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Fort Meade Recreation Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Fort Meade Recreation Area clear sky chart from 2005-11-06 to 2024-01-16.

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
42%
24867
23%
74462
13%
24815
51%
24815
32%
43174

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
37%
949
25%
2647
12%
946
48%
946
29%
1573
January11th to 20thNight
32%
926
22%
2591
10%
926
43%
926
27%
1570
January21st to endNight
27%
990
21%
2772
7%
990
40%
990
22%
1775
February1st to 10thNight
31%
752
17%
2372
9%
752
40%
752
21%
1523
February11th to 20thNight
33%
700
21%
2144
12%
700
42%
700
25%
1304
February21st to endNight
35%
592
22%
1776
9%
592
46%
592
28%
1089
March1st to 10thNight
37%
720
22%
2160
10%
720
48%
720
30%
1293
March11th to 20thNight
39%
712
23%
2113
15%
712
47%
712
31%
1268
March21st to endNight
38%
594
18%
1980
13%
594
46%
594
22%
1247
April1st to 10thNight
39%
540
17%
1800
12%
540
48%
540
24%
1104
April11th to 20thNight
30%
533
19%
1777
11%
533
43%
533
24%
1089
April21st to endNight
39%
540
18%
1666
13%
540
48%
540
27%
1041
May1st to 10thNight
45%
540
19%
1546
13%
540
51%
540
33%
941
May11th to 20thNight
46%
531
19%
1418
11%
531
50%
531
32%
902
May21st to endNight
35%
583
16%
1552
7%
582
40%
582
29%
1022
June1st to 10thNight
51%
540
16%
1440
8%
540
55%
540
37%
870
June11th to 20thNight
41%
540
14%
1440
6%
540
45%
540
35%
896
June21st to endNight
57%
540
17%
1440
9%
540
60%
540
44%
811
July1st to 10thNight
62%
525
16%
1400
9%
525
65%
525
46%
789
July11th to 20thNight
61%
522
23%
1392
13%
522
66%
522
51%
757
July21st to endNight
68%
591
27%
1488
19%
558
71%
558
54%
776
August1st to 10thNight
64%
537
26%
1424
19%
534
68%
534
43%
824
August11th to 20thNight
64%
534
28%
1662
23%
534
71%
534
47%
815
August21st to endNight
65%
594
30%
1980
31%
594
72%
594
48%
914
September1st to 10thNight
64%
540
29%
1800
28%
540
73%
540
44%
882
September11th to 20thNight
59%
540
31%
1872
28%
540
70%
540
41%
924
September21st to endNight
50%
540
31%
1980
27%
540
59%
540
36%
971
October1st to 10thNight
46%
636
26%
2076
19%
636
54%
636
30%
1177
October11th to 20thNight
41%
735
29%
2175
13%
735
53%
735
34%
1247
October21st to endNight
35%
990
26%
2574
9%
990
45%
990
35%
1523
November1st to 10thNight
39%
925
25%
2405
12%
925
46%
925
35%
1468
November11th to 20thNight
37%
950
32%
2484
13%
950
50%
950
35%
1468
November21st to endNight
35%
950
28%
2660
11%
950
49%
950
35%
1492
December1st to 10thNight
31%
950
24%
2660
9%
950
44%
950
29%
1599
December11th to 20thNight
35%
948
27%
3082
11%
948
46%
948
31%
1635
December21st to endNight
31%
1038
15%
4714
7%
1026
44%
1026
17%
2595

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
6%5%25%435%5%6%9%50%
74832
Night
6%5%25%5%35%5%6%8%51%
74993
TransparencyDay
30%7%15%28%17%4
74536
Night
30%7%13%28%18%4
74811
SeeingDay
12%12%30%29%14%3
14761
Night
10%13%30%34%12%1
24882

