Asteroid Hunter Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Asteroid Hunter Observatory 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
48%
24059
28%
74353
19%
24001
58%
24001
37%
40769

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
36%
948
31%
2458
12%
946
48%
946
41%
1436
January11th to 20thNight
35%
950
29%
2470
10%
950
46%
950
36%
1467
January21st to endNight
34%
1000
33%
2600
13%
1000
46%
1000
37%
1565
February1st to 10thNight
31%
806
26%
2246
10%
806
42%
806
31%
1359
February11th to 20thNight
27%
704
23%
2098
8%
700
38%
700
29%
1278
February21st to endNight
22%
572
28%
1756
9%
572
37%
572
27%
1044
March1st to 10thNight
30%
540
26%
1980
14%
540
45%
540
25%
1147
March11th to 20thNight
32%
540
24%
1980
13%
540
45%
540
26%
1127
March21st to endNight
32%
594
26%
2178
14%
594
49%
594
29%
1180
April1st to 10thNight
31%
540
26%
1980
14%
540
50%
540
32%
1009
April11th to 20thNight
32%
533
25%
1861
16%
533
46%
533
29%
1036
April21st to endNight
34%
540
29%
1659
16%
540
51%
540
37%
913
May1st to 10thNight
38%
540
26%
1620
17%
540
51%
540
33%
963
May11th to 20thNight
44%
531
20%
1594
17%
531
52%
531
33%
957
May21st to endNight
50%
584
24%
1745
19%
582
62%
582
37%
1008
June1st to 10thNight
71%
540
23%
1620
23%
540
75%
540
45%
844
June11th to 20thNight
65%
540
26%
1620
27%
540
71%
540
53%
798
June21st to endNight
72%
540
27%
1620
28%
540
76%
540
47%
828
July1st to 10thNight
77%
525
23%
1575
25%
525
80%
525
42%
864
July11th to 20thNight
84%
522
33%
1566
38%
522
88%
522
64%
692
July21st to endNight
87%
591
31%
1673
38%
558
89%
558
54%
802
August1st to 10thNight
88%
537
37%
1601
40%
534
90%
534
66%
691
August11th to 20thNight
79%
534
34%
1600
38%
534
80%
534
46%
821
August21st to endNight
84%
594
29%
2029
36%
594
85%
594
46%
970
September1st to 10thNight
75%
540
25%
1980
29%
540
76%
540
37%
1000
September11th to 20thNight
71%
540
26%
1980
29%
540
73%
540
32%
1062
September21st to endNight
72%
540
37%
1980
37%
540
77%
540
47%
891
October1st to 10thNight
65%
566
36%
2006
33%
566
72%
566
45%
948
October11th to 20thNight
53%
720
35%
2160
19%
720
63%
720
43%
1135
October21st to endNight
44%
792
33%
2376
20%
792
53%
792
38%
1320
November1st to 10thNight
49%
740
32%
2220
19%
740
59%
740
41%
1200
November11th to 20thNight
47%
888
31%
2408
15%
888
57%
888
43%
1330
November21st to endNight
35%
950
30%
2470
12%
950
46%
950
34%
1523
December1st to 10thNight
37%
950
32%
2470
13%
950
50%
950
38%
1480
December11th to 20thNight
35%
949
31%
2859
13%
948
44%
948
29%
1739
December21st to endNight
33%
1039
17%
4315
11%
1026
44%
1026
25%
2342

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
11%42443445%7%52%
75008
Night
10%423323447%57%
74954
TransparencyDay
31%6%11%23%22%7%
74733
Night
28%5%10%22%24%11%
74749
SeeingDay
12%7%22%28%24%7%
14043
Night
12%7%28%35%16%1
24068

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
13%7%22313346%56%
1707
