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Long Sault Conservation Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Long Sault Conservation Area clear sky chart from 2005-11-05 to 2017-09-10.

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
35%
14754
14%
46818
9%
14720
41%
14720
19%
32450

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
15%
719
9%
2506
3%
716
22%
716
9%
1971
January16th to endNight
21%
768
12%
2502
5%
768
29%
768
11%
1933
February1st to 15thNight
16%
702
10%
2287
3%
701
25%
701
11%
1761
February16th to endNight
23%
631
13%
2021
5%
631
34%
631
16%
1461
March1st to 15thNight
24%
720
14%
1985
6%
720
31%
720
17%
1482
March16th to endNight
31%
768
20%
2112
9%
768
40%
768
26%
1403
April1st to 15thNight
30%
718
16%
1798
6%
718
36%
718
23%
1316
April16th to endNight
37%
588
19%
1668
8%
588
44%
588
27%
1093
May1st to 15thNight
47%
453
15%
1533
12%
453
53%
453
21%
1008
May16th to endNight
52%
374
17%
1497
18%
374
60%
374
26%
827
June1st to 15thNight
46%
360
11%
1440
11%
360
54%
360
20%
892
June16th to endNight
54%
360
11%
1440
16%
360
58%
360
23%
839
July1st to 15thNight
65%
340
16%
1360
24%
340
69%
340
32%
698
July16th to endNight
63%
443
16%
1480
18%
416
66%
416
31%
838
August1st to 15thNight
67%
539
17%
1609
13%
536
69%
536
34%
946
August16th to endNight
62%
642
22%
1788
13%
642
65%
642
36%
1061
September1st to 15thNight
52%
700
19%
1750
9%
700
57%
700
34%
1152
September16th to endNight
54%
657
20%
1834
14%
657
58%
657
30%
1166
October1st to 15thNight
38%
660
16%
1980
13%
660
44%
660
22%
1367
October16th to endNight
27%
704
12%
2112
8%
704
33%
704
14%
1594
November1st to 15thNight
36%
700
18%
2388
15%
700
42%
700
19%
1611
November16th to endNight
25%
720
10%
2520
7%
720
31%
720
12%
1899
December1st to 15thNight
16%
720
6%
2520
3%
720
21%
720
9%
1977
December16th to endNight
15%
768
7%
2688
2%
768
20%
768
8%
2155

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
15%9%36%5%35%45%7%33%
47814
Night
15%8%36%5%3445%6%34%
46994
Cloud CoverDay
16%8%36%5%35%45%7%33%
47824
Night
15%8%36%5%25%45%6%35%
46999
TransparencyDay
48%7%13%19%10%1
47508
Night
48%6%12%20%11%1
46818
SeeingDay
18%6%25%26%15%6%
5348
Night
19%7%28%29%12%1
14758

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
19%13%5%9%6%24346%24%
1432
16th to endDay
13%15%6%11%8%25%44420%
1719
February1st to 15thDay
13%15%6%12%7%45%34421%
1575
16th to endDay
17%13%5%8%7%34335%25%
1452
March1st to 15thDay
15%12%38%7%35%445%29%
1963
16th to endDay
17%9%45%424345%38%
2112
April1st to 15thDay
21%10%45%43435%6%30%
2149
16th to endDay
19%8%24424345%39%
2302
May1st to 15thDay
16%6%36%6%3445%7%34%
2417
16th to endDay
13%5%35%5%35%45%7%39%
2618
June1st to 15thDay
18%6%35%5%245%5%7%34%
2520
16th to endDay
14%5%25%5%36%5%5%9%36%
2520
July1st to 15thDay
9%5%245%35%5%7%9%40%
2520
16th to endDay
9%5%36%6%36%6%6%9%36%
2586
August1st to 15thDay
9%6%26%6%46%5%5%8%39%
2340
16th to endDay
12%6%24425%5%6%10%39%
2402
September1st to 15thDay
16%5%245%36%5%5%7%38%
2098
16th to endDay
14%7%26%42345%6%41%
1793
October1st to 15thDay
20%8%35%5%345%45%32%
1650
16th to endDay
25%11%48%5%33345%25%
1760
November1st to 15thDay
16%10%46%5%35%45%5%32%
1470
16th to endDay
18%14%47%6%4445%5%24%
1440
December1st to 15thDay
18%14%7%10%6%25%45%5%20%
1440
16th to endDay
20%14%6%9%5%36%45%5%17%
1536
January1st to 15thNight
20%13%6%8%7%3434422%
2506
16th to endNight
14%14%5%10%6%45%445%24%
2502
February1st to 15thNight
13%14%6%9%7%35%445%24%
2285
16th to endNight
15%10%48%7%34445%30%
2021
March1st to 15thNight
18%10%5%7%6%2433432%
1973
16th to endNight
14%6%45%424335%43%
2112
April1st to 15thNight
20%8%345%24446%35%
1798
16th to endNight
13%8%25%324445%43%
1668
May1st to 15thNight
15%6%25%5%45%5%5%7%37%
1533
16th to endNight
12%4243235%6%8%47%
1495
June1st to 15thNight
13%5%246%35%5%5%8%38%
1440
16th to endNight
10%5%25%5%25%5%6%9%42%
1440
July1st to 15thNight
5%424325%46%8%52%
1440
16th to endNight
8%3144245%7%9%47%
1581
August1st to 15thNight
7%4145%35%46%8%49%
1620
16th to endNight
6%5%2443445%7%51%
1788
September1st to 15thNight
14%5%25%42345%6%46%
1750
16th to endNight
14%5%25%423446%46%
1834
October1st to 15thNight
18%7%25%5%3435%7%36%
1980
16th to endNight
22%8%36%5%36%45%6%27%
2112
November1st to 15thNight
17%8%35%5%24447%35%
2388
16th to endNight
21%10%47%6%35%5%5%6%24%
2520
December1st to 15thNight
19%14%5%8%6%25%446%22%
2520
16th to endNight
21%13%5%9%6%35%45%6%18%
2688

