Adams Observing Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Adams Observing Site 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
40%
23983
19%
80092
13%
23878
47%
23878
20%
53590

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
17%
754
13%
4063
7%
737
27%
737
7%
3023
January11th to 20thNight
17%
760
17%
4023
8%
740
26%
740
6%
2966
January21st to endNight
17%
831
10%
4478
7%
814
28%
814
7%
3269
February1st to 10thNight
20%
760
14%
2387
6%
760
30%
760
15%
1774
February11th to 20thNight
16%
743
15%
2219
6%
740
24%
740
14%
1615
February21st to endNight
13%
628
14%
1884
5%
628
22%
628
12%
1422
March1st to 10thNight
23%
723
20%
2112
9%
723
33%
723
19%
1427
March11th to 20thNight
23%
720
17%
1980
7%
720
32%
720
18%
1415
March21st to endNight
28%
792
15%
2178
8%
792
34%
792
19%
1552
April1st to 10thNight
35%
664
21%
1924
11%
664
44%
664
26%
1237
April11th to 20thNight
36%
533
24%
1703
14%
533
47%
533
26%
1056
April21st to endNight
32%
540
19%
1620
7%
540
42%
540
22%
1091
May1st to 10thNight
36%
540
16%
1620
9%
540
42%
540
20%
1103
May11th to 20thNight
45%
531
16%
1592
11%
531
49%
531
23%
1089
May21st to endNight
59%
583
18%
1745
14%
582
63%
582
30%
1086
June1st to 10thNight
60%
540
18%
1620
15%
540
65%
540
34%
978
June11th to 20thNight
63%
540
18%
1620
16%
540
65%
540
33%
956
June21st to endNight
61%
540
18%
1620
16%
540
63%
540
32%
991
July1st to 10thNight
62%
525
14%
1575
13%
525
63%
525
28%
1004
July11th to 20thNight
70%
522
19%
1566
17%
522
72%
522
35%
925
July21st to endNight
68%
591
21%
1672
18%
558
70%
558
31%
1042
August1st to 10thNight
71%
537
22%
1600
20%
534
72%
534
35%
939
August11th to 20thNight
67%
534
22%
1598
20%
534
69%
534
32%
980
August21st to endNight
70%
594
24%
1924
24%
594
72%
594
36%
1058
September1st to 10thNight
65%
679
23%
1939
20%
679
67%
679
33%
1179
September11th to 20thNight
63%
720
28%
1980
22%
720
67%
720
37%
1190
September21st to endNight
52%
720
27%
1980
20%
720
58%
720
32%
1249
October1st to 10thNight
58%
720
28%
1980
24%
720
62%
720
38%
1161
October11th to 20thNight
43%
720
26%
2158
20%
720
52%
720
29%
1337
October21st to endNight
35%
792
25%
2431
18%
792
46%
792
23%
1592
November1st to 10thNight
46%
740
27%
2406
23%
740
55%
740
29%
1419
November11th to 20thNight
33%
760
25%
2470
16%
760
45%
760
23%
1545
November21st to endNight
35%
760
22%
2470
15%
760
44%
760
21%
1632
December1st to 10thNight
23%
760
14%
2470
7%
760
32%
760
14%
1779
December11th to 20thNight
27%
759
18%
2986
12%
759
36%
759
13%
2080
December21st to endNight
22%
828
9%
4499
8%
817
32%
817
7%
3429

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%9%36%5%35%5%5%7%36%
78838
Night
15%9%36%5%3445%7%38%
80585
TransparencyDay
48%5%10%22%14%2
78561
Night
47%5%10%22%15%3
80381
SeeingDay
23%10%25%22%14%6%
13826
Night
21%9%23%28%17%2
24004

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
17%17%6%9%6%3445%6%23%
2836
11th to 20thDay
17%16%8%12%8%3333423%
2840
21st to endDay
