Washington County State Recreational Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Washington County State Recreational Area clear sky chart from 2005-11-06 to 2024-01-22.

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%
24386
22%
74729
15%
24328
50%
24328
27%
46817

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
24%
949
20%
2648
7%
946
35%
946
22%
1790
January11th to 20thNight
20%
950
19%
2594
7%
950
29%
950
20%
1847
January21st to endNight
22%
1000
20%
2600
6%
1000
31%
1000
24%
1820
February1st to 10thNight
23%
833
16%
2273
5%
833
30%
833
20%
1661
February11th to 20thNight
22%
702
20%
2099
8%
700
32%
700
22%
1371
February21st to endNight
21%
592
19%
1776
6%
592
31%
592
20%
1197
March1st to 10thNight
24%
720
20%
2160
7%
720
35%
720
24%
1399
March11th to 20thNight
27%
608
17%
2048
10%
608
36%
608
19%
1357
March21st to endNight
31%
594
15%
2015
10%
594
39%
594
19%
1367
April1st to 10thNight
34%
540
23%
1800
14%
540
47%
540
27%
1048
April11th to 20thNight
40%
533
24%
1775
19%
533
50%
533
28%
1063
April21st to endNight
32%
540
19%
1800
12%
540
43%
540
22%
1171
May1st to 10thNight
42%
540
18%
1688
12%
540
49%
540
26%
1069
May11th to 20thNight
49%
531
19%
1545
15%
531
53%
531
29%
997
May21st to endNight
57%
584
20%
1551
14%
582
61%
582
32%
1018
June1st to 10thNight
63%
540
20%
1440
15%
540
66%
540
38%
871
June11th to 20thNight
70%
540
29%
1440
21%
540
73%
540
46%
795
June21st to endNight
67%
540
26%
1440
19%
540
71%
540
46%
815
July1st to 10thNight
73%
525
20%
1400
18%
525
73%
525
40%
839
July11th to 20thNight
76%
522
24%
1392
21%
522
78%
522
44%
798
July21st to endNight
71%
591
26%
1538
22%
558
73%
558
43%
876
August1st to 10thNight
76%
537
23%
1686
26%
534
76%
534
38%
926
August11th to 20thNight
74%
534
26%
1776
30%
534
76%
534
37%
952
August21st to endNight
76%
594
28%
1980
32%
594
78%
594
40%
1017
September1st to 10thNight
66%
540
28%
1800
29%
540
70%
540
35%
993
September11th to 20thNight
69%
594
35%
1854
34%
594
72%
594
39%
1024
September21st to endNight
60%
720
31%
1980
22%
720
65%
720
39%
1164
October1st to 10thNight
59%
720
30%
2073
22%
720
64%
720
42%
1137
October11th to 20thNight
42%
720
32%
2160
19%
720
55%
720
34%
1244
October21st to endNight
35%
792
25%
2448
16%
792
45%
792
25%
1541
November1st to 10thNight
42%
740
29%
2406
20%
740
54%
740
36%
1288
November11th to 20thNight
36%
760
28%
2470
18%
760
51%
760
30%
1412
November21st to endNight
32%
760
24%
2470
16%
760
43%
760
25%
1528
December1st to 10thNight
30%
912
18%
2622
8%
912
39%
912
23%
1763
December11th to 20thNight
32%
948
21%
3149
10%
948
40%
948
21%
2036
December21st to endNight
21%
1041
11%
4833
7%
1026
31%
1026
10%
3623

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
12%7%35%5%35%5%5%8%42%
74848
Night
13%7%36%5%3445%7%44%
75097
TransparencyDay
41%311%26%16%3
74553
Night
41%310%25%18%3
74913
SeeingDay
15%8%22%26%20%8%
14438
Night
17%8%27%32%16%2
24394

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