By Month

Percentage Cloud Cover SW (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
25%25%6%35%6%6%11%50%
1518
11th to 20thDay
2446%6%36%6%6%9%48%
1480
21st to endDay
25%38%6%37%7%7%8%44%
1584
February1st to 10thDay
39%47%6%5%6%6%7%8%39%
1605
11th to 20thDay
46%38%7%36%5%6%7%44%
1702
21st to endDay
36%47%7%45%5%6%10%43%
1480
March1st to 10thDay
36%37%5%45%6%7%8%47%
1800
11th to 20thDay
6%5%25%43445%9%52%
1844
21st to endDay
8%11%36%6%37%5%6%9%37%
2376
April1st to 10thDay
10%9%35%325%5%6%9%43%
2160
11th to 20thDay
10%8%36%6%45%6%5%9%37%
2131
21st to endDay
12%7%25%5%45%5%7%8%39%
2294
May1st to 10thDay
11%6%36%6%36%6%6%8%40%
2412
11th to 20thDay
14%7%35%435%5%6%9%39%
2478
21st to endDay
16%6%245%346%7%10%36%
2724
June1st to 10thDay
7%424435%7%7%10%47%
2520
11th to 20thDay
7%423435%6%7%10%48%
2520
21st to endDay
3423325%46%8%61%
2520
July1st to 10thDay
4213435%6%7%10%54%
2520
11th to 20thDay
32122245%6%8%64%
2520
21st to endDay
421332447%9%59%
2742
August1st to 10thDay
4225%445%6%7%9%53%
2507
11th to 20thDay
43133245%6%9%60%
2235
21st to endDay
42133245%6%7%64%
2376
September1st to 10thDay
6%42333245%7%61%
2160
11th to 20thDay
7%41232345%6%63%
2088
21st to endDay
9%413333348%59%
1980
October1st to 10thDay
10%6%25%425%447%54%
1882
11th to 20thDay
10%5%243235%5%6%56%
1766
21st to endDay
5%5%343245%6%9%53%
1782
November1st to 10thDay
45%24325%5%6%8%57%
1673
11th to 20thDay
35%25%4346%6%8%55%
1693
21st to endDay
35%35%5%35%46%9%53%
1520
December1st to 10thDay
15%26%6%35%7%7%10%48%
1520
11th to 20thDay
23245%35%5%7%11%55%
1926
21st to endDay
6%7%36%5%35%448%49%
2794
January1st to 10thNight
2425%5%46%7%8%8%49%
2647
11th to 20thNight
2436%6%36%6%6%10%48%
2591
21st to endNight
26%36%7%5%6%7%6%9%44%
2772
February1st to 10thNight
48%37%6%36%6%7%8%41%
2372
11th to 20thNight
27%46%6%45%5%8%9%44%
2144
21st to endNight
47%36%6%35%6%6%8%46%
1776
March1st to 10thNight
47%26%5%345%7%9%48%
2160
11th to 20thNight
7%5%35%5%35%6%6%9%47%
2113
21st to endNight
9%8%35%5%35%6%6%10%39%
1980
April1st to 10thNight
10%7%35%5%35%5%5%8%44%
1800
11th to 20thNight
11%7%45%5%35%5%5%7%44%
1777
21st to endNight
11%7%35%435%46%7%45%
1666
May1st to 10thNight
9%6%25%5%345%5%9%49%
1546
11th to 20thNight
12%7%2444346%8%47%
1417
21st to endNight
16%4245%2447%10%42%
1552
June1st to 10thNight
8%5%2342446%10%51%
1440
11th to 20thNight
8%5%135%35%48%10%48%
1440
21st to endNight
6%3243345%6%8%57%
1440
July1st to 10thNight
42235%25%5%8%10%54%
1440
11th to 20thNight
42133245%5%8%62%
1440
21st to endNight
22124345%7%9%60%
1576
August1st to 10thNight
4414435%6%7%9%53%
1432
11th to 20thNight
43134235%5%8%62%
1662
21st to endNight
321342345%7%65%
1980
September1st to 10thNight
5%31343345%7%62%
1800
11th to 20thNight
6%32331445%7%60%
1872
21st to endNight
10%313324346%60%
1980
October1st to 10thNight
10%7%24334447%51%
2076
11th to 20thNight
8%4244236%5%6%56%
2175
21st to endNight
7%6%2442445%8%53%
2574
November1st to 10thNight
5%5%25%5%35%5%6%8%51%
2405
11th to 20thNight
45%25%5%345%7%8%53%
2484
21st to endNight
3434435%47%8%55%
2660
December1st to 10thNight
25%36%6%35%5%7%9%49%
2660
11th to 20thNight
23245%35%5%6%11%55%
3271
21st to endNight
6%9%35%4345%5%7%48%
4873

