Centre écologique de Port-au-Saumon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Centre écologique de Port-au-Saumon clear sky chart from 2005-11-05 to 2018-02-14.

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
27%
15253
11%
48848
6%
15221
33%
15221
13%
36254

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
14%
798
8%
2794
3%
794
21%
794
8%
2228
January16th to endNight
25%
832
10%
2912
5%
832
33%
832
10%
2204
February1st to 15thNight
18%
760
10%
2570
4%
757
26%
757
11%
1921
February16th to endNight
20%
631
10%
1896
4%
631
28%
631
11%
1493
March1st to 15thNight
21%
720
13%
2130
8%
720
27%
720
14%
1602
March16th to endNight
27%
768
17%
2064
8%
768
34%
768
18%
1500
April1st to 15thNight
21%
676
14%
1754
6%
676
26%
676
14%
1368
April16th to endNight
25%
540
16%
1620
7%
540
33%
540
15%
1137
May1st to 15thNight
28%
479
11%
1559
8%
479
34%
479
13%
1131
May16th to endNight
25%
375
10%
1359
4%
374
36%
374
11%
1014
June1st to 15thNight
29%
360
6%
1260
4%
360
32%
360
13%
897
June16th to endNight
33%
360
5%
1260
2%
360
37%
360
14%
899
July1st to 15thNight
39%
340
7%
1207
7%
340
42%
340
17%
832
July16th to endNight
44%
376
8%
1418
10%
354
52%
354
15%
957
August1st to 15thNight
48%
437
9%
1508
9%
435
52%
435
16%
1051
August16th to endNight
46%
581
13%
1727
8%
581
49%
581
21%
1173
September1st to 15thNight
36%
720
10%
1875
4%
720
39%
720
22%
1349
September16th to endNight
40%
717
17%
1980
11%
717
44%
717
26%
1309
October1st to 15thNight
31%
720
15%
2085
7%
720
38%
720
20%
1451
October16th to endNight
24%
768
10%
2496
6%
768
29%
768
13%
1896
November1st to 15thNight
27%
765
13%
2492
10%
765
31%
765
13%
1838
November16th to endNight
23%
825
9%
2837
5%
825
29%
825
9%
2168
December1st to 15thNight
13%
825
6%
2925
1%
825
20%
825
7%
2377
December16th to endNight
18%
880
10%
3120
4%
880
26%
880
7%
2459

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
17%8%36%6%35%5%5%7%31%
49245
Night
17%9%36%5%35%45%6%32%
49009
TransparencyDay
50%8%14%18%7%
48924
Night
54%7%12%17%7%
48848
SeeingDay
22%16%25%22%10%2
6723
Night
21%20%25%24%8%
15253

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
14%13%5%7%7%35%5%5%6%23%
1472
16th to endDay
9%10%6%8%7%5%7%5%5%5%27%
1664
February1st to 15thDay
6%13%6%6%9%6%7%7%5%6%24%
1592
16th to endDay
14%12%410%6%45%5%5%5%26%
1577
March1st to 15thDay
15%9%5%7%6%26%5%45%29%
1820
16th to endDay
12%12%5%7%6%24446%33%
2157
April1st to 15thDay
21%8%36%5%24445%32%
2194
16th to endDay
20%9%25%5%33335%36%
2340
May1st to 15thDay
20%6%25%5%34446%34%
2403
16th to endDay
20%6%35%6%345%5%7%29%
2754
June1st to 15thDay
20%6%26%435%5%6%7%29%
2700
16th to endDay
19%6%35%7%45%47%7%28%
2700
July1st to 15thDay
15%5%25%5%36%5%7%11%31%
2679
16th to endDay
14%5%25%5%35%6%6%8%34%
2654
August1st to 15thDay
14%6%26%6%46%6%7%9%29%
2430
16th to endDay
12%424445%5%5%10%39%
2474
September1st to 15thDay
16%6%25%5%3445%6%39%
2085
16th to endDay
14%42442345%8%44%
1980
October1st to 15thDay
20%7%25%43435%5%37%
1872
16th to endDay
23%9%35%5%35%445%27%
1728
November1st to 15thDay
17%10%37%5%5%5%445%29%
1696
16th to endDay
19%12%6%7%6%24445%26%
1453
December1st to 15thDay
20%13%45%6%35%335%25%
1365
16th to endDay
19%13%49%7%3433426%
1456
January1st to 15thNight
14%12%49%8%36%5%5%6%23%
2794
16th to endNight
11%11%5%8%7%47%6%6%7%25%
2912
February1st to 15thNight
7%12%48%8%45%5%5%6%28%
2569
16th to endNight
15%13%5%10%6%34445%27%
1896
March1st to 15thNight
13%13%47%4345%46%32%
2117
16th to endNight
12%11%46%433446%37%
2064
April1st to 15thNight
20%11%47%5%3433431%
1754
16th to endNight
23%8%24323445%38%
1620
May1st to 15thNight
24%8%35%5%135%45%31%
1559
16th to endNight
23%6%36%5%35%44430%
1357
June1st to 15thNight
19%7%37%6%345%5%6%30%
1260
16th to endNight
20%6%36%6%346%5%8%30%
1260
July1st to 15thNight
17%6%36%5%345%5%8%34%
1278
16th to endNight
13%5%26%5%36%5%6%7%37%
1514
August1st to 15thNight
14%5%26%6%46%5%6%6%34%
1518
16th to endNight
13%3245%35%5%5%9%40%
1727
September1st to 15thNight
17%6%245%2445%6%39%
1875
16th to endNight
18%423323345%47%
1980
October1st to 15thNight
18%5%25%424446%40%
2085
16th to endNight
25%8%35%424446%32%
2496
November1st to 15thNight
19%9%36%32445%7%33%
2492
16th to endNight
17%10%47%5%35%45%6%29%
2837
December1st to 15thNight
19%14%5%7%5%25%44425%
2925
16th to endNight
18%11%5%8%7%35%45%5%24%
3120

