
1476
February21st to endNight
18%
628
24%
1884
7%
628
38%
628
20%
1201
March1st to 10thNight
23%
723
24%
2064
8%
723
40%
723
25%
1274
March11th to 20thNight
23%
720
20%
1980
7%
720
36%
720
23%
1303
March21st to endNight
21%
792
21%
2116
6%
792
33%
792
24%
1410
April1st to 10thNight
21%
720
19%
1800
3%
720
32%
720
24%
1219
April11th to 20thNight
33%
711
21%
1775
7%
711
40%
711
31%
1149
April21st to endNight
32%
720
20%
1800
7%
720
38%
720
27%
1209
May1st to 10thNight
34%
659
17%
1739
7%
659
40%
659
26%
1177
May11th to 20thNight
38%
382
17%
1443
11%
382
47%
382
19%
910
May21st to endNight
51%
388
16%
1551
17%
388
55%
388
21%
921
June1st to 10thNight
52%
360
19%
1440
18%
360
60%
360
23%
853
June11th to 20thNight
53%
360
17%
1440
17%
360
59%
360
21%
869
June21st to endNight
55%
360
16%
1440
17%
360
60%
360
24%
824
July1st to 10thNight
60%
350
15%
1400
17%
350
64%
350
21%
860
July11th to 20thNight
68%
374
17%
1418
20%
374
68%
374
27%
804
July21st to endNight
59%
591
18%
1672
12%
558
65%
558
30%
1041
August1st to 10thNight
65%
537
16%
1600
12%
534
66%
534
28%
1029
August11th to 20thNight
57%
653
15%
1717
9%
653
59%
653
26%
1203
August21st to endNight
60%
792
18%
1980
10%
792
62%
792
31%
1322
September1st to 10thNight
55%
720
22%
1800
12%
720
59%
720
33%
1199
September11th to 20thNight
61%
720
28%
1800
19%
720
65%
720
38%
1134
September21st to endNight
42%
720
19%
2038
13%
720
48%
720
23%
1397
October1st to 10thNight
45%
720
19%
2160
15%
720
51%
720
25%
1390
October11th to 20thNight
39%
720
26%
2160
17%
720
51%
720
27%
1311
October21st to endNight
34%
792
27%
2376
15%
792
50%
792
27%
1451
November1st to 10thNight
35%
740
26%
2353
14%
740
50%
740
29%
1371
November11th to 20thNight
29%
760
25%
2470
13%
760
45%
760
24%
1476
November21st to endNight
32%
760
24%
2617
13%
760
48%
760
25%
1459
December1st to 10thNight
24%
760
20%
2660
6%
760
42%
760
17%
1656
December11th to 20thNight
23%
760
21%
3166
8%
759
40%
759
17%
1882
December21st to endNight
27%
827
14%
4788
10%
817
42%
817
11%
2893

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%5%24435%5%6%8%44%
78513
Night
15%6%25%5%3445%7%44%
80901
TransparencyDay
38%8%13%24%16%3
78223
Night
39%7%11%23%17%3
80710
SeeingDay
17%12%28%26%13%4
14068
Night
17%13%29%27%12%1
23688

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
16%5%25%33435%7%49%
2526
11th to 20thDay
14%9%36%5%34445%41%
2840
21st to endDay
17%7%26%5%25%45%7%39%
3124
February1st to 10thDay
15%6%35%5%445%6%7%40%
1710
11th to 20thDay
19%6%2342345%7%44%
1761
21st to endDay
17%8%25%5%345%5%6%39%
1570
March1st to 10thDay
13%6%24435%35%7%50%
1900
11th to 20thDay
17%5%25%5%3445%7%43%
1980
21st to endDay
17%7%25%6%35%45%6%40%
2240
April1st to 10thDay
12%6%235%3446%9%44%
2160
11th to 20thDay
13%414435%45%7%49%
2134
21st to endDay
17%5%34435%5%5%7%43%
2160