14%9%48%6%26%5%45%36%
1517
11th to 20thDay
17%9%46%6%3445%6%35%
1581
21st to endDay
12%10%5%7%7%35%446%37%
1791
February1st to 10thDay
18%9%5%6%435%446%36%
1684
11th to 20thDay
15%9%47%6%25%45%6%36%
1748
21st to endDay
15%10%47%43445%7%37%
1480
March1st to 10thDay
15%7%45%5%35%5%46%42%
1800
11th to 20thDay
20%9%36%5%34445%37%
1926
21st to endDay
19%9%47%7%45%5%5%6%30%
2340
April1st to 10thDay
11%5%26%5%3447%8%44%
2160
11th to 20thDay
16%9%35%5%25%45%6%41%
2134
21st to endDay
18%6%36%5%35%5%46%39%
2160
May1st to 10thDay
16%6%36%5%45%5%5%8%37%
2269
11th to 20thDay
16%6%25%5%35%5%5%6%40%
2345
21st to endDay
9%6%36%7%36%6%8%10%37%
2725
June1st to 10thDay
8%5%25%5%35%5%6%9%47%
2520
11th to 20thDay
6%4245%36%5%7%10%49%
2520
21st to endDay
4425%5%45%6%7%11%46%
2520
July1st to 10thDay
10%425%5%45%6%8%10%41%
2520
11th to 20thDay
5%325%6%35%5%8%11%47%
2520
21st to endDay
7%425%6%45%6%6%9%47%
2685
August1st to 10thDay
7%425%5%46%5%7%10%45%
2239
11th to 20thDay
9%436%5%35%6%7%10%43%
2125
21st to endDay
6%5%35%5%35%5%7%9%48%
2376
September1st to 10thDay
12%435%4345%48%49%
2160
11th to 20thDay
7%5%25%4346%5%9%48%
2087
21st to endDay
10%4235%2446%6%54%
1980
October1st to 10thDay
10%424433446%56%
1884
11th to 20thDay
13%5%245%33348%50%
1800
21st to endDay
17%7%34433446%46%
1905
November1st to 10thDay
9%5%24434436%55%
1672
11th to 20thDay
15%7%35%424346%47%
1710
21st to endDay
17%10%36%5%24445%41%
1710
December1st to 10thDay
14%10%46%5%34447%39%
1554
11th to 20thDay
15%10%45%5%35%5%5%5%37%
1918
21st to endDay
21%14%5%7%6%34445%27%
2783
January1st to 10thNight
15%8%37%5%45%5%5%7%37%
2648
11th to 20thNight
16%10%48%5%35%445%35%
2594
21st to endNight
14%9%48%6%35%446%36%
2600
February1st to 10thNight
18%10%5%8%435%346%33%
2273
11th to 20thNight
16%7%36%6%34446%42%
2098
21st to endNight
19%8%37%5%3445%5%38%
1776
March1st to 10thNight
16%8%35%5%3445%5%43%
2160
11th to 20thNight
18%7%47%5%3345%6%37%
2048
21st to endNight
20%8%37%6%3445%7%34%
2015
April1st to 10thNight
12%5%35%5%24447%48%
1800
11th to 20thNight
15%6%35%5%3345%8%43%
1775
21st to endNight
19%7%35%5%35%35%5%40%
1800
May1st to 10thNight
16%5%35%5%4445%7%42%
1688
11th to 20thNight
12%7%35%5%3445%6%44%
1544
21st to endNight
8%5%36%6%46%5%8%10%39%
1551
June1st to 10thNight
7%5%26%5%35%5%5%9%48%
1440
11th to 20thNight
3423435%5%6%10%55%
1440
21st to endNight
4224436%5%7%11%52%
1440
July1st to 10thNight
8%424435%7%6%9%50%
1440
11th to 20thNight
6%3245%345%6%10%53%
1440
21st to endNight
6%424435%5%5%10%51%
1629
August1st to 10thNight
6%3145%35%6%5%10%51%
1696
11th to 20thNight
5%335%5%35%5%7%9%50%
1776
21st to endNight
5%42443445%8%56%
1980
September1st to 10thNight
11%5%35%42345%6%54%
1800
11th to 20thNight
6%4345%25%46%8%52%
1854
21st to endNight
10%424434447%53%
1980
October1st to 10thNight
7%5%14424447%57%
2073
11th to 20thNight
13%425%433345%54%
2160
21st to endNight
18%8%35%324435%46%
2448
November1st to 10thNight
10%5%24323346%56%
2406