27%18%6%6%423345%23%
3124
February1st to 10thDay
20%12%410%6%35%335%30%
1790
11th to 20thDay
20%10%5%9%5%35%35%5%30%
1848
21st to endDay
21%12%46%6%24445%31%
1570
March1st to 10thDay
19%10%35%43445%5%37%
1854
11th to 20thDay
21%9%47%7%3445%6%32%
1980
21st to endDay
21%9%36%6%3445%6%32%
2178
April1st to 10thDay
15%8%46%7%3435%7%39%
2051
11th to 20thDay
18%7%36%5%34447%39%
2204
21st to endDay
18%7%35%5%445%5%7%36%
2340
May1st to 10thDay
19%7%26%6%45%5%5%7%34%
2340
11th to 20thDay
18%7%46%6%45%5%5%6%34%
2301
21st to endDay
9%6%26%6%46%5%8%11%36%
2531
June1st to 10thDay
12%6%25%5%45%6%6%8%42%
2340
11th to 20thDay
9%5%26%6%46%6%6%9%41%
2340
21st to endDay
11%5%26%6%46%6%7%10%39%
2340
July1st to 10thDay
13%6%26%6%35%6%7%10%36%
2340
11th to 20thDay
10%6%36%6%46%6%6%10%37%
2340
21st to endDay
12%6%345%47%7%7%8%37%
2547
August1st to 10thDay
11%6%246%45%6%6%10%41%
2327
11th to 20thDay
11%6%36%6%46%6%7%10%34%
2303
21st to endDay
9%4246%45%5%7%10%43%
2429
September1st to 10thDay
13%5%35%5%3445%8%44%
2003
11th to 20thDay
11%5%24435%45%9%47%
1980
21st to endDay
17%5%35%433446%47%
1980
October1st to 10thDay
11%5%2443445%8%51%
1980
11th to 20thDay
15%6%25%323445%48%
1801
21st to endDay
22%7%36%323446%41%
1922
November1st to 10thDay
12%7%25%433345%54%
1672
11th to 20thDay
15%9%36%43445%5%42%
1710
21st to endDay
18%9%46%5%34446%39%
1710
December1st to 10thDay
24%12%5%8%5%3446%5%27%
1710
11th to 20thDay
17%13%5%7%5%44445%33%
2153
21st to endDay
20%16%5%8%7%445%5%7%21%
3124
January1st to 10thNight
16%17%6%9%7%3445%5%24%
4109
11th to 20thNight
20%16%5%10%6%2333427%
4120
21st to endNight
23%14%7%7%5%33345%27%
4532
February1st to 10thNight
21%12%47%6%35%445%29%
2387
11th to 20thNight
22%10%38%6%34446%31%
2218
21st to endNight
24%12%48%5%34445%29%
1884
March1st to 10thNight
18%9%46%5%3435%5%40%
2112
11th to 20thNight
20%9%36%5%35%45%6%34%
1980
21st to endNight
16%8%47%6%35%45%7%34%
2178
April1st to 10thNight
15%6%245%35%5%6%7%42%
1924
11th to 20thNight
14%7%35%5%3346%7%44%
1703
21st to endNight
17%6%36%5%35%45%6%39%
1620
May1st to 10thNight
17%6%36%5%46%5%5%7%35%
1620
11th to 20thNight
15%6%26%6%36%5%6%9%37%
1592
21st to endNight
8%5%25%6%46%7%6%10%42%
1744
June1st to 10thNight
7%5%245%35%6%7%9%46%
1620
11th to 20thNight
6%325%5%45%6%7%9%48%
1620
21st to endNight
9%424436%5%7%11%44%
1620
July1st to 10thNight
10%5%35%5%45%46%10%42%
1620
11th to 20thNight
5%5%25%5%45%6%8%10%47%
1620
21st to endNight
9%425%6%45%5%6%8%45%
1771
August1st to 10thNight
7%426%435%5%7%11%47%
1611
11th to 20thNight
8%5%35%5%36%5%8%11%42%
1598
21st to endNight
7%5%2443446%9%52%
1924
September1st to 10thNight
11%5%245%345%5%8%48%
1939
11th to 20thNight
9%6%25%5%3446%7%50%
1980
21st to endNight
11%5%26%6%34436%48%
1980
October1st to 10thNight
11%42443445%7%53%
1980
11th to 20thNight
16%5%2443345%7%46%
2158
21st to endNight
19%7%35%5%24445%42%
2431
November1st to 10thNight
13%7%25%433435%51%
2406
11th to 20thNight
17%7%35%424446%44%
