Morin-Heights
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Morin-Heights clear sky chart from 2005-11-05 to

2017-09-12
.

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%
14590
13%
46789
7%
14558
34%
14558
16%
33029

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%
720
8%
2506
2%
716
21%
716
9%
1931
January16th to endNight
18%
768
11%
2688
5%
768
26%
768
11%
1994
February1st to 15thNight
16%
704
10%
2302
3%
701
26%
701
12%
1748
February16th to endNight
19%
631
13%
1910
5%
631
28%
631
12%
1415
March1st to 15thNight
17%
720
13%
2157
6%
720
26%
720
13%
1614
March16th to endNight
27%
768
20%
1995
7%
768
37%
768
23%
1370
April1st to 15thNight
23%
718
17%
1796
5%
718
29%
718
20%
1324
April16th to endNight
25%
633
16%
1713
5%
633
33%
633
20%
1205
May1st to 15thNight
24%
366
15%
1446
10%
366
35%
366
14%
979
May16th to endNight
28%
375
14%
1497
10%
374
41%
374
17%
976
June1st to 15thNight
28%
360
8%
1440
5%
360
36%
360
14%
1002
June16th to endNight
38%
360
8%
1440
10%
360
42%
360
17%
936
July1st to 15thNight
48%
340
12%
1360
16%
340
55%
340
24%
765
July16th to endNight
49%
376
12%
1418
15%
354
54%
354
23%
839
August1st to 15thNight
52%
368
13%
1439
13%
366
58%
366
21%
904
August16th to endNight
48%
747
20%
1893
9%
747
53%
747
35%
1194
September1st to 15thNight
41%
707
14%
1768
6%
707
45%
707
29%
1217
September16th to endNight
42%
657
20%
1793
12%
657
49%
657
31%
1144
October1st to 15thNight
29%
660
18%
1963
10%
660
40%
660
20%
1326
October16th to endNight
22%
704
11%
2247
5%
704
31%
704
14%
1646
November1st to 15thNight
24%
700
17%
2290
9%
700
35%
700
15%
1621
November16th to endNight
20%
720
12%
2520
7%
720
27%
720
11%
1835
December1st to 15thNight
15%
720
9%
2520
3%
720
22%
720
8%
1952
December16th to endNight
12%
768
10%
2688
3%
768
21%
768
7%
2092

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
18%9%46%6%34446%30%
47882
Night
16%9%46%5%34446%32%
46958
Cloud CoverDay
18%9%36%6%34446%31%
47891
Night
17%9%36%5%34446%33%
46964
TransparencyDay
53%5%11%18%9%1
47569
Night
51%5%12%19%9%1
46789
SeeingDay
23%13%30%21%8%2
5515
Night
22%13%31%23%8%
14590

