Pangnirtung
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pangnirtung clear sky chart from 2005-11-05 to 2017-11-30.

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
0%
3210
0%
35021
0%
2930
0%
2930
15%
34072

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
0%
128
0%
2509
0%
104
0%
104
17%
2375
January16th to endNight
0%
137
0%
2198
0%
117
0%
117
21%
2257
February1st to 15thNight
0%
140
0%
1897
0%
102
0%
102
20%
1801
February16th to endNight
0%
72
0%
1516
0%
67
0%
67
21%
1445
March1st to 15thNight
0%
65
0%
1422
0%
56
0%
56
23%
1487
March16th to endNight
0%
158
0%
1429
0%
148
0%
148
17%
1555
April1st to 15thNight
0%
105
0%
1095
0%
97
0%
97
16%
1176
April16th to endNight
0%
65
0%
905
0%
57
0%
57
13%
978
May1st to 15thNight
0%
117
0%
755
0%
115
0%
115
9%
772
May16th to endNight
0%
64
0%
492
0%
63
0%
63
7%
494
June1st to 15thNight
0%
8
0%
172
0%
8
0%
8
3%
160
June16th to endNight0
0%
3800
0%
33
July1st to 15thNight
0%
16
0%
199
0%
16
0%
16
9%
164
July16th to endNight
0%
101
0%
536
0%
89
0%
89
16%
465
August1st to 15thNight
0%
130
0%
874
0%
128
0%
128
14%
760
August16th to endNight
0%
192
0%
1227
0%
189
0%
189
10%
1122
September1st to 15thNight
0%
250
0%
1405
0%
241
0%
241
12%
1328
September16th to endNight
0%
282
0%
1682
0%
273
0%
273
10%
1664
October1st to 15thNight
0%
249
0%
1735
0%
229
0%
229
15%
1717
October16th to endNight
0%
198
0%
2043
0%
184
0%
184
14%
2060
November1st to 15thNight
0%
164
0%
2416
0%
149
0%
149
14%
2273
November16th to endNight
0%
259
0%
2772
0%
230
0%
230
11%
2750
December1st to 15thNight
0%
164
0%
2765
0%
140
0%
140
14%
2600
December16th to endNight
0%
146
0%
2939
0%
128
0%
128
18%
2636

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
TransparencyDay
64%411%14%4
48938
Night
55%5%13%18%6%
47162
SeeingDay
21%49%21%26%17%
8477
Night
11%38%24%33%19%
14009

By Month

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
46%6%14%23%8%
410
16th to endDay
43%313%25%11%2
798
February1st to 15thDay
45%5%16%25%6%
1078
16th to endDay
46%5%13%19%11%1
1253
March1st to 15thDay
44%7%12%18%15%1
1732
16th to endDay
55%10%6%17%9%1
2204
April1st to 15thDay
61%8%5%14%8%1
2382
16th to endDay
71%5%312%6%
2737
May1st to 15thDay
75%35%11%4
3051
16th to endDay
80%36%8%1
3551
June1st to 15thDay
73%27%12%2
3750
16th to endDay
67%39%16%2
3902
July1st to 15thDay
59%418%15%1
3482
16th to endDay
59%5%21%12%
3288
August1st to 15thDay
62%6%20%9%
2971
16th to endDay
72%413%9%
2798
September1st to 15thDay
71%39%12%2
2288
16th to endDay
69%210%15%2
1971
October1st to 15thDay
58%212%18%6%
1662
16th to endDay
57%310%22%5%1
1413
November1st to 15thDay
55%414%22%4
1036
16th to endDay
65%48%14%6%
695
December1st to 15thDay
56%117%18%5%1
294
16th to endDay
46%418%22%6%1
192
January1st to 15thNight
49%5%15%19%8%1
3528
16th to endNight
45%6%12%24%9%2
3426
February1st to 15thNight
45%5%17%24%7%
2786
16th to endNight
43%6%17%19%10%1
2220
March1st to 15thNight
43%6%13%22%11%1
2226
16th to endNight
55%7%6%18%9%1
2020
April1st to 15thNight
54%7%7%19%10%
1574
16th to endNight
63%5%418%5%1
1229
May1st to 15thNight
72%46%12%2
900
16th to endNight
77%36%10%2
566
June1st to 15thNight
72%18%15%
207
16th to endNight
60%9%27%3
55
July1st to 15thNight
55%5%20%17%2
247
16th to endNight
58%423%12%
617
August1st to 15thNight
61%6%23%8%1
964
16th to endNight
68%316%10%1
1391
September1st to 15thNight
66%314%14%1
1672
16th to endNight
71%39%12%2
1988
October1st to 15thNight
60%212%17%5%1
2298
16th to endNight
58%310%19%7%
2811
November1st to 15thNight
57%315%18%4
3152
16th to endNight
63%49%16%5%
3590
December1st to 15thNight
57%314%19%4
3663
16th to endNight
47%6%19%19%6%1
4032

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
10%15%25%45%5%
20
16th to endDay
5%1330%41%16%
53
February1st to 15thDay
6%18%36%38%
60
16th to endDay
1311%26%40%16%
105
March1st to 15thDay
216%30%32%25%
252
16th to endDay
4214%23%31%23%
288
April1st to 15thDay
6%112%23%29%26%
314
16th to endDay
10%312%22%29%21%
450
May1st to 15thDay
19%417%25%23%10%
618
16th to endDay
18%5%11%25%24%14%
738
June1st to 15thDay
27%48%18%25%14%
855
16th to endDay
32%47%18%25%13%
855
July1st to 15thDay
25%46%17%26%20%
779
16th to endDay
26%47%18%22%20%
703
August1st to 15thDay
27%2419%25%20%
632
16th to endDay
36%5%8%19%18%12%
514
September1st to 15thDay
30%6%11%19%20%11%
315
16th to endDay
22%37%20%26%18%
303
October1st to 15thDay
17%311%25%28%12%
270
16th to endDay
12%310%22%31%20%
207
November1st to 15thDay
1113%31%35%17%
82
16th to endDay
11%13%8%28%26%11%
45
December1st to 15thDay
36%57%5%
19
January1st to 15thNight
318%20%36%28%
941
16th to endNight
319%25%37%22%
992
February1st to 15thNight
3310%23%34%25%
832
16th to endNight
33422%42%23%
642
March1st to 15thNight
116%32%33%24%
720
16th to endNight
6%213%27%35%15%
718
April1st to 15thNight
5%211%30%36%14%
539
16th to endNight
7%37%31%34%16%
366
May1st to 15thNight
20%310%32%24%7%
330
16th to endNight
22%5%6%29%31%5%
188
June1st to 15thNight
18%11%25%33%11%
27
July1st to 15thNight
30%6%13%39%9%
43
16th to endNight
32%46%13%29%13%
233
August1st to 15thNight
30%3216%32%15%
359
16th to endNight
36%4322%23%9%
428
September1st to 15thNight
33%5%8%24%23%5%
540
16th to endNight
30%46%21%27%10%
680
October1st to 15thNight
19%311%27%29%9%
730
16th to endNight
12%47%25%32%17%
816
November1st to 15thNight
7%28%26%36%18%
880
16th to endNight
9%6%9%23%29%21%
1021
December1st to 15thNight
5%29%25%33%24%
960
16th to endNight
318%23%34%27%
1024
Page generated at 2017-12-01 12:13:43. Version ac04

Copyright 2017 A. Danko


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