11th to 20thNight
14%6%24423446%51%
2470
21st to endNight
18%7%35%423346%45%
2470
December1st to 10thNight
17%10%45%4345%6%6%37%
2622
11th to 20thNight
17%6%46%5%34445%42%
3279
21st to endNight
20%15%5%8%6%45%445%25%
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
51%39%22%12%2
1518
11th to 20thDay
51%210%26%10%
1581
21st to endDay
50%210%26%10%2
1791
February1st to 10thDay
51%211%24%11%1
1684
11th to 20thDay
50%310%21%13%3
1758
21st to endDay
48%39%23%13%3
1480
March1st to 10thDay
44%39%26%15%3
1800
11th to 20thDay
52%211%21%12%2
1926
21st to endDay
55%312%19%9%1
2340
April1st to 10thDay
38%411%30%17%1
2160
11th to 20thDay
46%39%25%15%3
2134
21st to endDay
47%310%26%11%2
2160
May1st to 10thDay
46%5%14%25%9%1
2269
11th to 20thDay
44%413%23%14%1
2349
21st to endDay
41%5%15%24%13%2
2725
June1st to 10thDay
35%413%29%17%2
2520
11th to 20thDay
30%5%14%27%22%3
2520
21st to endDay
30%5%18%24%17%5%
2520
July1st to 10thDay
35%5%15%27%13%5%
2451
11th to 20thDay
29%415%30%18%3
2445
21st to endDay
33%5%11%32%16%2
2536
August1st to 10thDay
33%5%13%31%17%1
2225
11th to 20thDay
35%414%31%14%1
2125
21st to endDay
32%413%27%19%6%
2376
September1st to 10thDay
35%311%29%18%5%
2160
11th to 20thDay
33%38%29%24%3
2087
21st to endDay
31%38%28%26%4
1980
October1st to 10thDay
30%39%29%26%4
1884
11th to 20thDay
35%28%26%23%5%
1800
21st to endDay
42%27%29%17%4
1905
November1st to 10thDay
33%311%28%20%6%
1672
11th to 20thDay
41%28%24%20%5%
1710
21st to endDay
47%28%25%17%2
1710
December1st to 10thDay
47%211%25%14%1
1554
11th to 20thDay
50%27%25%13%3
1915
21st to endDay
62%210%16%9%2
2783
January1st to 10thNight
47%38%26%14%1
2648
11th to 20thNight
52%39%23%12%1
2594
21st to endNight
50%210%24%13%1
2600
February1st to 10thNight
54%38%22%12%1
2273
11th to 20thNight
46%39%23%17%2
2099
21st to endNight
49%210%22%13%3
1776
March1st to 10thNight
44%38%22%19%4
2160
11th to 20thNight
49%310%21%14%3
2048
21st to endNight
51%314%21%10%1
2015
April1st to 10thNight
37%411%28%18%3
1800
11th to 20thNight
40%210%24%19%4
1775
21st to endNight
48%29%24%15%3
1800
May1st to 10thNight
43%311%26%14%2
1688
11th to 20thNight
41%413%24%16%2
1545
21st to endNight
38%7%14%22%16%4
1552
June1st to 10thNight
33%413%25%22%3
1440
11th to 20thNight
26%411%28%25%7%
1440
21st to endNight
26%415%28%19%7%
1440
July1st to 10thNight
31%5%16%27%16%6%
1400
11th to 20thNight
27%5%13%30%20%5%
1392
21st to endNight
29%414%32%19%2
1538
August1st to 10thNight
29%416%30%19%2
1686
11th to 20thNight
30%413%28%23%3
1776
21st to endNight
27%313%27%23%6%
1980
September1st to 10thNight
33%37%31%19%7%
1800
11th to 20thNight
31%36%32%24%4
1854
21st to endNight
32%37%23%30%6%
1980
October1st to 10thNight
28%39%25%29%6%
2073
11th to 20thNight
35%26%26%24%7%
2160
21st to endNight
43%26%23%20%5%
2448
November1st to 10thNight
32%211%26%24%6%
2406
11th to 20thNight
36%28%25%24%5%
2470
21st to endNight
43%29%26%19%2
2470
December1st to 10thNight
48%211%24%14%1
2622
11th to 20thNight