11th to 20thDay
14%6%24323245%55%
1710
21st to endDay
15%5%23323346%53%
1791
February1st to 10thDay
17%6%45%423435%46%
1728
11th to 20thDay
17%6%44423445%47%
1749
21st to endDay
21%6%2332223452%
1498
March1st to 10thDay
17%5%25%43345%6%46%
1980
11th to 20thDay
16%7%2442445%5%47%
1980
21st to endDay
13%6%245%3435%5%49%
2178
April1st to 10thDay
12%425%5%35%447%50%
1980
11th to 20thDay
11%6%35%5%3445%7%47%
2045
21st to endDay
11%5%35%4245%5%7%48%
2296
May1st to 10thDay
13%5%25%5%3445%7%48%
2340
11th to 20thDay
11%5%35%6%45%5%6%6%44%
2302
21st to endDay
11%6%35%6%46%6%6%10%38%
2531
June1st to 10thDay
5%315%435%6%6%10%51%
2340
11th to 20thDay
5%3245%35%5%6%8%56%
2340
21st to endDay
5%223426%5%7%8%55%
2340
July1st to 10thDay
6%4245%37%6%7%10%45%
2340
11th to 20thDay
4212325%46%8%62%
2340
21st to endDay
3223435%7%8%11%51%
2546
August1st to 10thDay
22133245%6%9%63%
2328
11th to 20thDay
7%4245%35%5%6%10%51%
2301
21st to endDay
43245%35%6%6%12%51%
2321
September1st to 10thDay
8%32443446%8%54%
1980
11th to 20thDay
10%5%25%5%35%6%47%47%
1980
21st to endDay
7%32432346%9%57%
1980
October1st to 10thDay
5%214434447%60%
1936
11th to 20thDay
12%423222436%61%
1800
21st to endDay
14%5%2322233460%
1980
November1st to 10thDay
12%5%23313345%58%
1858
11th to 20thDay
7%423433446%61%
1767
21st to endDay
14%7%34313345%54%
1710
December1st to 10thDay
15%425%433446%50%
1710
11th to 20thDay
16%6%35%5%24345%46%
2161
21st to endDay
18%6%24423335%50%
3135
January1st to 10thNight
10%5%24423336%58%
2458
11th to 20thNight
14%5%23313335%58%
2470
21st to endNight
13%6%23323335%56%
2600
February1st to 10thNight
15%5%3432333454%
2246
11th to 20thNight
16%6%34334335%50%
2098
21st to endNight
19%6%22423335%52%
1756
March1st to 10thNight
15%5%244245%5%7%47%
1980
11th to 20thNight
13%5%34335%35%6%50%
1980
21st to endNight
11%433433346%54%
2178
April1st to 10thNight
9%42432345%9%54%
1980
11th to 20thNight
12%5%245%23447%52%
1861
21st to endNight
10%5%2432345%6%56%
1659
May1st to 10thNight
10%5%2443446%8%50%
1620
11th to 20thNight
10%424425%46%10%48%
1593
21st to endNight
8%4243245%6%9%51%
1745
June1st to 10thNight
33143345%7%9%58%
1620
11th to 20thNight
321332346%10%63%
1620
21st to endNight
22233245%6%10%60%
1620
July1st to 10thNight
3333435%5%7%10%55%
1620
11th to 20thNight
2212222349%71%
1620
21st to endNight
12133245%6%12%62%
1772
August1st to 10thNight
21121335%10%71%
1611
11th to 20thNight
43245%235%5%8%60%
1600
21st to endNight
33134245%6%10%58%
2029
September1st to 10thNight
7%32343445%7%58%
1980
11th to 20thNight
10%5%2442446%6%53%
1980
21st to endNight
5%32332335%7%64%
1980
October1st to 10thNight
5%312424446%64%
2006
11th to 20thNight
11%323322245%63%
2160
21st to endNight
16%41331223461%
2376
November1st to 10thNight
9%5%2432323463%
2220
11th to 20thNight
6%42332345%6%61%
2408
21st to endNight
15%5%24322445%53%
2470
December1st to 10thNight
13%6%23323345%56%
2470
11th to 20thNight
