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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 2018-03-11.

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%
15482
14%
49157
9%
15448
41%
15448
19%
34078

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%
779
9%
2716
3%
776
23%
776
10%
2113
January16th to endNight
21%
832
11%
2710
4%
832
29%
832
11%
2095
February1st to 15thNight
15%
762
11%
2482
3%
761
25%
761
11%
1906
February16th to endNight
23%
683
13%
2188
5%
683
33%
683
16%
1580
March1st to 15thNight
23%
764
13%
2106
6%
764
30%
764
17%
1569
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
53%
720
20%
1800
10%
720
57%
720
35%
1175
September16th to endNight
56%
717
23%
2001
17%
717
59%
717
32%
1257
October1st to 15thNight
39%
720
15%
2160
13%
720
44%
720
22%
1488
October16th to endNight
28%
768
14%
2304
9%
768
35%
768
15%
1715
November1st to 15thNight
35%
760
17%
2593
14%
760
41%
760
18%
1768
November16th to endNight
25%
780
10%
2730
6%
780
31%
780
12%
2042
December1st to 15thNight
17%
780
7%
2730
3%
780
22%
780
9%
2133
December16th to endNight
15%
832
7%
2912
2%
832
21%
832
8%
2316

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%6%33%
49474
Night
15%9%36%5%3445%6%34%
49333
Cloud CoverDay
16%8%36%5%35%45%6%33%
49484
Night
15%8%36%5%35%45%6%35%
49338
TransparencyDay
48%7%13%19%10%1
49168
Night
48%6%12%19%11%1
49157
SeeingDay
19%7%25%25%15%6%
5885
Night
19%8%29%28%12%1
15486

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%48%7%24346%24%
1552
16th to endDay
14%15%6%11%8%35%44420%
1862
February1st to 15thDay
14%15%7%11%7%45%345%21%
1710
16th to endDay
18%13%48%7%34335%25%
1571
March1st to 15thDay
15%12%38%7%35%345%29%
2078
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
15%5%245%36%5%5%7%39%
2160
16th to endDay
13%7%25%42345%6%43%
1956
October1st to 15thDay
21%8%35%5%34445%32%
1800
16th to endDay
24%10%48%5%33345%25%
1920
November1st to 15thDay
16%10%46%5%35%45%5%31%
1595
16th to endDay
18%13%47%6%3445%5%25%
1560
December1st to 15thDay
17%15%7%10%6%25%45%5%21%
1560
16th to endDay
20%14%6%9%6%35%45%5%19%
1664
January1st to 15thNight
20%13%6%8%7%3434423%
2716
16th to endNight
14%14%5%9%6%45%45%5%24%
2710
February1st to 15thNight
13%14%5%9%7%35%445%24%
2480
16th to endNight
15%10%48%7%3445%5%30%
2188
March1st to 15thNight
18%10%5%7%7%2433433%
2094
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
13%5%25%42345%6%47%
1800
16th to endNight
13%5%25%423346%48%
2001
October1st to 15thNight
18%6%25%5%3435%6%37%
2160
16th to endNight
21%8%36%5%35%45%6%28%
2304
November1st to 15thNight
18%9%35%5%24447%34%
2593
16th to endNight
21%9%47%6%35%5%46%24%
2730
December1st to 15thNight
18%14%5%8%6%25%446%22%
2730
16th to endNight
20%13%5%8%6%35%446%19%
2912

