Marten River Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Marten River Provincial Park clear sky chart from 2005-11-06 to 2024-01-13.

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
26%
23171
13%
74776
7%
23128
32%
23128
15%
54753

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 10thNight
13%
949
7%
2838
4%
946
17%
946
8%
2369
January11th to 20thNight
17%
899
8%
2697
3%
899
21%
899
8%
2208
January21st to endNight
23%
792
13%
2574
8%
792
29%
792
11%
1997
February1st to 10thNight
16%
720
9%
2340
4%
720
22%
720
9%
1817
February11th to 20thNight
15%
701
12%
2275
4%
700
25%
700
11%
1761
February21st to endNight
15%
592
12%
1911
4%
592
24%
592
10%
1466
March1st to 10thNight
19%
720
15%
2008
7%
720
27%
720
15%
1496
March11th to 20thNight
20%
720
15%
1980
6%
720
27%
720
16%
1468
March21st to endNight
24%
792
19%
2178
7%
792
33%
792
20%
1520
April1st to 10thNight
22%
720
13%
1828
5%
720
27%
720
17%
1401
April11th to 20thNight
25%
579
18%
1643
8%
579
31%
579
18%
1174
April21st to endNight
27%
540
15%
1620
7%
540
34%
540
18%
1157
May1st to 10thNight
32%
464
15%
1544
11%
464
39%
464
20%
1025
May11th to 20thNight
29%
354
19%
1415
16%
354
44%
354
18%
889
May21st to endNight
33%
388
12%
1549
11%
388
43%
388
22%
911
June1st to 10thNight
37%
360
12%
1260
10%
360
44%
360
21%
821
June11th to 20thNight
37%
360
14%
1260
10%
360
46%
360
24%
763
June21st to endNight
38%
360
10%
1260
8%
360
43%
360
20%
821
July1st to 10thNight
44%
350
15%
1225
15%
350
50%
350
29%
692
July11th to 20thNight
47%
348
17%
1218
14%
348
56%
348
28%
710
July21st to endNight
49%
434
15%
1498
15%
410
53%
410
27%
863
August1st to 10thNight
44%
537
14%
1600
10%
534
48%
534
26%
1038
August11th to 20thNight
48%
534
17%
1598
11%
534
53%
534
29%
999
August21st to endNight
40%
616
18%
1804
10%
616
44%
616
25%
1187
September1st to 10thNight
43%
720
18%
1800
9%
720
47%
720
33%
1179
September11th to 20thNight
41%
720
20%
1903
12%
720
44%
720
31%
1235
September21st to endNight
39%
720
19%
2012
12%
720
44%
720
26%
1345
October1st to 10thNight
33%
720
16%
2160
12%
720
39%
720
19%
1508
October11th to 20thNight
22%
720
13%
2160
7%
720
30%
720
14%
1657
October21st to endNight
18%
792
11%
2426
5%
792
26%
792
11%
1921
November1st to 10thNight
23%
740
13%
2582
8%
740
32%
740
15%
1834
November11th to 20thNight
18%
760
12%
2660
7%
760
26%
760
10%
2052
November21st to endNight
16%
760
7%
2660
4%
760
21%
760
8%
2156
December1st to 10thNight
13%
760
8%
2660
3%
760
20%
760
6%
2192
December11th to 20thNight
15%
893
9%
3446
4%
892
23%
892
8%
2733
December21st to endNight
13%
1037
6%
5184
2%
1026
18%
1026
4%
4388

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%11%48%6%3445%6%29%
74708
Night
17%13%5%8%6%34446%29%
75013
TransparencyDay
56%310%20%9%1
74405
Night
58%310%19%9%1
74851
SeeingDay
25%13%31%21%8%2
13987
Night
25%11%30%24%9%1
23183

