Moncton
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Moncton clear sky chart from 2005-11-05 to 2017-08-12.

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
21%
14763
13%
46361
5%
14718
30%
14718
15%
33160

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
12%
750
13%
2685
1%
746
26%
746
9%
1917
January16th to endNight
15%
773
18%
2542
3%
773
32%
773
14%
1718
February1st to 15thNight
15%
704
11%
2286
3%
701
25%
701
13%
1644
February16th to endNight
16%
631
11%
2039
2%
631
27%
631
10%
1538
March1st to 15thNight
16%
720
14%
1995
4%
720
25%
720
14%
1501
March16th to endNight
18%
768
15%
2112
4%
768
27%
768
15%
1572
April1st to 15thNight
17%
558
12%
1782
6%
558
25%
558
12%
1343
April16th to endNight
22%
540
14%
1620
6%
540
30%
540
17%
1154
May1st to 15thNight
24%
540
9%
1523
4%
540
29%
540
15%
1163
May16th to endNight
20%
561
10%
1496
2%
560
27%
560
16%
1124
June1st to 15thNight
23%
396
7%
1296
4%
396
27%
396
13%
974
June16th to endNight
29%
360
7%
1260
4%
360
33%
360
14%
902
July1st to 15thNight
32%
340
11%
1190
7%
340
40%
340
21%
764
July16th to endNight
28%
518
8%
1414
5%
485
32%
485
17%
1034
August1st to 15thNight
34%
528
9%
1575
6%
524
37%
524
18%
1139
August16th to endNight
33%
525
13%
1605
7%
525
39%
525
23%
1056
September1st to 15thNight
30%
503
16%
1658
9%
503
40%
503
23%
1060
September16th to endNight
34%
657
22%
1834
11%
657
43%
657
29%
1153
October1st to 15thNight
27%
660
19%
1980
8%
660
36%
660
21%
1310
October16th to endNight
17%
704
14%
2131
4%
704
27%
704
13%
1535
November1st to 15thNight
21%
727
13%
2439
6%
727
30%
727
14%
1736
November16th to endNight
19%
750
13%
2520
5%
750
29%
750
12%
1815
December1st to 15thNight
13%
750
13%
2520
2%
750
26%
750
10%
1836
December16th to endNight
10%
800
11%
2859
1%
800
23%
800
7%
2172

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%34446%30%
47615
Night
19%9%36%5%34446%32%
46526
TransparencyDay
53%5%11%18%9%
47298
Night
52%5%11%19%9%
46361
SeeingDay
25%17%30%18%6%
7014
Night
25%16%32%20%5%
14763

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
13%15%5%8%5%24345%31%
1253
16th to endDay
13%12%47%6%3345%6%32%
1680
February1st to 15thDay
15%11%47%5%3435%7%29%
1575
16th to endDay
15%14%6%9%5%335%46%26%
1432
March1st to 15thDay
17%14%5%8%5%34345%27%
1954
16th to endDay
17%12%6%8%5%2333432%
2112
April1st to 15thDay
19%12%47%7%34446%25%
2163
16th to endDay
23%10%35%423346%31%
2340
May1st to 15thDay
26%9%36%5%3334427%
2428
16th to endDay
24%10%36%5%2345%6%27%
2618
June1st to 15thDay
30%8%25%5%34346%24%
2674
16th to endDay
26%8%46%425%447%25%
2700
July1st to 15thDay
16%5%26%5%35%5%6%9%33%
2700
16th to endDay
17%7%37%6%46%5%6%8%25%
2639
August1st to 15thDay
19%6%35%6%45%45%8%30%
2288
16th to endDay
16%5%25%5%4445%7%38%
2245
September1st to 15thDay
19%6%25%424446%38%
1969
16th to endDay
18%5%14423236%47%
1796
October1st to 15thDay
19%9%25%313347%39%
1650
16th to endDay
22%8%46%5%34445%30%
1738
November1st to 15thDay
22%10%36%423446%32%
1419
16th to endDay
16%12%47%6%25%346%28%
1440
December1st to 15thDay
24%12%5%6%424345%28%
1440
16th to endDay
23%16%45%413236%27%
1362
January1st to 15thNight
15%11%5%5%7%3445%5%31%
2685
16th to endNight
15%10%46%5%33346%36%
2542
February1st to 15thNight
15%12%46%6%3445%6%30%
2285
16th to endNight
17%14%47%6%35%335%27%
2039
March1st to 15thNight
18%11%37%6%34336%28%
1983
16th to endNight
18%13%5%7%43323432%
2112
April1st to 15thNight
22%11%47%6%3344427%
1782
16th to endNight
21%11%3442435%434%
1620
May1st to 15thNight
24%10%25%5%3446%6%26%
1523
16th to endNight
19%9%36%5%3445%7%30%
1494
June1st to 15thNight
27%7%36%5%3445%7%26%
1296
16th to endNight
21%8%35%5%25%46%7%29%
1260
July1st to 15thNight
13%6%24435%6%7%10%36%
1260
16th to endNight
16%8%37%7%35%45%7%30%
1512
August1st to 15thNight
16%8%36%6%245%48%32%
1587
16th to endNight
13%6%25%4346%5%8%40%
1605
September1st to 15thNight
18%6%24423438%41%
1658
16th to endNight
13%5%24423345%50%
1834
October1st to 15thNight
17%6%25%424437%40%
1980
16th to endNight
24%9%36%423345%33%
2131
November1st to 15thNight
21%9%35%5%3345%5%32%
2439
16th to endNight
19%9%36%6%34346%33%
2520
December1st to 15thNight
22%10%36%5%3434430%
2520
16th to endNight
24%13%5%5%42333427%
2859