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
62%8%11%14%4
1473
16th to endDay
58%6%12%15%7%
1664
February1st to 15thDay
58%7%14%12%6%1
1595
16th to endDay
61%47%16%7%
1577
March1st to 15thDay
55%6%10%13%12%1
1830
16th to endDay
52%5%10%20%10%1
2157
April1st to 15thDay
53%5%10%18%8%3
2194
16th to endDay
49%5%10%19%13%1
2340
May1st to 15thDay
48%7%13%19%10%
2403
16th to endDay
51%10%11%19%6%
2758
June1st to 15thDay
50%9%12%18%8%
2700
16th to endDay
50%9%15%16%7%
2700
July1st to 15thDay
43%9%20%20%6%
2521
16th to endDay
43%11%18%19%7%
2487
August1st to 15thDay
42%11%23%17%4
2416
16th to endDay
37%9%23%24%5%
2474
September1st to 15thDay
42%7%18%22%9%
2085
16th to endDay
37%7%17%27%9%
1980
October1st to 15thDay
47%7%16%19%8%
1872
16th to endDay
57%8%13%16%3
1728
November1st to 15thDay
53%9%14%18%4
1696
16th to endDay
61%8%11%14%4
1453
December1st to 15thDay
66%5%12%10%5%
1365
16th to endDay
65%5%9%12%5%
1456
January1st to 15thNight
64%7%10%12%4
2794
16th to endNight
59%6%10%16%6%
2912
February1st to 15thNight
56%8%12%17%5%
2570
16th to endNight
63%49%14%7%
1896
March1st to 15thNight
57%5%10%16%9%1
2130
16th to endNight
50%6%10%22%9%1
2064
April1st to 15thNight
59%46%14%12%1
1754
16th to endNight
49%6%8%19%14%1
1620
May1st to 15thNight
55%5%10%17%10%1
1559
16th to endNight
56%7%9%16%8%1
1359
June1st to 15thNight
53%6%12%17%8%1
1260
16th to endNight
51%8%14%16%8%
1260
July1st to 15thNight
45%10%16%21%6%
1207
16th to endNight
44%11%16%19%8%
1418
August1st to 15thNight
45%10%18%20%4
1508
16th to endNight
40%11%19%22%5%
1727
September1st to 15thNight
44%9%15%20%8%
1875
16th to endNight
40%7%15%25%10%
1980
October1st to 15thNight
46%6%13%23%8%
2085
16th to endNight
56%7%13%17%4
2496
November1st to 15thNight
53%9%14%15%7%
2492
16th to endNight
59%8%13%13%5%
2837
December1st to 15thNight
66%7%11%11%3
2925
16th to endNight
63%6%11%12%5%
3120

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%14%38%21%2
90
16th to endDay
14%17%42%16%8%
96
February1st to 15thDay
17%18%34%23%5%
173
16th to endDay
26%18%29%17%6%1
238
March1st to 15thDay
23%20%25%19%9%1
270
16th to endDay
19%19%25%20%12%2
288
April1st to 15thDay
26%23%23%18%5%1
270
16th to endDay
23%21%24%21%6%2
270
May1st to 15thDay
26%19%18%25%7%2
288
16th to endDay
22%20%27%19%8%1
468
June1st to 15thDay
23%18%24%21%10%1
495
16th to endDay
21%14%26%22%13%1
495
July1st to 15thDay
19%14%23%26%13%2
455
16th to endDay
15%14%20%32%15%1
326
August1st to 15thDay
16%9%23%26%18%5%
313
16th to endDay
18%11%25%21%15%6%
332
September1st to 15thDay
23%10%21%25%14%4
315
16th to endDay
16%12%26%25%13%5%
314
October1st to 15thDay
22%13%31%18%11%2
295
16th to endDay
33%15%25%17%6%1
288
November1st to 15thDay
25%17%27%21%7%1
280
16th to endDay
31%19%20%20%7%
178
December1st to 15thDay
30%8%36%17%5%1
90
16th to endDay
28%13%34%19%4
96
January1st to 15thNight
20%23%32%18%4
798
16th to endNight
15%21%26%28%7%
832
February1st to 15thNight
14%22%34%20%6%
760
16th to endNight
24%22%24%21%5%1
631
March1st to 15thNight
20%23%28%20%5%
720
16th to endNight
18%22%26%24%7%
768
April1st to 15thNight
24%23%25%19%5%
676
16th to endNight
24%22%23%22%6%
540
May1st to 15thNight
26%21%19%23%8%
479
16th to endNight
22%22%23%22%8%
375
June1st to 15thNight
21%18%23%28%7%1
360
16th to endNight
19%18%20%31%10%
360
July1st to 15thNight
19%14%22%30%12%1
340
16th to endNight
15%18%15%37%12%
376
August1st to 15thNight
16%11%12%34%22%1
437
16th to endNight
14%12%22%35%14%1
581
September1st to 15thNight
19%13%23%31%10%1
720
16th to endNight
19%11%24%30%11%1
717
October1st to 15thNight
21%15%27%25%8%1
720
16th to endNight
28%15%27%18%8%
768
November1st to 15thNight
24%21%23%21%7%1
765
16th to endNight
20%25%24%21%6%
825
December1st to 15thNight
27%22%28%16%4
825
16th to endNight
23%23%24%19%7%1
880
Page generated at 2018-02-15 10:58:43. Version ac04

Copyright 2018 A. Danko


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