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 10thDay
16%21%8%12%7%44445%14%
1328
11th to 20thDay
16%19%7%10%7%34435%21%
1301
21st to endDay
15%14%7%12%9%5%5%45%5%19%
1782
February1st to 10thDay
9%19%7%11%11%5%6%5%4419%
1620
11th to 20thDay
13%17%7%9%8%34445%24%
1573
21st to endDay
16%16%6%11%7%5%5%5%45%20%
1340
March1st to 10thDay
14%13%6%9%6%35%45%5%29%
1948
11th to 20thDay
13%14%5%9%9%45%44429%
1980
21st to endDay
17%11%49%5%24345%35%
2178
April1st to 10thDay
21%13%48%6%34447%26%
2132
11th to 20thDay
22%9%46%6%34445%33%
2282
21st to endDay
22%12%37%434345%34%
2340
May1st to 10thDay
19%9%37%6%3445%7%33%
2416
11th to 20thDay
21%8%46%5%3446%7%32%
2478
21st to endDay
18%6%36%5%35%348%39%
2725
June1st to 10thDay
18%9%46%5%35%5%5%6%33%
2699
11th to 20thDay
16%6%35%6%35%7%6%7%36%
2700
21st to endDay
18%7%46%6%46%5%6%7%31%
2700
July1st to 10thDay
13%5%36%6%35%5%6%8%40%
2700
11th to 20thDay
14%6%36%5%45%5%7%9%36%
2700
21st to endDay
13%6%26%7%45%6%6%9%35%
2727
August1st to 10thDay
15%8%36%5%45%6%6%9%33%
2327
11th to 20thDay
17%6%35%6%35%6%5%8%37%
2303
21st to endDay
16%8%36%6%445%6%8%33%
2534
September1st to 10thDay
18%7%36%5%25%5%5%7%37%
2160
11th to 20thDay
19%6%35%6%35%5%6%8%35%
2053
21st to endDay
23%8%36%5%3435%6%32%
1947
October1st to 10thDay
20%11%46%5%35%45%6%32%
1800
11th to 20thDay
26%14%47%6%35%445%22%
1800
21st to endDay
29%17%47%6%34346%19%
1926
November1st to 10thDay
20%14%48%6%34446%27%
1494
11th to 20thDay
19%16%6%10%7%45%5%36%19%
1520
21st to endDay
26%19%5%10%7%3434414%
1520
December1st to 10thDay
18%19%7%11%8%445%45%15%
1520
11th to 20thDay
18%18%7%11%7%2344422%
1724
21st to endDay
18%21%10%15%8%3322315%
2431
January1st to 10thNight
16%20%8%11%8%4444417%
2838
11th to 20thNight
18%18%8%10%7%45%44419%
2697
21st to endNight
14%13%5%11%9%5%6%5%5%6%22%
2574
February1st to 10thNight
11%15%6%11%10%5%7%446%21%
2340
11th to 20thNight
13%16%8%11%7%45%445%23%
2273
21st to endNight
14%18%5%9%8%4445%5%23%
1911
March1st to 10thNight
13%13%6%9%7%45%446%30%
1998
11th to 20thNight
16%11%6%8%7%3445%6%29%
1979
21st to endNight
15%11%47%5%24446%37%
2178
April1st to 10thNight
21%13%6%7%5%3445%429%
1828
11th to 20thNight
20%9%47%6%245%46%34%
1643
21st to endNight
21%10%36%6%35%5%5%6%32%
1620
May1st to 10thNight
17%9%37%5%345%5%6%36%
1544
11th to 20thNight
18%6%36%5%36%45%7%36%
1415
21st to endNight
14%8%25%4345%6%6%43%
1548
June1st to 10thNight
16%8%47%5%4445%6%38%
1260
11th to 20thNight
16%7%35%334348%43%
1260
21st to endNight
15%7%36%6%36%5%5%8%37%
1260
July1st to 10thNight
10%4346%346%7%10%44%
1260
11th to 20thNight
12%6%35%5%34448%46%
1260
21st to endNight
10%5%36%5%345%6%10%44%
1586
August1st to 10thNight
14%5%26%6%45%6%6%6%41%
1611
11th to 20thNight
12%6%35%6%35%46%7%44%
1598
21st to endNight
17%8%27%5%3435%7%40%
1804
September1st to 10thNight
16%6%2443445%7%46%
1800
11th to 20thNight
17%7%25%324446%46%
1903
21st to endNight
18%8%25%5%2445%7%40%
2012
October1st to 10thNight
20%10%36%5%3445%6%35%
2160
11th to 20thNight
28%12%36%5%34435%26%
2160
21st to endNight
26%15%5%8%5%3433423%
2426
November1st to 10thNight
20%11%37%5%45%5%5%6%30%
2582
11th to 20thNight
19%15%5%9%8%44446%22%
2660
21st to endNight
23%18%5%9%8%35%45%417%
2660
December1st to 10thNight
20%20%7%10%8%44345%16%
2660
11th to 20thNight
18%19%6%9%6%45%46%6%17%
3469
21st to endNight
20%21%9%12%9%3333314%
5236

