Grand Manan Island
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Grand Manan Island clear sky chart from 2005-11-06 to 2024-01-15.

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
30%
23292
13%
74825
7%
23237
37%
23237
15%
54820

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
14%
823
10%
2781
3%
820
22%
820
8%
2179
January11th to 20thNight
14%
739
8%
2583
1%
739
21%
739
6%
2129
January21st to endNight
15%
792
11%
2598
3%
792
25%
792
9%
2032
February1st to 10thNight
16%
720
10%
2340
3%
720
26%
720
9%
1833
February11th to 20thNight
16%
703
10%
2276
2%
700
26%
700
8%
1778
February21st to endNight
22%
592
15%
1778
4%
592
35%
592
14%
1311
March1st to 10thNight
19%
720
16%
2070
5%
720
31%
720
15%
1549
March11th to 20thNight
25%
720
13%
1980
5%
720
31%
720
15%
1492
March21st to endNight
28%
792
18%
2178
8%
792
37%
792
20%
1552
April1st to 10thNight
23%
662
13%
1873
4%
662
30%
662
16%
1397
April11th to 20thNight
32%
534
18%
1598
10%
534
38%
534
21%
1128
April21st to endNight
30%
540
13%
1620
7%
540
35%
540
17%
1190
May1st to 10thNight
37%
540
15%
1620
9%
540
42%
540
19%
1156
May11th to 20thNight
35%
532
14%
1541
10%
532
40%
532
18%
1136
May21st to endNight
42%
570
12%
1538
10%
569
45%
569
21%
1141
June1st to 10thNight
36%
360
10%
1260
10%
360
40%
360
13%
946
June11th to 20thNight
42%
360
13%
1260
14%
360
45%
360
17%
880
June21st to endNight
42%
360
9%
1260
11%
360
44%
360
13%
950
July1st to 10thNight
45%
350
9%
1225
13%
350
46%
350
14%
903
July11th to 20thNight
47%
348
9%
1309
13%
348
48%
348
14%
938
July21st to endNight
46%
541
11%
1625
12%
511
48%
511
17%
1190
August1st to 10thNight
55%
538
11%
1600
10%
534
55%
534
21%
1142
August11th to 20thNight
48%
532
12%
1596
9%
532
50%
532
17%
1170
August21st to endNight
54%
594
19%
1782
15%
594
55%
594
25%
1192
September1st to 10thNight
55%
600
18%
1846
15%
600
58%
600
27%
1164
September11th to 20thNight
48%
720
20%
1980
15%
720
52%
720
29%
1280
September21st to endNight
46%
720
23%
1980
15%
720
52%
720
29%
1295
October1st to 10thNight
44%
720
20%
2107
13%
720
50%
720
25%
1379
October11th to 20thNight
37%
720
20%
2160
11%
720
46%
720
22%
1448
October21st to endNight
26%
792
15%
2479
7%
792
34%
792
16%
1780
November1st to 10thNight
29%
740
16%
2407
8%
740
38%
740
17%
1663
November11th to 20thNight
25%
848
17%
2656
7%
848
36%
848
15%
1883
November21st to endNight
22%
850
11%
2660
3%
850
30%
850
12%
1969
December1st to 10thNight
14%
850
8%
2660
2%
850
22%
850
9%
2163
December11th to 20thNight
12%
849
9%
3426
1%
849
20%
849
6%
2761
December21st to endNight
14%
921
7%
5173
1%
907
24%
907
5%
3721

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
20%9%36%5%3445%7%35%
74661
Night
21%10%46%6%3445%6%31%
75111
TransparencyDay
51%5%12%20%11%1
74366
Night
55%6%10%18%10%1
74941
SeeingDay
24%7%22%30%15%3
15164
Night
26%10%25%26%11%1
23307

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
19%13%5%8%7%44445%26%
1379
11th to 20thDay
