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 2005-11-05 to 2018-11-30.

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%
16590
12%
51580
7%
16558
32%
16558
16%
37675

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%
974
7%
2910
3%
970
18%
970
8%
2417
January16th to endNight
20%
889
10%
2810
5%
889
25%
889
9%
2251
February1st to 15thNight
18%
762
10%
2482
4%
761
25%
761
10%
1924
February16th to endNight
16%
683
10%
2210
4%
683
23%
683
10%
1732
March1st to 15thNight
18%
780
12%
2165
5%
780
24%
780
14%
1661
March16th to endNight
28%
832
20%
2288
9%
832
37%
832
22%
1559
April1st to 15thNight
22%
746
14%
1933
5%
746
27%
746
18%
1442
April16th to endNight
28%
579
16%
1735
9%
579
34%
579
19%
1214
May1st to 15thNight
32%
465
17%
1635
11%
465
42%
465
20%
1056
May16th to endNight
31%
406
13%
1622
9%
406
42%
406
19%
990
June1st to 15thNight
38%
390
11%
1365
9%
390
44%
390
19%
906
June16th to endNight
37%
390
9%
1365
6%
390
43%
390
21%
878
July1st to 15thNight
45%
370
14%
1295
14%
370
50%
370
30%
724
July16th to endNight
50%
437
14%
1491
14%
413
54%
413
27%
866
August1st to 15thNight
43%
575
13%
1715
9%
572
47%
572
24%
1135
August16th to endNight
43%
637
19%
1879
12%
637
48%
637
27%
1208
September1st to 15thNight
44%
780
19%
1960
9%
780
48%
780
32%
1295
September16th to endNight
40%
777
18%
2168
12%
777
44%
777
28%
1432
October1st to 15thNight
31%
780
15%
2340
10%
780
38%
780
18%
1674
October16th to endNight
19%
832
11%
2533
5%
832
26%
832
11%
2028
November1st to 15thNight
23%
820
12%
2865
8%
820
29%
820
13%
2111
November16th to endNight
18%
840
9%
2938
5%
840
24%
840
9%
2322
December1st to 15thNight
15%
806
8%
2756
3%
806
22%
806
8%
2226
December16th to endNight
15%
1040
9%
3120
3%
1040
20%
1040
8%
2624

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%29%
52726
Night
18%11%47%6%34445%29%
51741
TransparencyDay
56%310%20%8%
52404
Night
56%310%19%8%
51581
SeeingDay
24%12%30%21%8%2
7355
Night
25%10%29%24%9%1
16594