May1st to 10thDay
15%5%245%245%6%9%42%
2236
11th to 20thDay
17%5%245%345%6%9%39%
2450
21st to endDay
14%5%145%35%5%6%9%43%
2725
June1st to 10thDay
10%324436%5%7%10%45%
2520
11th to 20thDay
10%425%446%5%7%10%44%
2520
21st to endDay
9%214436%7%7%12%45%
2520
July1st to 10thDay
8%5%26%5%36%5%6%10%44%
2520
11th to 20thDay
43245%46%7%7%12%47%
2491
21st to endDay
8%5%246%36%7%9%11%39%
2547
August1st to 10thDay
9%5%25%5%45%7%7%11%40%
2327
11th to 20thDay
10%5%35%6%35%5%7%9%43%
2165
21st to endDay
10%5%25%5%35%6%7%10%44%
2376
September1st to 10thDay
14%4245%345%5%8%47%
2160
11th to 20thDay
12%6%2443335%8%50%
2160
21st to endDay
18%7%35%43446%7%40%
1918
October1st to 10thDay
18%42342445%7%48%
1800
11th to 20thDay
19%32333335%7%50%
1800
21st to endDay
14%5%25%43445%7%48%
1980
November1st to 10thDay
13%423424447%53%
1723
11th to 20thDay
14%5%2332445%7%50%
1710
21st to endDay
14%6%24424447%50%
1558
December1st to 10thDay
16%5%25%5%25%5%5%6%44%
1520
11th to 20thDay
15%7%34323446%47%
1910
21st to endDay
16%7%26%435%5%6%7%39%
2772
January1st to 10thNight
15%7%35%434447%45%
4415
11th to 20thNight
18%7%35%423345%46%
4120
21st to endNight
18%9%36%423445%42%
4532
February1st to 10thNight
16%6%245%345%47%43%
2470
11th to 20thNight
19%6%35%423346%44%
2305
21st to endNight
18%7%25%32345%7%44%
1884
March1st to 10thNight
13%5%25%5%33347%50%
2064
11th to 20thNight
18%6%24435%45%7%44%
1980
21st to endNight
16%7%36%6%34447%42%
2116
April1st to 10thNight
16%7%245%345%6%6%42%
1800
11th to 20thNight
13%425%5%3445%7%48%
1775
21st to endNight
19%5%25%42445%8%43%
1800
May1st to 10thNight
15%6%36%435%6%6%9%39%
1739
11th to 20thNight
16%6%35%435%6%7%9%38%
1443
21st to endNight
15%5%246%245%6%10%41%
1550
June1st to 10thNight
12%435%5%345%6%10%44%
1440
11th to 20thNight
12%6%26%5%45%5%5%11%40%
1440
21st to endNight
9%5%25%5%35%6%7%12%40%
1440
July1st to 10thNight
9%6%25%6%36%6%8%10%40%
1440
11th to 20thNight
6%425%6%36%5%7%10%45%
1466
21st to endNight
8%425%6%46%7%7%9%41%
1771
August1st to 10thNight
8%436%6%46%6%7%11%41%
1611
11th to 20thNight
10%5%36%6%5%6%6%6%9%38%
1717
21st to endNight
11%6%26%435%7%6%8%43%
1980
September1st to 10thNight
15%435%5%2446%7%45%
1800
11th to 20thNight
10%5%245%3445%8%49%
1800
21st to endNight
19%7%25%5%2446%7%39%
2038
October1st to 10thNight
19%5%25%3245%46%45%
2160
11th to 20thNight
17%424423337%50%
2160
21st to endNight
16%425%43445%6%48%
2376
November1st to 10thNight
13%5%25%32435%5%53%
2353
11th to 20thNight
16%6%24424346%49%
2470
21st to endNight
13%4244245%6%6%50%
2617
December1st to 10thNight
17%6%35%43445%7%41%
2660
11th to 20thNight
16%5%25%43445%6%44%
3285
21st to endNight
16%6%25%5%35%6%6%7%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
36%5%8%32%16%4
2527
11th to 20thDay
43%5%10%21%16%5%
2840
21st to endDay
45%6%13%22%11%2
3124
