Bunny Foo-Foo Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bunny Foo-Foo Observatory clear sky chart from 2005-11-05 to 2017-12-20.

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%
15643
21%
48082
11%
15604
47%
15604
25%
30103

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 15thNight
22%
718
23%
2416
9%
716
39%
716
19%
1493
January16th to endNight
18%
768
23%
2496
7%
768
38%
768
20%
1568
February1st to 15thNight
21%
702
20%
2287
6%
701
39%
701
21%
1385
February16th to endNight
16%
631
25%
1907
6%
631
39%
631
22%
1178
March1st to 15thNight
23%
720
22%
2010
8%
720
38%
720
24%
1292
March16th to endNight
20%
768
21%
2082
8%
768
32%
768
24%
1399
April1st to 15thNight
24%
718
19%
1796
5%
718
33%
718
28%
1182
April16th to endNight
36%
720
20%
1800
8%
720
41%
720
30%
1186
May1st to 15thNight
34%
575
18%
1655
8%
575
41%
575
23%
1118
May16th to endNight
51%
374
17%
1497
15%
374
57%
374
23%
886
June1st to 15thNight
56%
360
19%
1440
20%
360
63%
360
26%
818
June16th to endNight
55%
360
16%
1440
15%
360
62%
360
24%
836
July1st to 15thNight
55%
340
12%
1360
14%
340
59%
340
19%
860
July16th to endNight
66%
550
16%
1581
12%
517
71%
517
34%
932
August1st to 15thNight
63%
542
17%
1612
12%
539
64%
539
29%
1017
August16th to endNight
59%
764
18%
1910
11%
764
60%
764
31%
1287
September1st to 15thNight
56%
720
25%
1800
15%
720
61%
720
33%
1189
September16th to endNight
53%
717
23%
1970
17%
717
56%
717
30%
1284
October1st to 15thNight
45%
720
23%
2160
19%
720
53%
720
26%
1391
October16th to endNight
36%
768
30%
2304
18%
768
52%
768
31%
1343
November1st to 15thNight
34%
760
24%
2415
13%
760
48%
760
26%
1448
November16th to endNight
33%
780
24%
2659
13%
780
49%
780
23%
1539
December1st to 15thNight
27%
780
19%
2730
7%
780
42%
780
18%
1732
December16th to endNight
20%
788
22%
2755
8%
788
38%
788
18%
1740

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
13%5%2442445%7%42%
48746
Night
14%5%2442445%7%44%
48264
Cloud CoverDay
13%5%25%42445%7%42%
48756
Night
14%5%2442445%7%44%
48268
TransparencyDay
39%6%11%23%16%2
48446
Night
38%5%11%23%17%3
48082
SeeingDay
17%9%26%25%14%5%
6004
Night
17%10%29%27%13%1
15648

By Month

Percentage Cloud Cover NE (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 15thDay
17%5%34415%35%7%41%
1519
16th to endDay
15%6%25%424346%42%
1728
February1st to 15thDay
15%7%25%435%45%6%41%
1575
16th to endDay
14%6%35%6%23446%41%
1566
March1st to 15thDay
15%6%25%424335%45%
1936
16th to endDay
16%6%35%5%24445%41%
2140
April1st to 15thDay
13%5%15%334447%45%
2152
16th to endDay
16%5%24324445%44%
2160
May1st to 15thDay
16%6%345%245%6%8%37%
2304
16th to endDay
14%4245%35%5%5%8%40%
2618
June1st to 15thDay
11%4245%245%6%10%41%
2520
16th to endDay
8%425%435%6%7%9%42%
2520
July1st to 15thDay
10%425%5%35%6%7%10%39%
2520
16th to endDay
6%3245%46%7%8%11%38%
2477
August1st to 15thDay
11%6%25%5%36%7%6%9%35%
2325
16th to endDay
11%4245%36%5%6%9%39%
2292
September1st to 15thDay
12%42442445%8%45%
2160
16th to endDay
13%7%24435%448%39%
1986
October1st to 15thDay
17%5%24323446%45%
1800
16th to endDay
14%414413345%50%
1920
November1st to 15thDay
15%5%13334347%47%
1770
16th to endDay
14%5%24313446%48%
1630
December1st to 15thDay
15%5%25%42445%6%43%
1560
16th to endDay
18%6%24314446%41%
1568
January1st to 15thNight
16%6%25%413346%43%
2416
16th to endNight
16%7%24424346%44%
2496
February1st to 15thNight
15%5%2341435%6%45%
2285
16th to endNight
14%7%24313347%45%
1907
March1st to 15thNight
17%42442345%6%44%
1998
16th to endNight
16%5%35%423446%42%
2082
April1st to 15thNight
13%415%42445%6%44%
1796
16th to endNight
16%5%1432445%7%45%
1800
May1st to 15thNight
16%7%35%42445%7%38%
1655
16th to endNight
13%5%14425%5%7%10%40%
1495
June1st to 15thNight
9%324335%5%7%9%44%
1440
16th to endNight
9%335%5%345%7%10%42%
1440
July1st to 15thNight
7%6%36%5%45%6%7%9%38%
1440
16th to endNight
6%224335%5%8%12%44%
1688
August1st to 15thNight
9%315%5%36%6%6%8%43%
1623
16th to endNight
10%5%26%425%6%5%9%41%
1910
September1st to 15thNight
11%5%2442446%7%45%
1800
16th to endNight
12%5%26%4245%5%7%42%
1970
October1st to 15thNight
17%5%24423436%45%
2160
16th to endNight
13%414323346%52%
2304
November1st to 15thNight
15%5%24412435%50%
2415
16th to endNight
15%41342345%7%47%
2659
December1st to 15thNight
16%6%25%5%2445%6%39%
2730
16th to endNight
17%6%25%424446%41%
2755