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
55%6%11%15%9%1
1254
16th to endDay
51%6%9%17%15%
1680
February1st to 15thDay
54%5%11%18%8%1
1578
16th to endDay
58%5%10%16%8%1
1432
March1st to 15thDay
59%48%16%9%1
1965
16th to endDay
56%49%18%9%2
2112
April1st to 15thDay
59%5%7%14%11%1
2163
16th to endDay
54%49%17%11%2
2340
May1st to 15thDay
59%47%17%9%
2428
16th to endDay
58%5%10%19%6%
2622
June1st to 15thDay
60%5%11%15%6%
2674
16th to endDay
57%6%11%16%6%
2700
July1st to 15thDay
44%7%16%20%10%
2541
16th to endDay
53%7%15%17%5%
2475
August1st to 15thDay
50%6%13%21%7%
2275
16th to endDay
43%7%17%23%7%
2245
September1st to 15thDay
46%6%14%20%11%
1969
16th to endDay
39%310%30%14%1
1796
October1st to 15thDay
45%5%11%27%9%
1650
16th to endDay
55%5%10%19%9%
1738
November1st to 15thDay
54%413%14%12%
1419
16th to endDay
56%6%12%15%9%
1440
December1st to 15thDay
58%6%11%16%6%
1440
16th to endDay
61%311%13%10%
1362
January1st to 15thNight
53%6%11%18%9%1
2685
16th to endNight
49%411%23%11%
2542
February1st to 15thNight
54%412%17%11%
2286
16th to endNight
59%410%14%9%1
2039
March1st to 15thNight
56%48%18%10%1
1995
16th to endNight
56%38%19%11%1
2112
April1st to 15thNight
58%48%13%11%2
1782
16th to endNight
52%310%17%14%
1620
May1st to 15thNight
57%5%10%17%7%
1523
16th to endNight
52%8%13%18%7%
1496
June1st to 15thNight
58%5%11%16%6%1
1296
16th to endNight
52%8%13%17%7%
1260
July1st to 15thNight
40%9%16%25%8%
1190
16th to endNight
51%7%15%17%7%
1414
August1st to 15thNight
49%8%14%20%6%
1575
16th to endNight
40%8%18%26%6%
1605
September1st to 15thNight
41%5%12%29%10%
1658
16th to endNight
37%414%29%13%
1834
October1st to 15thNight
44%411%28%10%
1980
16th to endNight
53%410%20%9%
2131
November1st to 15thNight
53%5%13%18%8%
2439
16th to endNight
54%5%13%17%8%
2520
December1st to 15thNight
56%5%11%20%6%
2520
16th to endNight
62%48%15%9%
2859

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%28%38%5%
60
16th to endDay
21%22%37%16%2
238
February1st to 15thDay
19%23%34%16%5%
236
16th to endDay
23%22%31%14%5%
214
March1st to 15thDay
24%26%31%15%11
270
16th to endDay
28%22%28%14%31
288
April1st to 15thDay
26%29%26%14%3
270
16th to endDay
25%24%31%12%5%1
270
May1st to 15thDay
34%18%22%17%5%1
384
16th to endDay
30%17%29%17%4
519
June1st to 15thDay
35%14%27%16%5%
495
16th to endDay
25%14%30%21%6%1
495
July1st to 15thDay
20%11%34%24%8%1
475
16th to endDay
21%9%32%26%10%
467
August1st to 15thDay
19%10%34%25%8%2
297
16th to endDay
16%12%33%26%10%1
268
September1st to 15thDay
20%9%40%21%7%
255
16th to endDay
19%12%37%23%5%2
251
October1st to 15thDay
25%11%28%18%12%3
225
16th to endDay
28%22%28%11%7%1
240
November1st to 15thDay
28%20%25%12%10%2
235
16th to endDay
25%21%31%14%6%
240
December1st to 15thDay
30%25%29%11%2
240
16th to endDay
36%29%21%10%1
82
January1st to 15thNight
23%24%31%15%3
750
16th to endNight
23%20%35%15%5%
773
February1st to 15thNight
23%19%37%16%3
704
16th to endNight
27%21%27%17%31
631
March1st to 15thNight
25%19%33%18%2
720
16th to endNight
25%17%31%17%7%
768
April1st to 15thNight
29%18%28%18%5%
558
16th to endNight
29%14%30%19%5%
540
May1st to 15thNight
30%14%28%20%6%
540
16th to endNight
24%13%37%19%4
561
June1st to 15thNight
29%7%32%25%5%
396
16th to endNight
22%8%33%27%7%
360
July1st to 15thNight
16%441%28%8%
340
16th to endNight
18%9%37%26%7%
518
August1st to 15thNight
20%5%32%27%12%1
528
16th to endNight
16%8%36%29%9%
525
September1st to 15thNight
20%10%33%28%6%
503
16th to endNight
16%11%35%28%7%
657
October1st to 15thNight
22%12%33%21%9%
660
16th to endNight
31%18%27%18%3
704
November1st to 15thNight
27%15%32%17%7%1
727
16th to endNight
24%22%28%19%5%
750
December1st to 15thNight
29%23%28%14%3
750
16th to endNight
34%23%25%13%31
800
Page generated at 2017-08-13 15:16:46. Version ac04

Copyright 2017 A. Danko


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