Lamoine Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lamoine Observatory clear sky chart from 2005-11-05 to 2017-09-23.

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
23%
14876
15%
46874
6%
14839
33%
14839
15%
32349

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
12%
720
16%
2506
4%
716
27%
716
10%
1682
January16th to endNight
9%
768
15%
2643
2%
768
25%
768
9%
1809
February1st to 15thNight
10%
704
12%
2286
1%
701
23%
701
10%
1630
February16th to endNight
15%
631
16%
1898
3%
631
31%
631
13%
1323
March1st to 15thNight
15%
720
16%
2080
5%
720
27%
720
13%
1496
March16th to endNight
19%
768
18%
2112
6%
768
29%
768
17%
1476
April1st to 15thNight
17%
662
16%
1770
5%
662
25%
662
16%
1283
April16th to endNight
23%
540
13%
1620
3%
540
31%
540
16%
1150
May1st to 15thNight
24%
540
12%
1620
6%
540
31%
540
14%
1177
May16th to endNight
24%
483
11%
1530
7%
482
31%
482
13%
1130
June1st to 15thNight
28%
360
8%
1260
7%
360
33%
360
11%
964
June16th to endNight
32%
360
9%
1260
7%
360
37%
360
13%
897
July1st to 15thNight
38%
340
9%
1288
10%
340
42%
340
15%
855
July16th to endNight
34%
412
10%
1451
8%
387
41%
387
13%
1038
August1st to 15thNight
42%
539
11%
1608
8%
535
45%
535
18%
1135
August16th to endNight
44%
573
18%
1719
9%
573
50%
573
24%
1111
September1st to 15thNight
40%
706
16%
1918
8%
706
46%
706
29%
1245
September16th to endNight
39%
689
25%
1902
12%
689
49%
689
31%
1146
October1st to 15thNight
29%
660
20%
1910
9%
660
39%
660
20%
1276
October16th to endNight
19%
704
17%
2222
5%
704
33%
704
17%
1491
November1st to 15thNight
27%
700
18%
2277
11%
700
37%
700
17%
1503
November16th to endNight
18%
747
16%
2497
4%
747
32%
747
12%
1687
December1st to 15thNight
12%
750
13%
2617
3%
750
25%
750
10%
1841
December16th to endNight
10%
800
14%
2880
2%
800
26%
800
10%
2004

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
19%7%25%424447%37%
48026
Night
20%8%35%424446%36%
47048
TransparencyDay
46%6%12%21%12%1
47719
Night
48%5%11%20%11%1
46874
SeeingDay
22%20%28%19%7%1
6523
Night
21%25%25%19%7%
14876

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
15%8%35%5%15%348%38%
1429
16th to endDay
16%9%35%423348%37%
1578
February1st to 15thDay
16%10%26%5%35%5%6%6%32%
1575
16th to endDay
13%9%46%5%25%5%46%33%
1574
March1st to 15thDay
20%8%36%434346%34%
1868
16th to endDay
17%7%345%33346%39%
2112
April1st to 15thDay
21%8%35%423336%37%
2178
16th to endDay
20%7%35%433346%37%
2340
May1st to 15thDay
24%8%35%5%24346%31%
2332
16th to endDay
23%7%3442335%7%33%
2592
June1st to 15thDay
24%9%36%5%24447%27%
2700
16th to endDay
23%6%25%435%446%32%
2700
July1st to 15thDay
17%424425%5%5%8%39%
2591
16th to endDay
15%7%24435%5%6%8%36%
2606
August1st to 15thDay
16%5%25%42435%7%40%
2340
16th to endDay
11%4245%235%5%9%45%
2483
September1st to 15thDay
12%5%13435%447%47%
2040
16th to endDay
16%5%23322337%48%
1895
October1st to 15thDay
19%5%24324446%41%
1719
16th to endDay
21%6%24424445%40%
1647
November1st to 15thDay
23%5%24423346%39%
1581
16th to endDay
20%7%26%423445%38%
1461
December1st to 15thDay
24%9%24334346%34%
1341
16th to endDay
24%10%26%323335%33%
1344
January1st to 15thNight
17%8%35%424447%37%
2506
16th to endNight
15%10%36%5%2445%8%32%
2643
February1st to 15thNight
15%9%36%6%35%45%6%33%
2285
16th to endNight
16%9%45%5%24446%37%
1898
March1st to 15thNight
20%10%45%42335%5%34%
2068
16th to endNight
17%7%36%5%23446%38%
2112
April1st to 15thNight
22%9%345%43446%31%
1770
16th to endNight
23%8%36%423347%33%
1620
May1st to 15thNight
24%7%25%5%25%35%6%31%
1620
16th to endNight
24%9%46%434345%29%
1528
June1st to 15thNight
28%9%3443446%6%24%
1260
16th to endNight
23%8%35%434347%31%
1260
July1st to 15thNight
20%6%25%5%245%6%6%33%
1366
16th to endNight
21%8%36%5%3445%7%29%
1550
August1st to 15thNight
17%7%25%425%6%6%8%33%
1620
16th to endNight
15%5%24433449%41%
1719
September1st to 15thNight
16%423424447%44%
1918
16th to endNight
14%423313346%50%
1902
October1st to 15thNight
21%6%23423435%41%
1910
16th to endNight
21%7%35%422436%39%
2222
November1st to 15thNight
19%6%24424445%39%
2277
16th to endNight
19%8%34324446%37%
2497
December1st to 15thNight
24%8%25%423336%34%
2617
16th to endNight
24%9%34423336%34%
2880