February1st to 10thDay
43%6%12%25%12%2
1710
11th to 20thDay
40%5%10%25%17%3
1770
21st to endDay
45%5%13%17%15%4
1570
March1st to 10thDay
36%5%11%24%21%3
1900
11th to 20thDay
41%7%10%19%17%6%
1980
21st to endDay
45%6%10%19%17%3
2240
April1st to 10thDay
35%8%11%21%18%6%
2160
11th to 20thDay
35%6%11%21%20%7%
2134
21st to endDay
41%6%11%21%16%5%
2160
May1st to 10thDay
39%8%15%21%15%3
2236
11th to 20thDay
41%9%14%21%14%2
2454
21st to endDay
37%9%15%26%11%2
2725
June1st to 10thDay
34%10%15%26%14%1
2520
11th to 20thDay
34%12%14%22%16%2
2520
21st to endDay
32%10%17%24%16%1
2520
July1st to 10thDay
36%11%14%22%15%3
2450
11th to 20thDay
27%12%18%27%14%3
2416
21st to endDay
36%11%16%20%17%1
2405
August1st to 10thDay
37%10%17%24%11%1
2314
11th to 20thDay
38%10%16%22%13%1
2165
21st to endDay
35%9%15%23%13%4
2376
September1st to 10thDay
36%8%14%21%17%4
2160
11th to 20thDay
33%6%12%26%19%3
2160
21st to endDay
44%7%9%21%17%3
1918
October1st to 10thDay
38%6%11%25%17%3
1800
11th to 20thDay
35%410%27%21%3
1800
21st to endDay
37%5%8%26%20%4
1980
November1st to 10thDay
31%6%11%27%21%4
1723
11th to 20thDay
35%5%11%24%21%5%
1710
21st to endDay
37%49%28%19%3
1558
December1st to 10thDay
41%6%14%25%11%3
1520
11th to 20thDay
38%5%9%32%12%3
1906
21st to endDay
41%9%12%25%12%1
2772
January1st to 10thNight
39%6%9%25%18%4
4415
11th to 20thNight
41%49%25%18%3
4120
21st to endNight
45%5%8%25%16%1
4532
February1st to 10thNight
41%5%11%24%16%2
2470
11th to 20thNight
42%5%8%21%19%5%
2307
21st to endNight
41%5%11%22%17%5%
1884
March1st to 10thNight
36%410%26%19%3
2064
11th to 20thNight
41%6%10%22%18%3
1980
21st to endNight
42%5%11%20%16%6%
2116
April1st to 10thNight
41%6%10%20%20%4
1800
11th to 20thNight
36%6%12%20%21%6%
1775
21st to endNight
40%6%11%23%15%5%
1800
May1st to 10thNight
40%8%13%21%14%4
1739
11th to 20thNight
41%9%15%17%16%2
1444
21st to endNight
37%9%17%22%13%1
1551
June1st to 10thNight
35%10%12%25%17%1
1440
11th to 20thNight
38%9%14%22%13%3
1440
21st to endNight
35%9%16%20%19%2
1440
July1st to 10thNight
36%12%17%19%13%3
1400
11th to 20thNight
30%11%17%26%14%2
1418
21st to endNight
33%10%15%27%14%
1672
August1st to 10thNight
35%11%17%24%13%1
1600
11th to 20thNight
42%10%15%20%12%1
1717
21st to endNight
38%8%15%22%15%3
1980
September1st to 10thNight
37%7%13%22%16%6%
1800
11th to 20thNight
32%7%11%25%22%4
1800
21st to endNight
43%8%10%19%17%3
2038
October1st to 10thNight
41%6%10%22%18%4
2160
11th to 20thNight
37%5%9%26%21%4
2160
21st to endNight
37%5%9%25%21%4
2376
November1st to 10thNight
34%5%10%25%20%6%
2353
11th to 20thNight
37%410%21%21%6%
2470
21st to endNight
32%5%12%25%21%4
2617
December1st to 10thNight
41%6%12%24%14%3
2660
11th to 20thNight
40%6%10%23%18%4
3288
21st to endNight
41%9%14%24%10%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
24%21%35%15%41
184
11th to 20thDay