23%13%5%8%6%46%45%421%
1472
21st to endDay
16%9%48%8%6%6%46%6%27%
1755
February1st to 10thDay
21%11%5%6%6%45%47%7%24%
1620
11th to 20thDay
18%10%47%6%5%7%5%47%27%
1573
21st to endDay
13%11%47%6%36%5%6%5%33%
1476
March1st to 10thDay
16%12%5%7%6%45%446%32%
1886
11th to 20thDay
17%8%36%5%3445%7%37%
1980
21st to endDay
18%9%46%434446%38%
2178
April1st to 10thDay
21%9%5%7%4245%46%32%
2083
11th to 20thDay
21%9%25%42235%7%40%
2312
21st to endDay
22%9%25%5%3345%7%36%
2340
May1st to 10thDay
23%9%37%435%45%7%31%
2340
11th to 20thDay
21%8%35%433446%40%
2352
21st to endDay
21%9%36%5%245%5%8%33%
2750
June1st to 10thDay
24%8%46%5%335%47%32%
2700
11th to 20thDay
22%8%45%42445%7%36%
2700
21st to endDay
26%9%46%43445%6%30%
2700
July1st to 10thDay
17%9%5%6%5%345%6%8%33%
2700
11th to 20thDay
17%9%36%5%3446%9%33%
2605
21st to endDay
17%10%35%5%25%46%8%33%
2578
August1st to 10thDay
13%9%36%5%35%5%6%9%38%
2327
11th to 20thDay
17%9%35%5%35%6%5%7%35%
2304
21st to endDay
15%6%2443345%7%46%
2574
September1st to 10thDay
12%6%25%5%2345%8%47%
2112
11th to 20thDay
16%6%24333347%48%
1980
21st to endDay
18%7%24423347%45%
1980
October1st to 10thDay
16%6%35%5%3445%7%42%
1852
11th to 20thDay
19%6%25%5%335%5%7%41%
1800
21st to endDay
22%7%25%5%35%446%37%
1873
November1st to 10thDay
21%8%36%5%33436%38%
1671
11th to 20thDay
20%7%35%41446%7%38%
1522
21st to endDay
21%11%36%5%2445%6%33%
1520
December1st to 10thDay
26%9%48%7%44445%24%
1520
11th to 20thDay
26%11%49%7%445%5%5%20%
1716
21st to endDay
25%10%5%7%5%34445%27%
2431
January1st to 10thNight
21%13%5%7%7%45%45%6%24%
2781
11th to 20thNight
20%14%5%10%8%46%445%20%
2583
21st to endNight
15%11%49%7%6%6%6%7%7%24%
2598
February1st to 10thNight
21%10%49%7%35%45%7%25%
2340
11th to 20thNight
19%11%5%7%6%46%5%6%6%26%
2273
21st to endNight
16%9%5%7%7%445%5%5%33%
1778
March1st to 10thNight
17%12%47%6%35%446%32%
2061
11th to 20thNight
19%9%48%7%45%45%6%29%
1979
21st to endNight
18%9%46%5%345%47%35%
2178
April1st to 10thNight
25%10%36%5%3435%5%31%
1873
11th to 20thNight
23%9%36%5%3446%7%33%
1598
21st to endNight
29%8%35%5%3435%7%28%
1620
May1st to 10thNight
22%10%45%5%24446%34%
1620
11th to 20thNight
26%8%36%445%345%31%
1540
21st to endNight
22%9%36%5%3446%7%31%
1537
June1st to 10thNight
27%9%36%7%4345%7%25%
1260
11th to 20thNight
23%9%46%5%3435%5%33%
1260
21st to endNight
29%10%36%5%24446%27%
1260
July1st to 10thNight
17%14%6%7%5%3446%8%26%
1260
11th to 20thNight
21%11%5%6%5%25%5%6%7%27%
1352
21st to endNight
22%12%45%5%245%5%7%27%
1721
August1st to 10thNight
15%9%37%6%45%6%6%9%31%
1612
11th to 20thNight
18%12%45%6%35%46%7%30%
1596
21st to endNight
16%9%46%5%3335%7%40%
1782
September1st to 10thNight
15%9%34434348%43%
1846
11th to 20thNight
17%8%25%433446%44%
1980
21st to endNight
19%7%25%423347%43%
1980
October1st to 10thNight
19%6%25%5%245%47%40%
2107
11th to 20thNight
18%7%25%5%245%5%8%39%
2160
21st to endNight
24%9%35%433445%35%
2479
November1st to 10thNight
21%7%25%5%345%5%6%37%
2407