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
20%15%5%8%8%2434420%
1432
16th to endDay
11%17%5%8%7%35%445%25%
1536
February1st to 15thDay
13%14%5%10%8%45%445%23%
1557
16th to endDay
14%17%5%8%6%245%4425%
1563
March1st to 15thDay
16%12%5%10%7%3434426%
1790
16th to endDay
15%10%36%5%24346%36%
2229
April1st to 15thDay
22%9%45%5%23345%32%
2152
16th to endDay
20%9%35%5%34445%34%
2251
May1st to 15thDay
21%8%37%6%35%436%28%
2511
16th to endDay
22%7%45%5%35%446%30%
2618
June1st to 15thDay
22%7%36%6%35%5%6%7%26%
2520
16th to endDay
21%7%37%6%35%5%6%6%26%
2520
July1st to 15thDay
15%5%35%5%46%45%7%34%
2520
16th to endDay
13%6%37%6%45%6%7%8%30%
2654
August1st to 15thDay
15%6%36%6%46%6%6%7%30%
2510
16th to endDay
11%5%25%5%36%45%9%40%
2297
September1st to 15thDay
19%6%25%5%34446%36%
2112
16th to endDay
18%5%24323345%45%
1836
October1st to 15thDay
23%8%35%5%23445%32%
1667
16th to endDay
25%12%46%6%44446%22%
1625
November1st to 15thDay
16%9%46%5%345%6%6%30%
1566
16th to endDay
24%11%45%5%24345%27%
1440
December1st to 15thDay
22%17%5%8%5%24436%20%
1440
16th to endDay
21%15%7%9%6%2343320%
1536
January1st to 15thNight
15%16%6%9%7%35%446%19%
2506
16th to endNight
9%14%6%9%6%45%445%26%
2688
February1st to 15thNight
10%14%5%10%7%45%445%24%
2300
16th to endNight
15%12%5%8%7%25%45%5%27%
1910
March1st to 15thNight
17%10%5%8%6%36%445%27%
2144
16th to endNight
13%9%36%5%33345%41%
1995
April1st to 15thNight
23%9%3443434434%
1796
16th to endNight
20%7%26%424446%37%
1713
May1st to 15thNight
19%8%36%6%23435%35%
1446
16th to endNight
20%6%25%5%24347%36%
1495
June1st to 15thNight
22%8%35%5%335%47%29%
1440
16th to endNight
18%6%236%35%5%5%8%35%
1440
July1st to 15thNight
11%5%245%2446%9%43%
1440
16th to endNight
11%4345%25%5%6%7%43%
1514
August1st to 15thNight
10%5%25%6%35%46%9%38%
1449
16th to endNight
11%41443435%7%49%
1893
September1st to 15thNight
14%5%25%4345%5%6%41%
1768
16th to endNight
17%414323346%47%
1793
October1st to 15thNight
17%7%37%5%3345%5%36%
1963
16th to endNight
25%8%35%5%3435%6%28%
2247
November1st to 15thNight
18%8%47%6%2445%6%32%
2290
16th to endNight
20%13%47%5%24445%27%
2520
December1st to 15thNight
19%14%6%7%6%3435%6%21%
2520
16th to endNight
21%15%6%7%6%34345%21%
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
19%14%6%8%7%3444422%
1432
16th to endDay
11%15%6%8%6%35%45%427%
1536
February1st to 15thDay
12%15%5%9%8%45%45%424%
1557
16th to endDay
15%16%5%8%6%3444426%
1563
March1st to 15thDay
17%12%5%10%7%3433427%
1800
16th to endDay
16%10%35%5%23446%37%
2228
April1st to 15thDay
22%10%35%5%23335%33%
2152
16th to endDay
20%8%35%5%34345%34%
2251
May1st to 15thDay
22%8%36%6%34446%29%
2511
16th to endDay
22%7%25%6%35%446%31%
2618
June1st to 15thDay
22%6%36%6%35%5%5%7%27%
2520
16th to endDay
21%7%26%6%45%5%6%7%26%
2520
July1st to 15thDay
14%6%35%5%36%5%5%8%35%
2520
16th to endDay
13%6%36%6%36%6%6%8%31%
2654
August1st to 15thDay
14%7%26%7%36%6%6%7%31%
2510
16th to endDay
10%6%25%5%345%5%8%42%
2297
September1st to 15thDay
19%6%26%43445%7%36%
2112
16th to endDay
17%6%34422335%45%
1836
October1st to 15thDay
23%8%345%23435%33%
1667
16th to endDay
25%11%37%6%44435%24%
1625
November1st to 15thDay
16%8%46%6%3446%7%31%
1566
16th to endDay
24%10%46%4245%45%28%
1440
December1st to 15thDay
22%15%5%8%5%24426%21%
1440
16th to endDay
22%15%6%8%6%2443421%
1536
January1st to 15thNight
15%15%6%9%6%44446%21%
2506
16th to endNight
10%13%6%8%7%45%445%28%
2688
February1st to 15thNight
10%13%5%10%8%46%45%425%
2293
16th to endNight
15%12%48%7%3445%429%
1910
March1st to 15thNight
17%11%47%6%35%445%28%
2157
16th to endNight
14%8%36%5%23435%42%
1995
April1st to 15thNight
24%8%3443344435%
1796
16th to endNight
20%7%25%424445%37%
1713
May1st to 15thNight
19%9%26%5%3443435%
1446
16th to endNight
21%5%25%434347%37%
1495
June1st to 15thNight
23%8%25%5%23446%31%
1440
16th to endNight
18%6%335%245%5%7%36%
1440
July1st to 15thNight
10%425%4245%5%8%44%
1440
16th to endNight
11%425%425%5%6%7%43%
1514
August1st to 15thNight
11%425%5%35%6%6%8%39%
1449
16th to endNight
11%41432435%7%50%
1893
September1st to 15thNight
14%6%245%25%447%42%
1768
16th to endNight
17%324323346%47%
1793