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 10thDay
73%38%13%3
1329
11th to 20thDay
68%27%13%9%1
1301
21st to endDay
68%35%16%8%1
1782
February1st to 10thDay
69%37%13%7%1
1620
11th to 20thDay
64%38%14%10%1
1582
21st to endDay
67%25%16%10%
1340
March1st to 10thDay
59%210%17%11%1
1951
11th to 20thDay
60%37%19%9%1
1980
21st to endDay
54%18%18%16%3
2178
April1st to 10thDay
59%39%18%10%1
2132
11th to 20thDay
55%26%24%11%1
2282
21st to endDay
55%27%18%15%3
2340
May1st to 10thDay
52%29%21%14%2
2416
11th to 20thDay
52%38%22%13%1
2482
21st to endDay
46%313%23%13%2
2725
June1st to 10thDay
52%310%24%11%1
2699
11th to 20thDay
46%411%25%13%1
2700
21st to endDay
51%412%21%10%1
2700
July1st to 10thDay
41%313%31%10%1
2626
11th to 20thDay
43%314%30%9%
2619
21st to endDay
47%414%28%7%
2575
August1st to 10thDay
47%416%24%9%
2314
11th to 20thDay
46%417%25%7%1
2303
21st to endDay
49%314%26%8%
2534
September1st to 10thDay
48%313%24%10%1
2160
11th to 20thDay
47%414%27%7%
2053
21st to endDay
54%413%24%5%
1947
October1st to 10thDay
55%312%21%9%1
1800
11th to 20thDay
67%310%15%5%
1800
21st to endDay
69%310%12%6%
1926
November1st to 10thDay
61%313%17%6%
1494
11th to 20thDay
68%211%13%5%1
1520
21st to endDay
76%28%9%4
1520
December1st to 10thDay
73%38%11%4
1520
11th to 20thDay
67%29%17%5%
1724
21st to endDay
78%16%12%2
2431
January1st to 10thNight
73%38%13%4
2838
11th to 20thNight
71%27%12%7%1
2697
21st to endNight
65%35%15%11%1
2574
February1st to 10thNight
65%38%15%7%1
2340
11th to 20thNight
65%39%16%7%1
2275
21st to endNight
64%37%16%9%1
1911
March1st to 10thNight
59%29%16%12%3
2008
11th to 20thNight
58%211%18%11%1
1980
21st to endNight
50%38%19%15%4
2178
April1st to 10thNight
59%28%17%13%2
1828
11th to 20thNight
54%25%22%15%2
1643
21st to endNight
53%310%15%16%3
1620
May1st to 10thNight
50%29%22%15%2
1544
11th to 20thNight
48%36%25%15%3
1416
21st to endNight
41%315%21%17%2
1549
June1st to 10thNight
48%310%25%11%3
1260
11th to 20thNight
41%312%26%16%2
1260
21st to endNight
47%5%13%21%14%1
1260
July1st to 10thNight
35%5%13%31%14%2
1225
11th to 20thNight
38%314%31%12%1
1218
21st to endNight
38%319%30%9%
1498
August1st to 10thNight
42%5%16%25%10%1
1600
11th to 20thNight
40%417%29%9%1
1598
21st to endNight
45%315%26%10%1
1804
September1st to 10thNight
38%416%29%11%2
1800
11th to 20thNight
41%315%32%9%
1903
21st to endNight
46%216%29%7%
2012
October1st to 10thNight
52%312%21%12%
2160
11th to 20thNight
62%211%20%5%
2160
21st to endNight
66%210%14%7%
2426
November1st to 10thNight
56%315%20%6%
2582
11th to 20thNight
66%310%15%6%1
2660
21st to endNight
71%311%11%4
2660
December1st to 10thNight
74%28%13%3
2660
11th to 20thNight
69%28%15%6%
3468
21st to endNight
78%15%12%4
5236