12%6%34433445%51%
3036
21st to endNight
16%6%24322335%54%
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
31%38%21%29%7%
1708
11th to 20thDay
33%48%23%26%6%
1710
21st to endDay
33%36%18%29%10%
1791
February1st to 10thDay
41%47%19%20%9%
1728
11th to 20thDay
41%47%20%19%9%
1759
21st to endDay
40%25%16%24%14%
1498
March1st to 10thDay
40%47%17%21%12%
1980
11th to 20thDay
40%5%8%18%22%6%
1980
21st to endDay
37%410%19%21%8%
2178
April1st to 10thDay
35%6%10%21%18%10%
1980
11th to 20thDay
37%7%10%19%20%9%
2045
21st to endDay
35%6%10%20%24%5%
2296
May1st to 10thDay
36%5%11%23%19%7%
2340
11th to 20thDay
38%7%12%22%18%2
2306
21st to endDay
39%9%14%22%14%2
2531
June1st to 10thDay
27%8%17%27%17%4
2340
11th to 20thDay
25%7%15%30%19%5%
2340
21st to endDay
24%8%12%28%24%4
2340
July1st to 10thDay
30%9%19%26%15%1
2276
11th to 20thDay
18%7%14%36%21%5%
2271
21st to endDay
21%10%17%35%16%1
2405
August1st to 10thDay
16%5%16%34%25%3
2314
11th to 20thDay
27%9%14%28%19%3
2301
21st to endDay
24%7%16%30%18%4
2321
September1st to 10thDay
28%5%11%24%23%10%
1980
11th to 20thDay
35%8%11%18%21%7%
1980
21st to endDay
24%5%10%22%27%12%
1980
October1st to 10thDay
23%6%11%23%21%16%
1936
11th to 20thDay
27%48%17%28%17%
1800
21st to endDay
30%37%18%26%16%
1980
November1st to 10thDay
30%47%23%26%10%
1858
11th to 20thDay
26%49%21%30%11%
1767
21st to endDay
34%36%21%26%10%
1710
December1st to 10thDay
36%5%8%21%24%7%
1710
11th to 20thDay
41%46%15%26%9%
2159
21st to endDay
37%45%23%22%8%
3135
January1st to 10thNight
29%38%19%29%12%
2458
11th to 20thNight
31%48%20%28%10%
2470
21st to endNight
32%35%18%28%15%
2600
February1st to 10thNight
35%48%18%22%12%
2246
11th to 20thNight
38%38%17%24%10%
2098
21st to endNight
37%47%15%20%17%
1756
March1st to 10thNight
37%5%7%17%21%13%
1980
11th to 20thNight
35%6%11%15%25%9%
1980
21st to endNight
31%5%11%20%24%8%
2178
April1st to 10thNight
28%5%12%23%19%13%
1980
11th to 20thNight
33%5%9%20%18%15%
1861
21st to endNight
29%5%11%22%27%6%
1659
May1st to 10thNight
32%7%11%21%20%9%
1620
11th to 20thNight
33%7%15%24%19%3
1594
21st to endNight
28%8%17%25%19%3
1746
June1st to 10thNight
21%7%16%31%20%5%
1620
11th to 20thNight
18%5%14%34%21%8%
1620
21st to endNight
19%8%12%28%27%6%
1620
July1st to 10thNight
24%8%16%33%17%3
1575
11th to 20thNight
11%5%13%36%28%7%
1566
21st to endNight
14%8%17%37%22%2
1673
August1st to 10thNight
10%413%37%30%5%
1601
11th to 20thNight
22%5%14%29%23%7%
1600
21st to endNight
20%6%12%34%23%5%
2029
September1st to 10thNight
25%6%10%22%26%10%
1980
11th to 20thNight
30%6%12%19%21%11%
1980
21st to endNight
19%48%23%28%17%
1980
October1st to 10thNight
21%5%10%25%21%19%
2006
11th to 20thNight
26%38%15%27%21%
2160
21st to endNight
30%3416%27%19%
2376
November1st to 10thNight
28%37%21%27%14%
2220
11th to 20thNight
25%49%20%28%14%
2408
21st to endNight
34%5%7%16%28%11%
2470
December1st to 10thNight
32%48%22%23%11%
2470
11th to 20thNight