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
29%8%18%29%14%2
1519
11th to 20thDay
30%9%17%30%11%4
1480
21st to endDay
34%9%17%24%14%2
1584
February1st to 10thDay
40%9%14%22%14%2
1605
11th to 20thDay
38%8%16%21%14%4
1712
21st to endDay
36%6%16%25%12%5%
1480
March1st to 10thDay
35%7%15%28%14%2
1800
11th to 20thDay
29%5%15%33%16%2
1844
21st to endDay
43%8%14%25%9%1
2376
April1st to 10thDay
38%6%19%24%11%3
2160
11th to 20thDay
41%7%15%24%10%2
2134
21st to endDay
40%7%18%26%9%1
2294
May1st to 10thDay
40%6%15%28%10%
2412
11th to 20thDay
41%6%17%25%10%
2482
21st to endDay
41%8%19%24%7%2
2724
June1st to 10thDay
30%9%20%27%13%2
2520
11th to 20thDay
29%6%20%27%15%3
2520
21st to endDay
20%6%16%31%23%5%
2520
July1st to 10thDay
22%7%16%29%21%4
2451
11th to 20thDay
17%412%29%25%13%
2445
21st to endDay
19%6%11%28%26%10%
2590
August1st to 10thDay
24%7%14%29%18%8%
2491
11th to 20thDay
20%6%11%34%23%6%
2235
21st to endDay
19%5%12%25%30%9%
2376
September1st to 10thDay
23%49%27%27%10%
2160
11th to 20thDay
23%5%10%30%24%7%
2088
21st to endDay
25%410%34%25%2
1980
October1st to 10thDay
32%412%27%21%4
1882
11th to 20thDay
28%5%12%29%20%5%
1766
21st to endDay
27%7%15%29%17%5%
1782
November1st to 10thDay
24%6%14%27%23%5%
1673
11th to 20thDay
26%5%12%30%22%4
1693
21st to endDay
28%6%13%31%18%3
1520
December1st to 10thDay
29%9%15%28%17%2
1520
11th to 20thDay
23%8%18%38%12%2
1924
21st to endDay
34%5%9%30%19%2
2794
January1st to 10thNight
29%8%15%29%16%3
2647
11th to 20thNight
30%8%18%26%15%3
2591
21st to endNight
34%10%14%25%14%3
2772
February1st to 10thNight
38%9%14%22%14%2
2372
11th to 20thNight
35%7%15%25%15%3
2144
21st to endNight
35%6%13%25%14%7%
1776
March1st to 10thNight
32%8%13%28%17%3
2160
11th to 20thNight
32%7%12%27%20%2
2113
21st to endNight
40%7%15%24%13%1
1980
April1st to 10thNight
38%7%15%22%15%3
1800
11th to 20thNight
38%6%13%26%15%2
1777
21st to endNight
36%8%14%28%13%1
1666
May1st to 10thNight
33%6%15%32%13%1
1546
11th to 20thNight
36%6%16%30%12%
1418
21st to endNight
37%8%16%27%10%1
1552
June1st to 10thNight
29%7%19%30%13%2
1440
11th to 20thNight
30%9%21%23%14%3
1440
21st to endNight
23%7%17%26%22%5%
1440
July1st to 10thNight
22%7%15%32%19%4
1400
11th to 20thNight
21%5%11%25%27%11%
1392
21st to endNight
18%5%13%29%27%8%
1488
August1st to 10thNight
26%7%12%28%21%7%
1424
11th to 20thNight
21%411%27%29%8%
1662
21st to endNight
18%5%11%26%31%10%
1980
September1st to 10thNight
21%5%7%29%26%11%
1800
11th to 20thNight
23%5%10%27%25%9%
1872
21st to endNight
26%48%30%26%6%
1980
October1st to 10thNight
33%5%13%25%20%5%
2076
11th to 20thNight
28%7%9%27%22%7%
2175
21st to endNight
29%5%15%26%19%6%
2574
November1st to 10thNight
30%6%14%24%20%6%
2405
11th to 20thNight
27%6%11%28%22%5%
2484
21st to endNight
26%6%14%29%20%4
2660
December1st to 10thNight
30%8%13%29%16%4
2660
11th to 20thNight
24%8%14%39%14%1
3272
21st to endNight
35%7%10%32%14%2
4873