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%14%39%7%24336%25%
1552
16th to endDay
13%15%6%11%7%35%44421%
1862
February1st to 15thDay
14%15%5%11%8%34445%21%
1710
16th to endDay
18%13%48%6%34445%26%
1571
March1st to 15thDay
16%10%48%6%45%445%29%
2089
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
15%5%235%35%6%46%40%
2160
16th to endDay
13%5%25%42445%7%43%
1956
October1st to 15thDay
21%7%26%5%345%45%32%
1800
16th to endDay
24%10%47%5%33445%26%
1920
November1st to 15thDay
17%10%46%5%25%5%5%6%30%
1595
16th to endDay
19%12%46%7%34446%25%
1560
December1st to 15thDay
18%13%7%9%6%2445%5%21%
1560
16th to endDay
20%14%5%9%6%25%445%20%
1664
January1st to 15thNight
20%13%6%7%7%3434423%
2716
16th to endNight
14%14%6%8%6%36%45%5%24%
2710
February1st to 15thNight
13%14%5%9%7%35%44425%
2473
16th to endNight
16%9%48%7%35%445%30%
2188
March1st to 15thNight
19%10%47%6%2433432%
2106
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
13%5%2342345%5%48%
1800
16th to endNight
13%5%24323346%48%
2001
October1st to 15thNight
18%6%35%5%24446%37%
2160
16th to endNight
21%7%36%5%35%45%6%29%
2304
November1st to 15thNight
18%8%35%434347%35%
2593
16th to endNight
21%9%46%5%35%5%5%7%25%
2730
December1st to 15thNight
19%14%5%7%6%35%45%6%22%
2730
16th to endNight
20%13%5%7%6%45%5%5%6%20%
2912

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
60%6%12%13%7%
1553
16th to endDay
65%6%9%11%6%
1862
February1st to 15thDay
65%5%9%15%4
1712
16th to endDay
58%6%10%14%8%1
1571
March1st to 15thDay
55%5%14%15%8%
2089
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
40%7%15%25%11%
2160
16th to endDay
39%7%13%27%11%
1956
October1st to 15thDay
51%6%11%19%9%1
1800
16th to endDay
58%6%14%13%41
1920
November1st to 15thDay
51%7%14%16%8%1
1595
16th to endDay
58%7%13%13%5%
1560
December1st to 15thDay
62%7%15%11%2
1560
16th to endDay
64%7%10%12%4
1664
January1st to 15thNight
63%5%10%13%6%1
2716
16th to endNight
60%6%10%15%6%
2710
February1st to 15thNight
60%6%10%16%5%
2482
16th to endNight
54%413%18%7%
2188
March1st to 15thNight
55%411%19%7%1
2106
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
36%5%14%27%14%1
1800
16th to endNight
36%5%11%30%15%
2001
October1st to 15thNight
46%6%12%20%12%
2160
16th to endNight
53%7%13%16%7%
2304
November1st to 15thNight
48%6%13%18%11%1
2593
16th to endNight
56%8%15%14%5%
2730
December1st to 15thNight
60%8%14%12%3
2730
16th to endNight
63%8%11%10%5%
2912

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%22%30%16%6%1
90
16th to endDay
32%13%32%18%3
142
February1st to 15thDay
23%31%37%6%
135
16th to endDay
28%17%34%16%2
152
March1st to 15thDay
23%13%33%24%5%
312
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
12%319%24%24%15%
315
16th to endDay
15%416%26%20%16%
314
October1st to 15thDay
22%426%25%15%5%
315
16th to endDay
25%14%27%23%7%
336
November1st to 15thDay
19%9%28%29%11%1
145
16th to endDay
24%17%32%16%8%
90
December1st to 15thDay
13%25%34%17%7%1
90
16th to endDay
27%17%39%15%
96
January1st to 15thNight
26%14%37%16%5%
780
16th to endNight
21%9%36%26%5%
832
February1st to 15thNight
20%12%41%20%3
764
16th to endNight
19%11%39%24%5%
683
March1st to 15thNight
24%12%32%27%3
764
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
16%218%31%25%5%
720
16th to endNight
16%5%16%27%27%7%
717
October1st to 15thNight
23%5%25%27%16%2
720
16th to endNight
25%9%29%27%6%
768
November1st to 15thNight
22%9%26%27%11%1
760
16th to endNight
24%12%29%23%8%
780
December1st to 15thNight
29%11%35%19%3
780
16th to endNight
26%10%38%20%2
832
Page generated at 2018-03-12 13:28:01. Version ac04

Copyright 2018 A. Danko


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