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 15thDay
16%5%3442435%6%42%
1519
16th to endDay
15%7%25%5%24246%42%
1728
February1st to 15thDay
15%7%245%2445%5%41%
1575
16th to endDay
15%6%25%6%2345%6%41%
1566
March1st to 15thDay
15%6%25%423346%44%
1947
16th to endDay
16%6%25%5%23446%41%
2139
April1st to 15thDay
13%5%2442445%6%45%
2152
16th to endDay
17%5%24423445%45%
2160
May1st to 15thDay
16%6%245%245%5%8%38%
2304
16th to endDay
14%425%4345%5%8%40%
2618
June1st to 15thDay
12%325%425%45%10%42%
2520
16th to endDay
9%424435%6%7%9%42%
2520
July1st to 15thDay
10%425%5%35%6%6%10%39%
2520
16th to endDay
6%415%5%46%7%8%9%40%
2477
August1st to 15thDay
11%5%25%5%45%6%7%8%36%
2325
16th to endDay
11%4245%36%6%7%8%40%
2292
September1st to 15thDay
12%42442445%8%45%
2160
16th to endDay
14%6%35%435%45%7%39%
1986
October1st to 15thDay
17%5%24313346%45%
1800
16th to endDay
13%424423245%50%
1920
November1st to 15thDay
15%5%13424337%48%
1770
16th to endDay
13%5%14322446%49%
1630
December1st to 15thDay
16%5%25%324446%44%
1560
16th to endDay
18%6%25%324346%40%
1568
January1st to 15thNight
16%6%24424446%43%
2416
16th to endNight
16%7%24423336%44%
2496
February1st to 15thNight
15%5%24424346%46%
2278
16th to endNight
14%7%24323336%46%
1907
March1st to 15thNight
17%5%2442335%6%44%
2010
16th to endNight
16%5%26%324447%41%
2082
April1st to 15thNight
14%5%146%2445%7%44%
1796
16th to endNight
17%5%1432445%7%45%
1800
May1st to 15thNight
15%6%35%42445%7%39%
1654
16th to endNight
13%5%135%245%7%9%41%
1495
June1st to 15thNight
9%4244245%8%10%43%
1440
16th to endNight
9%315%5%345%8%8%42%
1440
July1st to 15thNight
7%6%36%5%36%6%5%9%38%
1440
16th to endNight
7%324425%6%8%12%43%
1688
August1st to 15thNight
8%325%5%36%6%6%8%43%
1623
16th to endNight
10%5%36%425%5%6%9%41%
1910
September1st to 15thNight
11%5%2442445%8%45%
1800
16th to endNight
12%6%15%5%245%5%7%42%
1970
October1st to 15thNight
16%5%25%424435%45%
2160
16th to endNight
13%314313346%52%
2304
November1st to 15thNight
16%423423336%49%
2415
16th to endNight
15%413424447%47%
2659
December1st to 15thNight
16%6%25%5%245%46%39%
2730
16th to endNight
17%6%34424346%42%
2755