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
18%15%48%6%24336%25%
1432
16th to endDay
13%16%5%11%8%35%44421%
1719
February1st to 15thDay
13%15%5%11%8%34445%21%
1575
16th to endDay
18%13%5%8%6%3434426%
1452
March1st to 15thDay
16%10%47%6%45%446%29%
1974
16th to endDay
17%9%35%42444439%
2111
April1st to 15thDay
21%10%46%42445%6%30%
2149
16th to endDay
19%7%345%33435%39%
2302
May1st to 15thDay
17%6%25%6%25%45%6%34%
2417
16th to endDay
13%5%35%5%345%5%8%39%
2618
June1st to 15thDay
18%5%35%425%5%5%7%34%
2520
16th to endDay
14%6%245%35%5%6%9%36%
2520
July1st to 15thDay
10%424435%5%7%10%41%
2520
16th to endDay
9%5%25%6%46%6%6%9%36%
2586
August1st to 15thDay
9%6%26%6%35%5%5%8%40%
2340
16th to endDay
12%5%243345%7%9%40%
2402
September1st to 15thDay
16%5%235%45%6%5%6%39%
2098
16th to endDay
14%6%25%5%2445%7%41%
1793
October1st to 15thDay
20%7%26%5%345%46%32%
1650
16th to endDay
25%10%47%5%33445%25%
1760
November1st to 15thDay
16%9%46%425%5%5%6%32%
1470
16th to endDay
19%13%47%7%34446%24%
1440
December1st to 15thDay
19%13%7%9%6%245%5%5%21%
1440
16th to endDay
20%14%5%9%6%26%45%5%19%
1536
January1st to 15thNight
20%13%6%8%7%3434423%
2506
16th to endNight
14%14%5%8%6%36%445%24%
2502
February1st to 15thNight
13%14%5%9%6%35%44426%
2278
16th to endNight
15%9%48%7%35%445%30%
2021
March1st to 15thNight
19%10%47%6%2433432%
1985
16th to endNight
14%6%35%425%335%43%
2112
April1st to 15thNight
20%7%345%24447%35%
1798
16th to endNight
13%7%35%424445%43%
1668
May1st to 15thNight
15%5%25%5%36%45%7%38%
1533
16th to endNight
11%42442346%8%47%
1495
June1st to 15thNight
14%4346%36%5%6%7%39%
1440
16th to endNight
11%5%24425%5%6%8%42%
1440
July1st to 15thNight
5%3243245%5%9%53%
1440
16th to endNight
8%224425%47%9%47%
1581
August1st to 15thNight
8%314435%5%5%8%49%
1620
16th to endNight
7%324424447%52%
1788
September1st to 15thNight
14%5%2442345%6%47%
1750
16th to endNight
14%6%24323346%46%
1834
October1st to 15thNight
18%6%35%5%24446%37%
1980
16th to endNight
22%7%36%5%35%45%6%28%
2112
November1st to 15thNight
17%8%35%42445%7%36%
2388
16th to endNight
21%10%46%5%35%5%5%6%24%
2520
December1st to 15thNight
20%14%5%7%6%35%45%6%22%
2520
16th to endNight
21%12%5%8%6%45%5%5%6%18%
2688