46%210%25%17%1
3281
21st to endNight
64%18%17%9%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
22%18%29%22%8%
270
11th to 20thDay
29%15%34%19%3
270
21st to endDay
16%20%40%18%5%
267
February1st to 10thDay
26%12%43%15%4
240
11th to 20thDay
26%19%34%15%6%
240
21st to endDay
26%16%35%21%21
198
March1st to 10thDay
20%18%40%17%5%
240
11th to 20thDay
30%9%38%17%5%
240
21st to endDay
28%15%30%19%7%1
426
April1st to 10thDay
15%15%35%26%10%1
420
11th to 20thDay
21%13%28%23%13%2
412
21st to endDay
22%11%31%23%10%2
420
May1st to 10thDay
18%13%27%28%10%3
423
11th to 20thDay
19%7%23%28%18%5%
491
21st to endDay
10%323%33%20%11%
679
June1st to 10thDay
10%417%26%29%13%
630
11th to 20thDay
7%218%34%27%11%
630
21st to endDay
7%321%34%26%10%
630
July1st to 10thDay
11%29%24%28%26%
621
11th to 20thDay
6%210%32%35%15%
618
21st to endDay
9%39%30%33%15%
684
August1st to 10thDay
10%28%30%32%18%
537
11th to 20thDay
11%411%27%34%13%
439
21st to endDay
11%38%24%34%20%
495
September1st to 10thDay
13%212%26%33%13%
450
11th to 20thDay
7%28%29%36%17%
450
21st to endDay
11%6%20%26%25%13%
450
October1st to 10thDay
12%5%20%36%21%6%
354
11th to 20thDay
16%14%33%22%13%2
270
21st to endDay
28%14%29%21%9%
297
November1st to 10thDay
11%9%32%26%17%5%
270
11th to 20thDay
16%17%27%26%11%2
270
21st to endDay
27%11%27%24%10%2
270
December1st to 10thDay
15%18%34%20%8%5%
270
11th to 20thDay
22%17%29%24%7%1
270
21st to endDay
29%15%36%16%4
297
January1st to 10thNight
20%14%36%26%5%
950
11th to 20thNight
22%14%37%22%4
950
21st to endNight
19%12%41%25%2
1000
February1st to 10thNight
24%12%36%27%2
833
11th to 20thNight
21%14%38%25%2
703
21st to endNight
23%14%35%26%2
592
March1st to 10thNight
21%13%38%25%4
720
11th to 20thNight
23%10%33%28%7%
608
21st to endNight
25%8%29%30%8%
594
April1st to 10thNight
16%11%36%31%6%
540
11th to 20thNight
17%10%29%31%12%1
533
21st to endNight
23%7%32%27%10%1
540
May1st to 10thNight
18%428%37%11%1
540
11th to 20thNight
15%5%24%34%20%3
531
21st to endNight
9%320%40%24%4
584
June1st to 10thNight
11%215%40%31%1
540
11th to 20thNight
5%117%46%28%3
540
21st to endNight
5%219%41%31%2
540
July1st to 10thNight
9%28%33%41%9%
525
11th to 20thNight
7%17%43%37%5%
522
21st to endNight
9%39%40%34%6%
591
August1st to 10thNight
8%27%40%38%6%
537
11th to 20thNight
7%28%37%40%6%
534
21st to endNight
7%26%35%46%5%
594
September1st to 10thNight
13%210%35%34%6%
540
11th to 20thNight
8%211%37%37%6%
594
21st to endNight
12%419%32%27%6%
720
October1st to 10thNight
8%422%37%23%5%
720
11th to 20thNight
16%7%28%33%14%2
720
21st to endNight
22%11%29%30%8%1
792
November1st to 10thNight
13%5%34%35%12%1
740
11th to 20thNight
16%11%32%31%9%1
760
21st to endNight
22%9%33%27%9%
760
December1st to 10thNight
23%11%31%30%5%
912
11th to 20thNight
23%7%31%32%6%
950
21st to endNight
27%11%36%23%4
1045
Page generated at 2024-01-19 08:28:37. Version ac07

Copyright 2024 Attilla Danko


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