11th to 20thNight
19%9%35%5%35%5%5%7%34%
2656
21st to endNight
20%10%46%6%345%5%7%30%
2660
December1st to 10thNight
28%13%48%6%34446%22%
2660
11th to 20thNight
27%11%37%7%445%5%5%21%
3478
21st to endNight
25%12%45%5%34446%29%
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
63%5%12%13%7%1
1380
11th to 20thDay
69%5%10%12%41
1472
21st to endDay
63%5%10%15%7%
1755
February1st to 10thDay
61%7%12%13%6%
1620
11th to 20thDay
60%7%12%15%6%1
1581
21st to endDay
51%6%13%19%8%2
1476
March1st to 10thDay
55%410%19%9%2
1890
11th to 20thDay
47%5%12%19%15%2
1980
21st to endDay
46%6%10%21%14%3
2178
April1st to 10thDay
52%5%9%16%16%3
2083
11th to 20thDay
45%412%24%14%2
2312
21st to endDay
48%5%9%21%14%2
2340
May1st to 10thDay
53%5%9%18%12%2
2340
11th to 20thDay
46%410%24%14%2
2356
21st to endDay
50%6%13%20%10%1
2750
June1st to 10thDay
53%5%11%21%9%1
2700
11th to 20thDay
49%5%11%19%15%2
2700
21st to endDay
57%6%10%16%10%1
2700
July1st to 10thDay
51%5%13%18%11%1
2625
11th to 20thDay
51%6%13%21%9%1
2525
21st to endDay
50%5%15%21%8%
2434
August1st to 10thDay
45%8%13%24%10%
2314
11th to 20thDay
50%6%13%20%10%
2304
21st to endDay
39%5%13%25%16%1
2574
September1st to 10thDay
39%5%12%25%18%1
2112
11th to 20thDay
38%5%11%27%17%3
1980
21st to endDay
41%410%29%16%1
1980
October1st to 10thDay
41%7%12%26%15%
1852
11th to 20thDay
42%5%15%28%10%
1800
21st to endDay
48%6%13%21%12%1
1873
November1st to 10thDay
50%5%11%21%11%1
1671
11th to 20thDay
47%6%13%22%10%1
1522
21st to endDay
56%5%15%18%5%
1520
December1st to 10thDay
64%7%11%14%41
1520
11th to 20thDay
68%6%8%12%5%
1716
21st to endDay
61%7%11%13%7%1
2431
January1st to 10thNight
64%6%11%15%5%
2781
11th to 20thNight
68%7%9%11%4
2583
21st to endNight
63%6%11%15%5%
2598
February1st to 10thNight
62%6%11%13%7%1
2340
11th to 20thNight
61%7%8%15%7%1
2276
21st to endNight
55%6%11%17%11%1
1778
March1st to 10thNight
55%6%9%16%12%2
2070
11th to 20thNight
56%5%11%13%13%2
1980
21st to endNight
49%5%9%21%13%2
2178
April1st to 10thNight
55%5%8%14%13%4
1873
11th to 20thNight
51%410%20%14%1
1598
21st to endNight
56%5%8%16%13%2
1620
May1st to 10thNight
53%49%19%13%1
1620
11th to 20thNight
55%5%8%18%12%2
1541
21st to endNight
53%5%11%20%10%1
1538
June1st to 10thNight
59%6%9%19%7%1
1260
11th to 20thNight
52%5%9%21%11%2
1260
21st to endNight
59%6%7%17%7%4
1260
July1st to 10thNight
56%8%10%17%10%
1225
11th to 20thNight
55%6%12%15%10%1
1309
21st to endNight
55%5%11%19%8%1
1625
August1st to 10thNight
49%7%12%24%8%
1600
11th to 20thNight
55%6%13%18%8%
1596
21st to endNight
45%5%10%24%15%1
1782
September1st to 10thNight
40%6%10%27%16%1
1846
11th to 20thNight
41%49%25%19%2
1980
21st to endNight
42%48%27%18%1
1980
October1st to 10thNight
43%5%10%26%15%2
2107
11th to 20thNight
44%7%13%25%11%1
2160
21st to endNight
53%6%10%19%11%1
2479
November1st to 10thNight
50%6%13%19%12%1
2407
11th to 20thNight
51%7%12%18%11%1
2656
21st to endNight
56%7%14%17%6%1
2660
December1st to 10thNight
68%5%10%13%5%
2660