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
59%6%13%13%6%
1433
16th to endDay
65%7%9%11%6%
1719
February1st to 15thDay
64%5%9%14%3
1577
16th to endDay
58%6%10%15%8%
1452
March1st to 15thDay
55%5%15%16%7%
1974
16th to endDay
47%49%18%17%2
2112
April1st to 15thDay
53%410%18%11%1
2149
16th to endDay
46%5%9%21%15%1
2302
May1st to 15thDay
47%6%11%19%13%1
2417
16th to endDay
41%7%14%22%12%1
2622
June1st to 15thDay
46%7%13%21%11%
2520
16th to endDay
40%8%16%20%12%
2520
July1st to 15thDay
33%7%14%25%16%1
2371
16th to endDay
40%9%15%23%9%1
2424
August1st to 15thDay
39%9%15%21%12%1
2327
16th to endDay
36%7%16%26%11%1
2402
September1st to 15thDay
41%7%15%25%10%
2098
16th to endDay
41%7%12%26%10%
1793
October1st to 15thDay
51%6%12%19%9%1
1650
16th to endDay
59%6%14%13%4
1760
November1st to 15thDay
50%7%15%16%8%1
1470
16th to endDay
59%7%12%13%5%
1440
December1st to 15thDay
62%7%15%11%2
1440
16th to endDay
65%8%10%12%2
1536
January1st to 15thNight
64%5%10%13%41
2506
16th to endNight
60%6%9%15%6%
2502
February1st to 15thNight
60%6%10%16%5%
2287
16th to endNight
54%414%18%7%
2021
March1st to 15thNight
55%412%19%7%
1985
16th to endNight
43%410%22%17%2
2112
April1st to 15thNight
49%5%9%18%15%1
1798
16th to endNight
40%5%12%19%19%2
1668
May1st to 15thNight
43%7%12%19%15%2
1533
16th to endNight
32%7%14%25%16%2
1497
June1st to 15thNight
40%8%11%22%15%1
1440
16th to endNight
37%6%13%24%15%1
1440
July1st to 15thNight
26%7%13%28%23%1
1360
16th to endNight
31%7%13%28%16%2
1480
August1st to 15thNight
29%8%19%27%13%1
1609
16th to endNight
31%6%14%30%15%1
1788
September1st to 15thNight
37%5%14%27%13%1
1750
16th to endNight
37%5%11%30%13%
1834
October1st to 15thNight
46%6%13%20%12%
1980
16th to endNight
55%7%12%15%7%
2112
November1st to 15thNight
47%6%14%18%12%1
2388
16th to endNight
57%7%14%14%5%
2520
December1st to 15thNight
61%8%14%12%2
2520
16th to endNight
64%8%12%10%4
2688

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
23%23%28%15%8%1
60
16th to endDay
35%11%29%18%4
95
February1st to 15thDay
21%31%38%8%
90
16th to endDay
26%17%33%19%3
111
March1st to 15thDay
24%13%31%24%5%
270
16th to endDay
23%7%34%22%8%2
288
April1st to 15thDay
22%10%32%24%9%1
270
16th to endDay
21%7%30%23%14%4
270
May1st to 15thDay
23%423%27%14%7%
288
16th to endDay
15%5%27%27%19%4
331
June1st to 15thDay
20%5%23%31%17%1
315
16th to endDay
17%123%33%18%5%
315
July1st to 15thDay
14%112%35%26%8%
305
16th to endDay
9%125%30%22%9%
326
August1st to 15thDay
10%116%33%23%12%
313
16th to endDay
15%315%24%23%17%
332
September1st to 15thDay
13%321%24%22%14%
294
16th to endDay
18%418%30%18%11%
254
October1st to 15thDay
18%5%29%25%16%5%
255
16th to endDay
27%12%28%25%5%
272
November1st to 15thDay
13%8%29%35%11%1
110
16th to endDay
26%15%25%21%11%
60
December1st to 15thDay
13%25%38%13%8%1
60
16th to endDay
29%18%40%10%
64
January1st to 15thNight
26%15%36%16%5%
720
16th to endNight
21%9%35%26%5%
768
February1st to 15thNight
20%12%40%21%3
704
16th to endNight
19%11%37%25%5%
631
March1st to 15thNight
24%12%32%26%3
720
16th to endNight
17%8%34%26%11%1
768
April1st to 15thNight
22%9%32%29%5%
718
16th to endNight
17%6%32%29%12%1
588
May1st to 15thNight
18%423%35%15%3
453
16th to endNight
13%423%35%22%
375
June1st to 15thNight
15%226%38%16%
360
16th to endNight
11%222%42%20%
360
July1st to 15thNight
6%219%48%21%2
340
16th to endNight
9%116%43%26%2
443
August1st to 15thNight
9%113%42%28%3
539
16th to endNight
9%117%37%29%3
642
September1st to 15thNight
17%319%32%24%4
700
16th to endNight
17%5%17%27%26%5%
657
October1st to 15thNight
23%5%25%27%16%2
660
16th to endNight
26%8%30%26%6%
704
November1st to 15thNight
21%9%27%28%12%1
700
16th to endNight
25%11%28%24%8%
720
December1st to 15thNight
29%11%35%19%3
720
16th to endNight
26%10%38%21%2
768
Page generated at 2017-09-11 19:35:29. Version ac04

Copyright 2017 A. Danko


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