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
46%7%13%20%11%1
1430
16th to endDay
47%413%24%8%1
1578
February1st to 15thDay
52%5%14%18%8%
1578
16th to endDay
49%5%13%19%10%1
1574
March1st to 15thDay
51%5%12%17%11%1
1879
16th to endDay
45%5%9%17%17%3
2112
April1st to 15thDay
47%49%20%15%2
2178
16th to endDay
46%6%10%18%14%4
2340
May1st to 15thDay
53%5%9%17%12%2
2332
16th to endDay
51%6%10%21%8%1
2596
June1st to 15thDay
56%6%10%17%7%1
2700
16th to endDay
51%6%10%17%12%1
2700
July1st to 15thDay
41%8%15%22%11%
2441
16th to endDay
43%9%15%22%8%
2443
August1st to 15thDay
42%7%14%26%9%
2327
16th to endDay
34%6%15%26%17%
2483
September1st to 15thDay
35%6%12%25%17%2
2040
16th to endDay
36%49%28%19%1
1895
October1st to 15thDay
42%5%10%24%14%1
1719
16th to endDay
45%413%24%11%
1647
November1st to 15thDay
46%5%11%21%13%
1581
16th to endDay
49%6%13%18%12%
1461
December1st to 15thDay
52%413%21%6%
1341
16th to endDay
54%5%10%20%10%
1344
January1st to 15thNight
47%6%14%22%8%
2506
16th to endNight
50%5%12%22%8%
2643
February1st to 15thNight
51%6%13%18%8%
2286
16th to endNight
49%5%11%19%12%1
1898
March1st to 15thNight
53%39%18%12%2
2080
16th to endNight
46%5%9%18%17%2
2112
April1st to 15thNight
52%49%15%15%2
1770
16th to endNight
51%49%16%14%3
1620
May1st to 15thNight
52%6%8%16%14%1
1620
16th to endNight
56%5%8%19%8%
1530
June1st to 15thNight
58%7%9%16%5%1
1260
16th to endNight
53%5%11%19%9%
1260
July1st to 15thNight
48%6%14%19%10%
1288
16th to endNight
53%7%11%18%7%1
1451
August1st to 15thNight
47%8%12%22%8%
1608
16th to endNight
40%6%13%22%15%
1719
September1st to 15thNight
38%5%12%26%15%1
1918
16th to endNight
34%310%30%20%
1902
October1st to 15thNight
45%49%23%15%1
1910
16th to endNight
47%410%24%12%
2222
November1st to 15thNight
45%5%13%21%13%
2277
16th to endNight
47%6%12%20%11%1
2497
December1st to 15thNight
53%412%21%7%
2617
16th to endNight
52%412%19%10%
2880

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
16%33%38%11%
60
16th to endDay
19%31%34%12%
106
February1st to 15thDay
21%33%31%11%2
236
16th to endDay
18%27%34%16%2
238
March1st to 15thDay
24%31%28%12%2
270
16th to endDay
23%30%27%11%5%1
288
April1st to 15thDay
26%25%28%13%41
270
16th to endDay
24%20%35%10%6%2
270
May1st to 15thDay
29%24%26%14%41
288
16th to endDay
25%21%27%16%7%
405
June1st to 15thDay
24%15%28%23%7%
495
16th to endDay
27%16%24%20%9%1
495
July1st to 15thDay
21%11%29%21%14%
375
16th to endDay
17%12%28%28%11%
326
August1st to 15thDay
18%13%24%28%13%1
313
16th to endDay
16%10%25%30%13%4
332
September1st to 15thDay
20%9%28%30%9%2
315
16th to endDay
17%10%31%22%13%5%
283
October1st to 15thDay
20%20%23%22%11%2
238
16th to endDay
25%20%33%15%4
240
November1st to 15thDay
21%28%20%20%6%2
235
16th to endDay
22%32%23%14%5%1
240
December1st to 15thDay
26%26%27%17%2
141
16th to endDay
37%25%28%9%
64
January1st to 15thNight
18%39%26%13%2
720
16th to endNight
19%37%29%10%2
768
February1st to 15thNight
20%37%28%11%2
704
16th to endNight
20%33%27%14%3
631
March1st to 15thNight
23%31%25%16%3
720
16th to endNight
18%30%28%16%5%
768
April1st to 15thNight
24%26%29%15%3
662
16th to endNight
23%22%25%20%6%1
540
May1st to 15thNight
23%20%27%20%6%1
540
16th to endNight
24%21%22%22%7%
483
June1st to 15thNight
27%20%19%23%8%
360
16th to endNight
26%17%18%26%9%1
360
July1st to 15thNight
23%13%19%31%11%
340
16th to endNight
20%17%18%30%12%
412
August1st to 15thNight
22%11%16%33%15%1
539
16th to endNight
17%10%19%32%18%1
573
September1st to 15thNight
17%10%26%29%14%2
706
16th to endNight
17%12%25%25%15%3
689
October1st to 15thNight
23%17%24%21%10%1
660
16th to endNight
22%23%31%16%6%
704
November1st to 15thNight
18%26%23%22%8%1
700
16th to endNight
19%32%25%14%7%
747
December1st to 15thNight
27%32%24%12%2
750
16th to endNight
27%32%26%11%1
800
Page generated at 2017-09-24 09:15:56. Version ac04

Copyright 2017 A. Danko


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