36%36%16%27%11%
3037
21st to endNight
35%37%18%26%12%
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
21%11%34%26%7%
270
11th to 20thDay
18%17%38%20%5%2
270
21st to endDay
16%16%40%18%10%
267
February1st to 10thDay
22%17%33%23%5%
240
11th to 20thDay
23%16%42%15%3
240
21st to endDay
32%17%32%15%4
198
March1st to 10thDay
22%16%35%22%4
240
11th to 20thDay
24%16%37%18%5%1
240
21st to endDay
17%16%42%18%7%
264
April1st to 10thDay
14%20%35%23%8%
240
11th to 20thDay
18%14%35%24%9%
323
21st to endDay
16%15%36%23%8%1
556
May1st to 10thDay
14%11%34%32%8%1
603
11th to 20thDay
15%6%32%30%14%3
625
21st to endDay
12%5%28%33%17%4
679
June1st to 10thDay
7%115%39%30%8%
630
11th to 20thDay
5%117%40%28%8%
630
21st to endDay
4114%35%35%11%
630
July1st to 10thDay
6%29%33%36%15%
621
11th to 20thDay
315%32%42%17%
618
21st to endDay
3329%48%17%
684
August1st to 10thDay
317%29%49%12%
626
11th to 20thDay
8%15%33%42%11%
615
21st to endDay
415%26%43%21%
440
September1st to 10thDay
6%6%19%43%26%
270
11th to 20thDay
428%23%43%20%
270
21st to endDay
10%37%26%36%17%
270
October1st to 10thDay
3121%30%33%11%
270
11th to 20thDay
10%8%28%27%23%4
270
21st to endDay
25%10%21%24%16%3
297
November1st to 10thDay
18%7%36%22%13%5%
270
11th to 20thDay
11%10%31%32%13%4
270
21st to endDay
19%15%33%24%9%1
270
December1st to 10thDay
19%8%36%23%11%3
270
11th to 20thDay
21%12%36%24%8%
270
21st to endDay
19%15%35%24%7%
297
January1st to 10thNight
13%9%38%31%8%1
950
11th to 20thNight
17%14%31%32%5%1
950
21st to endNight
17%10%35%31%6%
1000
February1st to 10thNight
19%12%36%28%5%
806
11th to 20thNight
20%12%38%27%4
704
21st to endNight
23%13%40%21%3
572
March1st to 10thNight
17%12%37%28%5%
540
11th to 20thNight
16%10%39%29%5%
540
21st to endNight
14%12%41%29%5%
594
April1st to 10thNight
11%12%43%29%5%
540
11th to 20thNight
15%11%40%29%5%
533
21st to endNight
12%10%43%27%7%1
540
May1st to 10thNight
10%9%39%35%7%1
540
11th to 20thNight
10%6%35%35%13%1
531
21st to endNight
9%432%41%13%1
584
June1st to 10thNight
4217%49%25%3
540
11th to 20thNight
4126%52%16%1
540
21st to endNight
3116%46%29%4
540
July1st to 10thNight
4110%45%35%4
525
11th to 20thNight
39%46%38%3
522
21st to endNight
216%46%41%4
591
August1st to 10thNight
26%52%37%3
537
11th to 20thNight
6%17%46%36%5%
534
21st to endNight
315%43%42%6%
594
September1st to 10thNight
7%19%41%36%5%
540
11th to 20thNight
13%17%39%37%2
540
21st to endNight
6%116%41%33%4
540
October1st to 10thNight
7%122%39%28%2
566
11th to 20thNight
13%6%25%37%17%1
720
21st to endNight
18%8%28%32%15%
792
November1st to 10thNight
12%431%36%16%1
740
11th to 20thNight
9%9%31%37%14%
888
21st to endNight
18%10%34%28%9%
950
December1st to 10thNight
16%9%35%33%7%
950
11th to 20thNight
18%9%34%33%6%
950
21st to endNight
18%9%36%31%6%
1045
Page generated at 2024-01-19 08:28:33. Version ac07

Copyright 2024 Attilla Danko


Asteroid Hunter Observatory Clear Sky Chart |Charts Home