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
9%12%31%26%14%8%
270
11th to 20thDay
17%14%28%27%11%4
255
21st to endDay
14%29%31%20%5%1
264
February1st to 10thDay
15%20%40%18%6%1
240
11th to 20thDay
13%17%37%27%7%
240
21st to endDay
9%20%39%26%6%1
198
March1st to 10thDay
12%16%39%20%10%3
240
11th to 20thDay
13%13%35%22%14%3
276
21st to endDay
20%14%31%24%10%2
462
April1st to 10thDay
20%14%34%26%5%1
420
11th to 20thDay
21%20%38%17%3
412
21st to endDay
20%12%29%26%12%2
554
May1st to 10thDay
18%13%29%23%14%3
603
11th to 20thDay
21%9%24%26%14%5%
625
21st to endDay
19%9%32%24%12%5%
679
June1st to 10thDay
9%7%27%33%19%6%
630
11th to 20thDay
11%11%33%31%13%2
630
21st to endDay
8%9%28%33%19%4
630
July1st to 10thDay
5%324%41%23%3
621
11th to 20thDay
47%29%37%19%3
618
21st to endDay
5%6%25%37%23%4
684
August1st to 10thDay
6%428%40%18%4
626
11th to 20thDay
6%5%26%39%18%5%
507
21st to endDay
49%26%35%20%6%
495
September1st to 10thDay
7%8%29%36%15%4
450
11th to 20thDay
9%6%27%34%18%6%
378
21st to endDay
15%11%29%26%12%7%
270
October1st to 10thDay
18%11%23%26%16%5%
270
11th to 20thDay
21%15%28%20%12%5%
270
21st to endDay
12%23%27%23%13%2
297
November1st to 10thDay
13%17%34%19%13%4
270
11th to 20thDay
14%14%36%21%12%3
270
21st to endDay
12%21%24%27%13%2
270
December1st to 10thDay
14%18%34%24%8%3
270
11th to 20thDay
13%17%37%24%9%
270
21st to endDay
12%15%35%27%8%1
297
January1st to 10thNight
7%18%32%29%13%1
950
11th to 20thNight
11%21%31%26%10%2
926
21st to endNight
9%23%35%26%6%1
990
February1st to 10thNight
11%19%34%28%8%1
752
11th to 20thNight
8%19%36%28%9%1
704
21st to endNight
9%12%37%30%10%1
592
March1st to 10thNight
11%13%35%32%8%1
720
11th to 20thNight
10%10%35%34%10%1
712
21st to endNight
16%10%29%35%9%1
594
April1st to 10thNight
14%11%32%34%9%
540
11th to 20thNight
19%12%35%28%6%1
533
21st to endNight
15%12%29%32%11%1
540
May1st to 10thNight
13%9%27%35%14%2
540
11th to 20thNight
16%7%24%36%15%2
531
21st to endNight
19%8%34%28%11%1
584
June1st to 10thNight
12%7%26%38%16%1
540
11th to 20thNight
11%6%38%35%10%
540
21st to endNight
8%5%26%49%12%
540
July1st to 10thNight
6%324%46%20%2
525
11th to 20thNight
5%427%50%15%
522
21st to endNight
3222%54%18%
591
August1st to 10thNight
5%321%54%16%1
537
11th to 20thNight
5%323%45%22%1
534
21st to endNight
5%5%21%45%23%2
594
September1st to 10thNight
7%421%46%19%3
540
11th to 20thNight
9%5%22%43%19%2
540
21st to endNight
12%8%27%37%14%1
540
October1st to 10thNight
15%10%24%34%15%2
636
11th to 20thNight
14%13%30%30%13%1
735
21st to endNight
14%16%32%27%10%2
990
November1st to 10thNight
9%15%33%32%9%2
925
11th to 20thNight
11%17%31%31%9%1
950
21st to endNight
8%20%33%30%8%1
950
December1st to 10thNight
9%20%34%27%9%1
950
11th to 20thNight
8%16%35%31%9%1
950
21st to endNight
14%18%32%28%8%1
1045
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