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 15thDay
42%412%22%14%4
1520
16th to endDay
42%310%23%14%3
1728
February1st to 15thDay
42%410%25%15%2
1577
16th to endDay
43%411%23%15%1
1566
March1st to 15thDay
41%49%23%16%3
1947
16th to endDay
44%410%19%17%3
2140
April1st to 15thDay
37%49%24%18%4
2152
16th to endDay
40%5%9%18%19%6%
2160
May1st to 15thDay
42%6%13%20%15%1
2304
16th to endDay
40%8%12%24%13%1
2622
June1st to 15thDay
35%8%13%26%14%1
2520
16th to endDay
34%9%14%21%17%2
2520
July1st to 15thDay
38%8%14%20%14%3
2371
16th to endDay
35%9%14%22%15%1
2321
August1st to 15thDay
42%8%12%21%14%
2312
16th to endDay
38%8%13%21%15%2
2292
September1st to 15thDay
35%6%13%20%20%2
2160
16th to endDay
43%5%8%22%17%2
1986
October1st to 15thDay
39%5%8%26%16%3
1800
16th to endDay
35%38%27%22%3
1920
November1st to 15thDay
36%411%24%17%4
1770
16th to endDay
35%48%28%20%3
1630
December1st to 15thDay
40%412%24%13%3
1560
16th to endDay
44%410%24%13%1
1568
January1st to 15thNight
41%410%20%18%4
2416
16th to endNight
42%48%25%17%1
2496
February1st to 15thNight
39%310%24%18%3
2287
16th to endNight
39%39%25%19%2
1907
March1st to 15thNight
39%411%26%14%2
2010
16th to endNight
42%5%10%21%17%3
2082
April1st to 15thNight
39%310%21%21%3
1796
16th to endNight
38%5%10%20%18%6%
1800
May1st to 15thNight
43%6%11%20%14%3
1655
16th to endNight
36%7%16%22%14%2
1497
June1st to 15thNight
34%7%13%27%16%1
1440
16th to endNight
35%7%15%19%18%2
1440
July1st to 15thNight
41%8%15%17%12%4
1360
16th to endNight
28%9%16%27%16%1
1581
August1st to 15thNight
35%8%14%21%18%1
1612
16th to endNight
38%8%11%23%15%2
1910
September1st to 15thNight
35%8%9%22%19%4
1800
16th to endNight
39%6%9%21%20%3
1970
October1st to 15thNight
40%5%7%23%18%3
2160
16th to endNight
32%48%26%23%4
2304
November1st to 15thNight
37%49%21%19%6%
2415
16th to endNight
35%49%24%20%4
2659
December1st to 15thNight
44%411%22%14%2
2730
16th to endNight
43%411%23%13%2
2755

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 15thDay
25%25%36%12%1
75
16th to endDay
22%32%31%12%1
96
February1st to 15thDay
28%24%37%6%2
90
16th to endDay
21%20%36%19%1
225
March1st to 15thDay
18%19%33%23%4
270
16th to endDay
20%13%39%19%42
288
April1st to 15thDay
18%15%29%24%11%
270
16th to endDay
20%10%29%23%11%4
270
May1st to 15thDay
28%16%26%14%11%2
288
16th to endDay
20%425%25%18%5%
331
June1st to 15thDay
14%7%25%24%21%6%
315
16th to endDay
12%5%30%32%14%3
315
July1st to 15thDay
16%121%34%20%4
305
16th to endDay
7%115%39%24%11%
326
August1st to 15thDay
15%118%30%25%8%
313
16th to endDay
11%13%36%23%14%
332
September1st to 15thDay
13%5%23%25%14%17%
315
16th to endDay
21%417%27%17%11%
314
October1st to 15thDay
21%421%24%21%6%
315
16th to endDay
13%13%30%24%14%3
336
November1st to 15thDay
21%10%26%25%13%3
293
16th to endDay
15%19%34%17%11%1
160
December1st to 15thDay
20%24%23%16%13%2
90
16th to endDay
37%11%27%22%1
72
January1st to 15thNight
20%18%34%21%4
720
16th to endNight
22%17%37%20%1
768
February1st to 15thNight
20%17%36%24%1
704
16th to endNight
20%22%36%18%1
631
March1st to 15thNight
21%14%37%23%3
720
16th to endNight
19%13%42%17%5%
768
April1st to 15thNight
17%17%38%22%4
718
16th to endNight
20%8%30%27%11%
720
May1st to 15thNight
18%9%33%26%10%
575
16th to endNight
15%6%22%37%17%1
375
June1st to 15thNight
9%324%39%21%1
360
16th to endNight
10%222%46%17%
360
July1st to 15thNight
10%222%38%25%
340
16th to endNight
8%17%39%29%4
550
August1st to 15thNight
11%14%44%26%2
542
16th to endNight
14%115%35%29%3
764
September1st to 15thNight
15%217%34%27%2
720
16th to endNight
16%320%30%26%3
717
October1st to 15thNight
19%7%20%28%20%4
720
16th to endNight
16%13%31%23%14%1
768
November1st to 15thNight
17%11%31%24%12%2
760
16th to endNight
17%16%28%26%9%
780
December1st to 15thNight
20%14%32%22%9%
780
16th to endNight
21%15%38%21%2
788
Page generated at 2017-12-21 07:04:53. Version ac04

Copyright 2017 A. Danko


Bunny Foo-Foo Observatory Clear Sky Chart |Charts Home