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 10thDay
28%16%34%17%41
180
11th to 20thDay
24%12%39%16%9%
172
21st to endDay
26%8%38%19%7%2
264
February1st to 10thDay
32%25%29%9%4
240
11th to 20thDay
27%21%37%14%1
240
21st to endDay
34%23%34%8%1
198
March1st to 10thDay
23%19%35%19%4
391
11th to 20thDay
22%18%36%19%41
420
21st to endDay
29%18%32%16%41
462
April1st to 10thDay
27%18%28%19%7%1
420
11th to 20thDay
35%15%24%17%7%2
412
21st to endDay
32%16%32%12%5%2
420
May1st to 10thDay
26%12%29%20%12%1
423
11th to 20thDay
24%14%29%21%9%2
447
21st to endDay
22%13%33%21%8%2
485
June1st to 10thDay
21%14%35%21%6%2
629
11th to 20thDay
17%16%32%25%9%2
630
21st to endDay
21%10%32%25%10%2
630
July1st to 10thDay
13%10%33%32%10%2
621
11th to 20thDay
17%9%30%27%14%3
618
21st to endDay
15%7%32%30%12%4
513
August1st to 10thDay
22%6%25%29%14%4
446
11th to 20thDay
18%426%27%16%9%
439
21st to endDay
22%9%27%23%14%5%
495
September1st to 10thDay
24%11%28%23%10%4
450
11th to 20thDay
20%6%32%29%8%4
450
21st to endDay
30%8%25%22%11%3
450
October1st to 10thDay
29%12%26%19%11%2
450
11th to 20thDay
32%17%34%12%42
450
21st to endDay
34%15%35%13%2
441
November1st to 10thDay
38%13%35%13%11
183
11th to 20thDay
27%21%33%15%32
180
21st to endDay
41%15%27%15%21
180
December1st to 10thDay
32%13%34%19%2
180
11th to 20thDay
31%17%36%12%41
180
21st to endDay
33%16%34%13%41
198
January1st to 10thNight
27%13%33%21%6%
950
11th to 20thNight
31%13%29%22%6%
899
21st to endNight
22%11%32%24%10%1
792
February1st to 10thNight
19%17%38%21%41
720
11th to 20thNight
23%15%37%19%5%
703
21st to endNight
24%18%33%21%4
592
March1st to 10thNight
21%18%34%21%5%
720
11th to 20thNight
24%16%35%18%7%1
720
21st to endNight
21%15%33%25%6%1
792
April1st to 10thNight
29%13%30%23%5%
720
11th to 20thNight
26%15%28%22%8%1
579
21st to endNight
28%10%28%24%8%1
540
May1st to 10thNight
21%8%30%31%9%1
464
11th to 20thNight
23%8%32%25%11%1
354
21st to endNight
18%9%35%31%6%
389
June1st to 10thNight
20%6%30%34%10%
360
11th to 20thNight
21%8%28%31%12%1
360
21st to endNight
21%7%25%30%16%1
360
July1st to 10thNight
12%433%40%11%1
350
11th to 20thNight
14%6%26%38%16%1
348
21st to endNight
12%427%39%16%1
434
August1st to 10thNight
16%326%37%18%1
537
11th to 20thNight
17%423%33%21%2
534
21st to endNight
21%6%25%29%15%3
616
September1st to 10thNight
19%6%27%29%18%1
720
11th to 20thNight
21%8%25%28%16%2
720
21st to endNight
24%6%27%28%14%2
720
October1st to 10thNight
26%11%26%28%8%1
720
11th to 20thNight
36%9%27%20%8%1
720
21st to endNight
37%11%25%22%41
792
November1st to 10thNight
29%11%32%22%5%1
740
11th to 20thNight
30%14%29%20%7%
760
21st to endNight
33%13%28%19%5%1
760
December1st to 10thNight
34%13%31%16%5%1
760
11th to 20thNight
29%14%33%17%5%1
893
21st to endNight
31%14%29%20%5%1
1045
Page generated at 2024-01-10 01:25:01. Version ac07

Copyright 2024 Attilla Danko


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