Mont-Laurier
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mont-Laurier 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
29%
14542
12%
46797
8%
14512
34%
14512
15%
34208

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
16%
720
6%
2506
4%
716
20%
716
7%
2082
January16th to endNight
22%
768
9%
2679
6%
768
28%
768
10%
2071
February1st to 15thNight
19%
703
10%
2287
5%
701
26%
701
10%
1800
February16th to endNight
21%
631
11%
1953
6%
631
28%
631
11%
1520
March1st to 15thNight
23%
720
13%
2115
7%
720
29%
720
13%
1647
March16th to endNight
30%
768
19%
2024
9%
768
38%
768
22%
1429
April1st to 15thNight
27%
718
16%
1796
7%
718
31%
718
20%
1343
April16th to endNight
31%
605
17%
1685
9%
605
37%
605
22%
1170
May1st to 15thNight
30%
360
16%
1440
16%
360
38%
360
16%
955
May16th to endNight
31%
374
12%
1497
11%
374
42%
374
16%
997
June1st to 15thNight
31%
360
7%
1440
6%
360
38%
360
15%
978
June16th to endNight
45%
360
7%
1440
10%
360
47%
360
20%
902
July1st to 15thNight
49%
340
10%
1360
14%
340
54%
340
23%
781
July16th to endNight
54%
376
12%
1418
17%
354
55%
354
24%
832
August1st to 15thNight
50%
401
14%
1472
14%
399
54%
399
22%
939
August16th to endNight
51%
702
19%
1848
9%
702
56%
702
35%
1151
September1st to 15thNight
40%
707
13%
1768
5%
707
42%
707
27%
1235
September16th to endNight
41%
657
18%
1792
12%
657
45%
657
29%
1188
October1st to 15thNight
27%
660
17%
1980
10%
660
36%
660
18%
1415
October16th to endNight
23%
704
9%
2222
6%
704
28%
704
12%
1731
November1st to 15thNight
25%
700
15%
2347
11%
700
32%
700
13%
1734
November16th to endNight
18%
720
10%
2520
7%
720
24%
720
8%
2011
December1st to 15thNight
15%
720
6%
2520
3%
720
20%
720
7%
2082
December16th to endNight
14%
768
10%
2688
5%
768
20%
768
7%
2215

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%10%47%6%34446%28%
47871
Night
19%11%47%6%34445%28%
46966
TransparencyDay
57%310%19%8%
47558
Night
57%310%19%8%
46797
SeeingDay
27%9%28%20%10%3
5423
Night
26%9%26%25%10%1
14544