23%28%32%16%1
270
21st to endDay
21%22%40%15%11
297
February1st to 10thDay
19%23%41%12%4
270
11th to 20thDay
27%24%37%11%1
368
21st to endDay
26%23%34%14%2
382
March1st to 10thDay
18%25%38%17%2
420
11th to 20thDay
21%22%35%15%5%1
420
21st to endDay
21%21%35%19%31
462
April1st to 10thDay
17%20%40%17%5%
420
11th to 20thDay
13%18%34%25%7%2
412
21st to endDay
21%16%35%21%6%
420
May1st to 10thDay
21%16%33%21%10%
423
11th to 20thDay
23%9%34%24%9%1
447
21st to endDay
19%5%22%31%19%4
485
June1st to 10thDay
12%5%29%30%21%3
450
11th to 20thDay
12%8%28%32%17%5%
450
21st to endDay
9%5%27%38%16%4
450
July1st to 10thDay
11%319%33%27%7%
445
11th to 20thDay
4113%45%29%8%
444
21st to endDay
11%319%38%24%6%
488
August1st to 10thDay
13%419%33%24%7%
446
11th to 20thDay
12%215%38%23%9%
439
21st to endDay
9%420%33%23%10%
495
September1st to 10thDay
16%418%29%20%13%
450
11th to 20thDay
14%6%20%30%22%8%
450
21st to endDay
24%9%24%28%12%3
450
October1st to 10thDay
20%8%23%26%19%4
450
11th to 20thDay
18%13%25%28%14%1
450
21st to endDay
15%13%35%26%7%3
495
November1st to 10thDay
17%13%30%25%12%4
390
11th to 20thDay
18%17%35%20%9%1
370
21st to endDay
19%21%30%20%10%
218
December1st to 10thDay
19%19%42%14%41
180
11th to 20thDay
24%19%31%20%6%
180
21st to endDay
23%16%32%25%5%
198
January1st to 10thNight
18%24%36%17%4
760
11th to 20thNight
22%17%34%21%5%
760
21st to endNight
19%21%37%21%2
836
February1st to 10thNight
18%18%37%24%3
760
11th to 20thNight
23%25%36%14%1
743
21st to endNight
22%21%36%18%2
628
March1st to 10thNight
17%19%38%22%3
723
11th to 20thNight
22%16%36%18%6%1
720
21st to endNight
19%15%41%20%5%
792
April1st to 10thNight
19%21%36%20%4
720
11th to 20thNight
15%12%36%30%7%
711
21st to endNight
23%11%30%27%9%
720
May1st to 10thNight
19%8%35%27%10%1
659
11th to 20thNight
17%8%31%34%10%
382
21st to endNight
14%423%37%20%2
389
June1st to 10thNight
13%325%38%20%2
360
11th to 20thNight
12%6%18%46%17%1
360
21st to endNight
10%223%47%16%2
360
July1st to 10thNight
9%418%38%28%3
350
11th to 20thNight
6%112%45%32%3
374
21st to endNight
8%220%39%27%4
591
August1st to 10thNight
9%214%45%28%3
537
11th to 20thNight
11%417%38%28%2
653
21st to endNight
12%317%32%30%6%
792
September1st to 10thNight
16%317%33%26%5%
720
11th to 20thNight
11%416%37%27%4
720
21st to endNight
22%6%23%29%18%1
720
October1st to 10thNight
20%8%20%30%17%5%
720
11th to 20thNight
18%12%26%28%15%1
720
21st to endNight
19%13%30%24%13%1
792
November1st to 10thNight
15%12%34%25%12%2
740
11th to 20thNight
18%19%31%23%8%1
760
21st to endNight
16%18%31%25%9%1
760
December1st to 10thNight
20%20%31%19%8%1
760
11th to 20thNight
18%16%39%21%6%
760
21st to endNight
18%18%32%28%3
836
Page generated at 2024-02-27 06:30:15. Version ac07

Copyright © 2024 Attilla Danko.


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