2470
21st to endNight
18%10%34434446%40%
2470
December1st to 10thNight
22%13%46%43445%6%30%
2470
11th to 20thNight
18%11%6%7%5%3435%5%33%
3042
21st to endNight
19%17%48%6%45%5%5%6%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
61%5%9%15%9%1
2837
11th to 20thDay
67%36%18%6%1
2840
21st to endDay
66%36%20%5%1
3124
February1st to 10thDay
59%38%18%11%1
1790
11th to 20thDay
57%47%19%11%2
1858
21st to endDay
55%38%20%11%3
1570
March1st to 10thDay
49%39%23%14%2
1854
11th to 20thDay
55%48%18%12%3
1980
21st to endDay
54%48%22%9%2
2178
April1st to 10thDay
46%49%25%13%3
2051
11th to 20thDay
46%48%21%16%5%
2204
21st to endDay
48%6%10%22%11%3
2340
May1st to 10thDay
50%5%11%24%9%2
2340
11th to 20thDay
51%5%10%21%11%1
2305
21st to endDay
40%8%16%22%13%1
2531
June1st to 10thDay
39%7%11%27%16%1
2340
11th to 20thDay
38%6%14%21%17%2
2340
21st to endDay
40%7%13%21%16%3
2340
July1st to 10thDay
42%7%15%18%16%1
2275
11th to 20thDay
42%7%13%22%15%2
2271
21st to endDay
41%7%13%25%12%2
2405
August1st to 10thDay
38%7%16%25%13%1
2314
11th to 20thDay
43%6%13%24%13%1
2303
21st to endDay
34%7%16%24%16%4
2429
September1st to 10thDay
38%5%13%21%17%6%
2003
11th to 20thDay
36%311%26%22%2
1980
21st to endDay
39%38%26%22%2
1980
October1st to 10thDay
33%410%26%24%3
1980
11th to 20thDay
38%47%25%22%3
1801
21st to endDay
45%38%25%16%2
1922
November1st to 10thDay
35%38%27%23%4
1672
11th to 20thDay
45%27%22%19%4
1710
21st to endDay
49%38%22%18%2
1710
December1st to 10thDay
60%39%19%8%1
1710
11th to 20thDay
55%48%18%14%1
2150
21st to endDay
63%5%9%16%5%1
3124
January1st to 10thNight
62%5%7%16%9%1
4109
11th to 20thNight
63%35%19%9%2
4120
21st to endNight
62%37%19%8%1
4532
February1st to 10thNight
58%38%20%9%1
2387
11th to 20thNight
56%37%20%12%1
2219
21st to endNight
60%39%14%10%3
1884
March1st to 10thNight
48%37%21%19%3
2112
11th to 20thNight
51%49%22%12%2
1980
21st to endNight
51%5%11%21%11%2
2178
April1st to 10thNight
39%6%10%25%18%2
1924
11th to 20thNight
39%5%10%20%19%7%
1703
21st to endNight
46%5%11%22%14%2
1620
May1st to 10thNight
48%5%11%22%10%4
1620
11th to 20thNight
44%8%13%21%12%2
1593
21st to endNight
36%7%16%22%16%2
1745
June1st to 10thNight
31%8%15%26%16%4
1620
11th to 20thNight
31%8%15%24%19%3
1620
21st to endNight
34%8%15%25%14%5%
1620
July1st to 10thNight
38%8%14%20%17%4
1575
11th to 20thNight
31%7%15%24%19%4
1566
21st to endNight
35%8%11%29%15%1
1672
August1st to 10thNight
31%7%16%28%16%2
1600
11th to 20thNight
35%7%15%28%14%1
1598
21st to endNight
28%7%14%27%19%5%
1924
September1st to 10thNight
34%6%12%23%18%7%
1939
11th to 20thNight
33%411%25%24%3
1980
21st to endNight
37%5%7%22%26%3
1980
October1st to 10thNight
31%5%11%25%23%5%
1980
11th to 20thNight
38%48%24%22%4
2158
21st to endNight
45%46%23%19%4
2431
November1st to 10thNight
36%47%25%23%4
2406
11th to 20thNight
43%37%20%22%5%
2470
21st to endNight
47%48%25%15%2
2470
December1st to 10thNight
56%310%19%11%1
2470
11th to 20thNight
55%38%22%11%1