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
22%18%7%11%6%2422416%
1432
16th to endDay
14%15%7%10%6%25%45%6%20%
1545
February1st to 15thDay
9%17%7%12%10%5%4345%18%
1575
16th to endDay
16%18%7%9%6%3323424%
1519
March1st to 15thDay
15%14%6%9%6%3444425%
1832
16th to endDay
15%9%46%5%34446%35%
2199
April1st to 15thDay
23%13%45%5%33335%29%
2152
16th to endDay
21%9%35%434345%34%
2283
May1st to 15thDay
24%9%35%5%24446%29%
2511
16th to endDay
21%8%35%5%34446%31%
2618
June1st to 15thDay
23%7%36%7%36%45%6%26%
2520
16th to endDay
18%5%26%6%36%5%6%7%29%
2520
July1st to 15thDay
18%6%24435%5%5%8%33%
2520
16th to endDay
14%6%37%6%35%5%6%8%32%
2654
August1st to 15thDay
16%7%36%6%36%5%6%7%28%
2476
16th to endDay
14%6%26%6%35%5%6%7%36%
2341
September1st to 15thDay
21%7%26%423346%35%
2112
16th to endDay
21%5%24423446%40%
1837
October1st to 15thDay
25%9%26%5%33436%28%
1650
16th to endDay
30%13%48%5%3443418%
1650
November1st to 15thDay
19%11%47%5%2345%6%28%
1509
16th to endDay
26%16%6%8%5%1322421%
1440
December1st to 15thDay
23%20%7%9%7%3243413%
1440
16th to endDay
22%17%7%9%7%3433416%
1536
January1st to 15thNight
21%17%6%10%7%3444414%
2506
16th to endNight
14%16%7%8%7%45%5%46%20%
2679
February1st to 15thNight
11%14%7%11%10%45%44421%
2285
16th to endNight
15%13%6%10%7%36%34422%
1953
March1st to 15thNight
19%13%5%7%6%36%44423%
2102
16th to endNight
14%8%5%6%6%3334438%
2024
April1st to 15thNight
24%9%445%3424432%
1796
16th to endNight
21%7%25%424345%38%
1685
May1st to 15thNight
21%10%36%32435%5%33%
1440
16th to endNight
18%8%25%5%3445%6%33%
1495
June1st to 15thNight
19%8%35%6%3447%7%29%
1440
16th to endNight
16%5%346%3445%8%36%
1440
July1st to 15thNight
12%4245%346%5%7%41%
1440
16th to endNight
10%435%5%246%6%8%41%
1514
August1st to 15thNight
12%6%35%5%45%5%6%8%36%
1482
16th to endNight
13%42432346%8%45%
1848
September1st to 15thNight
19%7%25%5%24445%38%
1768
16th to endNight
19%5%15%423435%44%
1792
October1st to 15thNight
24%8%36%5%33345%33%
1980
16th to endNight
29%12%36%5%24445%21%
2222
November1st to 15thNight
21%11%47%5%3434428%
2347
16th to endNight
25%15%6%8%5%2344419%
2520
December1st to 15thNight
22%18%8%8%6%3442415%
2520
16th to endNight
22%18%6%9%6%3434415%
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
74%16%12%5%
1433
16th to endDay
64%38%15%7%
1545
February1st to 15thDay
68%18%14%6%
1577
16th to endDay
65%16%16%9%
1519
March1st to 15thDay
61%29%16%9%1
1842
16th to endDay
50%38%20%14%3
2199
April1st to 15thDay
58%27%18%10%2
2152
16th to endDay
53%27%20%12%3
2283
May1st to 15thDay
56%26%20%12%1
2511
16th to endDay
54%310%19%11%1
2622
June1st to 15thDay
58%39%20%9%
2520
16th to endDay
50%413%21%9%
2520
July1st to 15thDay
45%414%24%10%
2371
16th to endDay
50%316%20%8%
2487
August1st to 15thDay
52%5%14%21%5%
2462
16th to endDay
44%416%25%8%
2341
September1st to 15thDay
49%213%21%11%
2112
16th to endDay
45%313%29%8%
1837
October1st to 15thDay
57%211%19%8%
1650
16th to endDay
70%39%12%4
1650
November1st to 15thDay
56%314%17%7%
1509
16th to endDay
69%29%12%5%
1440
December1st to 15thDay
74%28%12%1
1440
16th to endDay
73%26%11%5%
1536
January1st to 15thNight
74%28%11%3
2506
16th to endNight
65%28%15%6%
2679
February1st to 15thNight
66%28%16%5%
2287
16th to endNight
65%28%15%8%
1953
March1st to 15thNight
62%36%17%8%
2115
16th to endNight
49%28%20%15%2
2024
April1st to 15thNight
56%15%20%13%2
1796
16th to endNight
49%28%21%15%2
1685
May1st to 15thNight
52%26%20%14%3
1440
16th to endNight
51%310%21%11%1
1497
June1st to 15thNight
52%312%20%9%
1440
16th to endNight
45%414%22%12%
1440
July1st to 15thNight
39%317%24%13%
1360
16th to endNight
39%5%17%28%9%
1418
August1st to 15thNight
43%5%17%25%7%
1472
16th to endNight
35%319%32%7%
1848
September1st to 15thNight
47%214%24%10%
1768
16th to endNight
43%213%32%7%
1792
October1st to 15thNight
54%211%21%10%
1980
16th to endNight
63%310%16%4
2222
November1st to 15thNight
59%311%17%8%
2347
16th to endNight
68%39%14%4
2520
December1st to 15thNight
72%39%12%2
2520
16th to endNight
72%27%11%5%
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
28%20%30%15%6%
60
16th to endDay
40%7%30%15%6%
65
February1st to 15thDay
22%18%45%10%3
90
16th to endDay
34%15%27%17%5%
178
March1st to 15thDay
27%15%32%17%7%
270
16th to endDay
23%15%29%19%8%3
288
April1st to 15thDay
31%13%24%21%8%
270
16th to endDay
28%12%28%16%12%1
270
May1st to 15thDay
35%8%26%18%7%3
288
16th to endDay
29%11%30%16%10%2
331
June1st to 15thDay
33%7%30%19%7%1
315
16th to endDay
18%7%33%26%10%2
315
July1st to 15thDay
19%5%34%26%10%3
305
16th to endDay
19%5%23%32%15%3
326
August1st to 15thDay
24%323%27%16%6%
313
16th to endDay
18%6%29%22%14%8%
332
September1st to 15thDay
27%7%21%20%12%10%
299
16th to endDay
25%9%23%20%12%8%
254
October1st to 15thDay
32%12%23%18%9%3
255
16th to endDay
41%7%24%16%8%
252
November1st to 15thDay
25%11%31%22%9%
163
16th to endDay
38%15%26%13%5%1
60
December1st to 15thDay
36%16%30%13%3
60
16th to endDay
39%25%29%6%
64
January1st to 15thNight
32%10%29%22%4
720
16th to endNight
22%11%30%25%8%1
768
February1st to 15thNight
18%12%35%23%8%1
704
16th to endNight
23%13%33%23%6%
631
March1st to 15thNight
29%13%26%25%4
720
16th to endNight
20%14%28%25%9%1
768
April1st to 15thNight
31%11%23%26%6%
718
16th to endNight
28%11%25%24%10%
605
May1st to 15thNight
27%5%29%26%10%
360
16th to endNight
23%8%29%27%10%
375
June1st to 15thNight
26%6%27%29%9%
360
16th to endNight
18%5%22%38%14%
360
July1st to 15thNight
14%326%36%19%
340
16th to endNight
11%421%43%16%2
376
August1st to 15thNight
19%218%31%24%3
401
16th to endNight
16%5%21%32%22%2
702
September1st to 15thNight
24%423%29%16%1
707
16th to endNight
23%5%25%26%16%1
657
October1st to 15thNight
30%9%26%23%9%1
660
16th to endNight
39%8%23%22%6%
704
November1st to 15thNight
29%12%25%22%9%1
700
16th to endNight
35%14%24%18%6%1
720
December1st to 15thNight
33%14%27%20%4
720
16th to endNight
34%11%28%18%5%1
768
Page generated at 2017-09-13 07:39:03. Version ac04

Copyright 2017 A. Danko


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