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
21%18%5%10%6%3433418%
1358
16th to endDay
16%17%7%9%8%34446%17%
1762
February1st to 15thDay
9%17%6%10%11%5%6%5%3419%
1710
16th to endDay
16%18%6%10%6%4333422%
1545
March1st to 15thDay
17%13%6%7%6%2444427%
2113
16th to endDay
13%9%37%6%23345%38%
2288
April1st to 15thDay
22%10%46%5%23346%29%
2356
16th to endDay
22%8%35%323335%38%
2500
May1st to 15thDay
22%8%36%5%3335%6%32%
2646
16th to endDay
19%6%26%5%34247%35%
2842
June1st to 15thDay
18%8%46%5%35%5%5%6%30%
2925
16th to endDay
17%6%36%6%36%5%6%7%30%
2925
July1st to 15thDay
14%5%36%43445%9%37%
2925
16th to endDay
14%6%25%6%45%5%5%8%34%
2928
August1st to 15thDay
16%7%25%6%45%5%6%8%31%
2487
16th to endDay
17%7%35%5%345%48%34%
2662
September1st to 15thDay
19%7%26%5%24446%34%
2327
16th to endDay
22%6%25%5%24446%33%
2121
October1st to 15thDay
22%11%36%5%25%345%29%
1950
16th to endDay
30%16%36%5%23335%19%
2041
November1st to 15thDay
23%15%47%6%24436%22%
1651
16th to endDay
27%18%5%9%6%2333316%
1677
December1st to 15thDay
21%18%6%10%7%3344415%
1531
16th to endDay
18%18%9%11%7%4233416%
1456
January1st to 15thNight
20%18%7%9%7%3344317%
2910
16th to endNight
15%15%6%10%8%35%445%19%
2810
February1st to 15thNight
11%13%6%11%9%46%445%21%
2480
16th to endNight
15%18%6%9%7%3433421%
2210
March1st to 15thNight
16%13%7%8%6%34426%27%
2153
16th to endNight
13%9%36%5%24446%38%
2288
April1st to 15thNight
21%11%5%6%42344431%
1933
16th to endNight
21%7%26%5%245%46%33%
1735
May1st to 15thNight
18%6%26%42445%6%36%
1635
16th to endNight
15%8%25%42445%6%39%
1621
June1st to 15thNight
17%8%36%5%34446%36%
1365
16th to endNight
12%6%26%6%35%448%38%
1365
July1st to 15thNight
10%4245%235%5%8%46%
1365
16th to endNight
10%4245%2445%9%44%
1586
August1st to 15thNight
14%6%26%5%345%5%6%39%
1726
16th to endNight
13%7%27%42435%5%42%
1879
September1st to 15thNight
16%5%24323446%45%
1960
16th to endNight
16%8%245%24346%41%
2168
October1st to 15thNight
22%9%25%5%34445%32%
2340
16th to endNight
27%14%47%6%2432422%
2533
November1st to 15thNight
20%11%37%6%34445%27%
2865
16th to endNight
25%16%48%6%23345%19%
2938
December1st to 15thNight
21%18%6%9%6%3434417%
2756
16th to endNight
21%18%7%9%7%34345%14%
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
70%28%13%5%
1359
16th to endDay
68%35%15%6%
1762
February1st to 15thDay
68%38%13%5%
1712
16th to endDay
67%15%15%10%
1545
March1st to 15thDay
60%310%16%8%1
2124
16th to endDay
49%18%22%15%3
2288
April1st to 15thDay
56%37%19%11%1
2356
16th to endDay
50%27%23%14%2
2500
May1st to 15thDay
52%29%21%12%1
2646
16th to endDay
50%311%20%12%
2846
June1st to 15thDay
53%310%21%10%
2925
16th to endDay
51%412%20%9%1
2925
July1st to 15thDay
41%412%29%11%
2766
16th to endDay
48%413%27%7%
2760
August1st to 15thDay
48%316%21%8%
2474
16th to endDay
48%414%25%6%
2662
September1st to 15thDay
49%312%23%9%
2327
16th to endDay
51%314%24%5%
2121
October1st to 15thDay
57%311%19%7%
1950
16th to endDay
69%310%13%4
2041
November1st to 15thDay
63%312%13%6%
1651
16th to endDay
74%18%11%4
1677
December1st to 15thDay
72%38%13%3
1531
16th to endDay
73%17%12%4
1456
January1st to 15thNight
72%27%12%4
2910
16th to endNight
68%27%14%6%
2810
February1st to 15thNight
64%310%15%5%
2482
16th to endNight
66%27%15%7%
2210
March1st to 15thNight
61%29%15%8%2
2165
16th to endNight
46%39%22%15%2
2288
April1st to 15thNight
56%27%18%12%1
1933
16th to endNight
50%39%17%16%2
1735
May1st to 15thNight
47%29%24%14%2
1635
16th to endNight
44%313%22%14%1
1623
June1st to 15thNight
48%310%23%11%2
1365
16th to endNight
44%5%12%23%13%1
1365
July1st to 15thNight
33%415%31%12%2
1295
16th to endNight
37%318%29%9%
1491
August1st to 15thNight
43%6%16%24%9%
1715
16th to endNight
42%315%28%9%
1879
September1st to 15thNight
39%416%26%11%1
1960
16th to endNight
43%314%30%7%
2168
October1st to 15thNight
54%312%20%9%
2340
16th to endNight
67%210%14%5%
2533
November1st to 15thNight
59%313%17%5%
2865
16th to endNight
67%210%13%4
2938
December1st to 15thNight
70%29%13%3
2756
16th to endNight
73%25%11%6%
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
32%11%38%15%2
90
16th to endDay
35%7%27%21%7%
132
February1st to 15thDay
28%20%38%12%
135
16th to endDay
40%20%31%6%
120
March1st to 15thDay
25%17%27%24%4
309
16th to endDay
20%18%32%20%5%2
352
April1st to 15thDay
28%15%26%19%9%
330
16th to endDay
28%14%30%13%8%4
319
May1st to 15thDay
30%9%26%19%12%2
348
16th to endDay
23%13%31%23%6%2
395
June1st to 15thDay
22%14%31%24%6%1
570
16th to endDay
17%11%32%24%10%2
570
July1st to 15thDay
14%10%32%28%12%1
550
16th to endDay
15%7%32%27%11%5%
470
August1st to 15thDay
19%5%25%26%15%8%
358
16th to endDay
24%6%24%21%15%7%
396
September1st to 15thDay
22%7%25%25%13%5%
375
16th to endDay
26%8%28%23%8%4
374
October1st to 15thDay
28%14%31%16%8%1
375
16th to endDay
33%16%29%16%31
361
November1st to 15thDay
37%14%33%10%21
121
16th to endDay
42%10%31%15%
119
December1st to 15thDay
34%11%40%13%1
90
16th to endDay
30%19%35%11%21
96
January1st to 15thNight
30%13%31%18%6%
975
16th to endNight
25%12%28%23%9%1
889
February1st to 15thNight
19%13%36%23%5%1
764
16th to endNight
26%14%32%21%5%
683
March1st to 15thNight
25%17%31%19%5%
780
16th to endNight
17%13%33%24%8%1
832
April1st to 15thNight
28%14%29%21%6%
746
16th to endNight
26%12%28%21%9%1
579
May1st to 15thNight
21%7%29%29%9%1
465
16th to endNight
20%9%33%27%9%
407
June1st to 15thNight
23%6%24%34%11%
390
16th to endNight
17%7%27%31%14%1
390
July1st to 15thNight
11%432%38%11%
370
16th to endNight
12%326%39%16%1
437
August1st to 15thNight
17%324%32%20%1
575
16th to endNight
17%5%26%30%17%2
637
September1st to 15thNight
20%5%26%25%20%1
780
16th to endNight
21%6%26%29%13%2
777
October1st to 15thNight
28%9%27%25%8%1
780
16th to endNight
39%8%24%21%5%
832
November1st to 15thNight
27%13%29%21%7%
820
16th to endNight
35%12%26%19%5%
840
December1st to 15thNight
33%11%31%17%41
806
16th to endNight
32%13%28%20%4
1040
Page generated at 2018-12-01 11:35:37. Version ac04

Copyright 2018 A. Danko


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