3044
21st to endNight
64%6%8%15%8%
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
33%19%31%13%31
270
11th to 20thDay
41%16%30%12%
270
21st to endDay
36%23%28%10%3
297
February1st to 10thDay
33%21%31%12%2
270
11th to 20thDay
41%22%29%6%2
270
21st to endDay
38%15%39%8%
225
March1st to 10thDay
35%18%31%12%3
294
11th to 20thDay
30%20%30%16%5%
420
21st to endDay
35%15%29%16%6%
462
April1st to 10thDay
27%15%29%18%9%2
420
11th to 20thDay
26%14%28%20%7%4
412
21st to endDay
27%15%31%18%6%3
420
May1st to 10thDay
29%15%27%17%9%4
423
11th to 20thDay
22%9%30%22%13%5%
447
21st to endDay
15%6%24%28%18%9%
485
June1st to 10thDay
16%423%31%17%8%
450
11th to 20thDay
14%6%24%32%17%9%
450
21st to endDay
14%6%25%26%18%10%
450
July1st to 10thDay
18%215%23%20%22%
445
11th to 20thDay
14%317%31%19%16%
444
21st to endDay
15%217%29%22%15%
488
August1st to 10thDay
16%217%26%27%13%
446
11th to 20thDay
15%315%31%23%13%
439
21st to endDay
12%314%31%27%14%
495
September1st to 10thDay
17%212%26%30%13%
450
11th to 20thDay
14%213%27%32%12%
450
21st to endDay
21%7%20%23%23%7%
450
October1st to 10thDay
16%5%21%30%21%7%
450
11th to 20thDay
19%12%27%26%13%3
450
21st to endDay
31%7%30%23%9%1
437
November1st to 10thDay
19%9%37%25%7%4
270
11th to 20thDay
32%10%32%18%7%1
270
21st to endDay
28%13%36%16%6%1
270
December1st to 10thDay
34%17%29%15%5%1
270
11th to 20thDay
32%14%32%17%5%
270
21st to endDay
37%17%31%12%4
297
January1st to 10thNight
29%18%29%19%5%
760
11th to 20thNight
34%17%28%19%3
760
21st to endNight
27%18%32%22%2
836
February1st to 10thNight
31%14%30%22%3
760
11th to 20thNight
33%17%31%17%2
743
21st to endNight
35%14%34%16%2
628
March1st to 10thNight
27%15%29%23%6%
723
11th to 20thNight
29%16%28%20%7%1
720
21st to endNight
24%13%29%26%8%
792
April1st to 10thNight
23%11%28%28%10%
664
11th to 20thNight
20%11%27%28%12%2
533
21st to endNight
21%8%33%28%9%1
540
May1st to 10thNight
22%7%26%29%12%3
540
11th to 20thNight
18%5%23%35%19%1
531
21st to endNight
10%219%34%28%5%
584
June1st to 10thNight
10%317%42%25%3
540
11th to 20thNight
7%315%40%30%5%
540
21st to endNight
12%217%38%27%4
540
July1st to 10thNight
14%111%28%34%12%
525
11th to 20thNight
8%111%36%39%5%
522
21st to endNight
12%19%33%38%6%
591
August1st to 10thNight
9%17%36%40%7%
537
11th to 20thNight
11%17%35%38%7%
534
21st to endNight
11%19%33%39%8%
594
September1st to 10thNight
14%19%33%37%7%
679
11th to 20thNight
15%211%30%36%6%
720
21st to endNight
14%419%31%29%3
720
October1st to 10thNight
14%419%31%27%5%
720
11th to 20thNight
20%7%24%30%16%2
720
21st to endNight
24%9%27%26%12%1
792
November1st to 10thNight
17%8%24%32%17%2
740
11th to 20thNight
24%12%28%26%11%
760
21st to endNight
26%10%24%29%10%1
760
December1st to 10thNight
32%13%26%24%5%
760
11th to 20thNight
25%14%28%26%6%1
760
21st to endNight
32%14%27%24%4
836
Page generated at 2024-02-27 06:30:15. Version ac07

Copyright © 2024 Attilla Danko.


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