11th to 20thNight
65%6%10%13%5%1
3479
21st to endNight
58%7%13%15%6%1
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
33%11%33%16%6%1
180
11th to 20thDay
30%13%33%18%6%
168
21st to endDay
24%12%38%20%5%
347
February1st to 10thDay
29%14%34%19%4
340
11th to 20thDay
27%14%35%21%3
336
21st to endDay
19%13%34%27%7%
344
March1st to 10thDay
20%13%36%25%6%
420
11th to 20thDay
19%16%31%24%10%1
420
21st to endDay
23%9%31%26%9%2
462
April1st to 10thDay
27%11%28%27%6%1
420
11th to 20thDay
24%6%29%28%12%
412
21st to endDay
26%5%25%30%13%2
420
May1st to 10thDay
26%426%34%9%2
423
11th to 20thDay
24%220%35%17%2
498
21st to endDay
30%318%33%15%2
680
June1st to 10thDay
26%316%38%15%3
630
11th to 20thDay
24%315%34%21%3
630
21st to endDay
32%212%33%16%5%
630
July1st to 10thDay
26%210%38%20%3
620
11th to 20thDay
24%37%34%27%4
524
21st to endDay
19%211%38%26%4
488
August1st to 10thDay
16%410%36%29%6%
446
11th to 20thDay
25%37%35%25%5%
439
21st to endDay
19%212%33%28%5%
495
September1st to 10thDay
17%212%43%23%3
450
11th to 20thDay
22%318%29%22%5%
450
21st to endDay
20%219%35%18%6%
450
October1st to 10thDay
18%6%21%32%17%4
385
11th to 20thDay
20%427%29%16%4
360
21st to endDay
25%10%27%27%10%2
396
November1st to 10thDay
26%10%27%25%11%2
365
11th to 20thDay
25%15%31%20%8%
370
21st to endDay
29%15%31%20%5%1
370
December1st to 10thDay
32%10%33%20%5%
370
11th to 20thDay
33%13%34%17%3
228
21st to endDay
26%12%39%17%42
198
January1st to 10thNight
30%17%30%18%4
823
11th to 20thNight
30%17%31%17%5%
739
21st to endNight
22%18%36%19%4
792
February1st to 10thNight
28%19%31%19%3
720
11th to 20thNight
26%20%32%18%31
703
21st to endNight
20%17%33%24%5%1
592
March1st to 10thNight
24%14%36%24%2
720
11th to 20thNight
24%13%30%25%8%
720
21st to endNight
23%11%30%26%9%1
792
April1st to 10thNight
29%10%32%23%7%
662
11th to 20thNight
25%5%30%30%9%1
534
21st to endNight
31%327%26%11%2
540
May1st to 10thNight
28%324%32%12%2
540
11th to 20thNight
30%421%33%11%1
532
21st to endNight
26%220%34%15%2
570
June1st to 10thNight
31%417%31%15%1
360
11th to 20thNight
28%315%34%19%1
360
21st to endNight
33%29%37%17%3
360
July1st to 10thNight
27%310%35%24%1
350
11th to 20thNight
28%29%35%23%3
348
21st to endNight
29%28%38%22%2
541
August1st to 10thNight
19%38%40%27%3
538
11th to 20thNight
26%310%33%26%2
532
21st to endNight
18%211%39%25%5%
594
September1st to 10thNight
19%314%40%21%3
600
11th to 20thNight
22%418%29%22%5%
720
21st to endNight
23%320%30%18%5%
720
October1st to 10thNight
23%5%20%31%18%3
720
11th to 20thNight
20%8%27%27%15%3
720
21st to endNight
30%11%28%23%8%
792
November1st to 10thNight
25%11%29%24%10%1
740
11th to 20thNight
25%15%32%20%9%
848
21st to endNight
26%17%29%19%8%1
850
December1st to 10thNight
35%13%30%18%3
850
11th to 20thNight
31%19%32%14%3
850
21st to endNight
30%19%29%17%41
935
Page generated at 2024-01-12 08:31:49. Version ac07

Copyright 2024 Attilla Danko


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