October1st to 15thNight
18%6%26%434446%37%
1963
16th to endNight
24%9%35%5%24346%30%
2247
November1st to 15thNight
17%8%36%6%345%46%33%
2290
16th to endNight
20%12%47%5%24345%29%
2520
December1st to 15thNight
19%14%5%7%5%34446%24%
2520
16th to endNight
21%14%6%7%5%3443423%
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
64%5%9%14%5%
1433
16th to endDay
59%310%16%8%1
1536
February1st to 15thDay
61%5%8%18%5%
1559
16th to endDay
60%39%15%8%1
1563
March1st to 15thDay
61%39%14%9%1
1800
16th to endDay
47%39%18%15%4
2229
April1st to 15thDay
54%37%19%12%3
2152
16th to endDay
51%47%19%12%4
2251
May1st to 15thDay
55%38%17%12%2
2511
16th to endDay
52%5%10%18%11%1
2622
June1st to 15thDay
54%6%12%15%9%1
2520
16th to endDay
54%6%11%17%8%1
2520
July1st to 15thDay
43%7%15%24%9%
2371
16th to endDay
47%7%16%19%8%
2487
August1st to 15thDay
49%8%15%20%6%
2496
16th to endDay
39%7%17%25%10%
2297
September1st to 15thDay
46%5%12%23%11%
2112
16th to endDay
39%414%30%10%
1836
October1st to 15thDay
51%5%10%21%10%
1667
16th to endDay
62%313%13%5%
1625
November1st to 15thDay
49%7%16%16%9%
1566
16th to endDay
57%414%16%6%
1440
December1st to 15thDay
66%412%12%3
1440
16th to endDay
65%410%10%7%
1536
January1st to 15thNight
62%5%13%13%5%
2506
16th to endNight
57%6%10%15%8%1
2688
February1st to 15thNight
59%5%10%18%5%
2302
16th to endNight
56%5%11%15%9%1
1910
March1st to 15thNight
57%5%9%16%9%1
2157
16th to endNight
45%311%18%17%3
1995
April1st to 15thNight
52%37%20%14%1
1796
16th to endNight
47%5%9%18%15%2
1713
May1st to 15thNight
52%48%16%14%4
1446
16th to endNight
47%5%9%21%14%1
1497
June1st to 15thNight
53%5%11%19%9%
1440
16th to endNight
45%7%11%21%12%1
1440
July1st to 15thNight
34%7%17%26%13%
1360
16th to endNight
37%7%17%24%12%
1418
August1st to 15thNight
39%10%17%23%9%
1439
16th to endNight
32%7%17%31%11%
1893
September1st to 15thNight
41%6%14%24%12%
1768
16th to endNight
37%412%32%11%
1793
October1st to 15thNight
46%413%23%11%
1963
16th to endNight
54%5%14%17%7%
2247
November1st to 15thNight
51%6%13%18%7%2
2290
16th to endNight
56%5%13%17%6%
2520
December1st to 15thNight
61%6%12%14%3
2520
16th to endNight
64%5%11%12%6%
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
25%16%36%16%5%
60
16th to endDay
28%20%39%7%31
64
February1st to 15thDay
36%25%33%31
87
16th to endDay
26%20%29%19%4
222
March1st to 15thDay
27%20%27%20%3
270
16th to endDay
23%17%31%16%8%2
288
April1st to 15thDay
32%16%29%14%6%1
270
16th to endDay
25%17%29%18%7%1
270
May1st to 15thDay
32%13%28%17%6%1
288
16th to endDay
26%16%31%18%6%
331
June1st to 15thDay
27%14%33%17%6%
315
16th to endDay
25%9%35%22%6%1
315
July1st to 15thDay
14%10%38%22%9%3
305
16th to endDay
15%431%36%10%2
326
August1st to 15thDay
15%7%29%29%15%2
313
16th to endDay
14%7%28%26%12%9%
332
September1st to 15thDay
21%8%25%26%12%6%
299
16th to endDay
19%12%25%21%13%7%
254
October1st to 15thDay
24%16%25%20%11%1
255
16th to endDay
31%12%27%20%6%
247
November1st to 15thDay
20%20%29%21%6%1
220
16th to endDay
36%15%31%16%
60
December1st to 15thDay
26%20%36%15%1
60
16th to endDay
37%37%21%3
64
January1st to 15thNight
24%18%35%18%4
720
16th to endNight
17%17%36%21%6%1
768
February1st to 15thNight
18%16%39%18%5%
704
16th to endNight
23%16%34%21%3
631
March1st to 15thNight
25%16%36%19%2
720
16th to endNight
19%15%31%24%7%1
768
April1st to 15thNight
28%14%29%23%4
718
16th to endNight
25%14%31%19%7%
633
May1st to 15thNight
24%10%34%21%7%1
366
16th to endNight
23%8%35%25%7%
375
June1st to 15thNight
29%8%27%27%6%
360
16th to endNight
21%428%31%13%
360
July1st to 15thNight
10%8%29%34%15%1
340
16th to endNight
13%327%41%13%1
376
August1st to 15thNight
13%223%37%20%1
368
16th to endNight
12%6%26%31%20%2
747
September1st to 15thNight
16%6%30%31%13%1
707
16th to endNight
19%9%25%25%17%2
657
October1st to 15thNight
23%11%30%25%9%
660
16th to endNight
31%12%27%21%6%
704
November1st to 15thNight
23%14%31%21%8%1
700
16th to endNight
26%18%26%18%7%1
720
December1st to 15thNight
29%18%29%17%4
720
16th to endNight
31%17%30%15%31
768
Page generated at 2017-09-13 07:39:03. Version ac04

Copyright 2017 A. Danko


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