Haines Junction
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Haines Junction clear sky chart from 2005-11-05 to 2017-09-22.

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
38%
13776
4%
46568
3%
13748
40%
13748
10%
37684

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
28%
763
4%
3057
4%
759
31%
759
6%
2575
January16th to endNight
28%
800
7%
3087
5%
800
31%
800
6%
2618
February1st to 15thNight
36%
731
5%
2617
4%
727
38%
727
8%
2160
February16th to endNight
39%
659
8%
2086
7%
659
40%
659
14%
1630
March1st to 15thNight
39%
697
10%
2187
9%
697
41%
697
13%
1709
March16th to endNight
44%
576
7%
2034
7%
576
45%
576
11%
1559
April1st to 15thNight
53%
539
6%
1654
4%
539
55%
539
17%
1183
April16th to endNight
56%
540
1%
1424
1%
540
57%
540
19%
1046
May1st to 15thNight
51%
404
0%
1125
0%
404
51%
404
19%
827
May16th to endNight
55%
281
0%
1025
0%
281
55%
281
19%
658
June1st to 15thNight
55%
180
0%
720
0%
180
55%
180
15%
490
June16th to endNight
50%
180
0%
720
0%
180
50%
180
12%
511
July1st to 15thNight
55%
170
0%
774
0%
170
55%
170
10%
558
July16th to endNight
56%
277
0%
967
0%
259
55%
259
15%
674
August1st to 15thNight
54%
494
0%
1210
0%
492
54%
492
24%
873
August16th to endNight
42%
573
1%
1559
1%
573
42%
573
13%
1263
September1st to 15thNight
40%
540
5%
1746
4%
540
41%
540
11%
1359
September16th to endNight
37%
581
7%
1877
7%
581
39%
581
11%
1486
October1st to 15thNight
34%
660
7%
1999
6%
660
36%
660
10%
1659
October16th to endNight
31%
735
3%
2456
2%
735
33%
735
7%
2123
November1st to 15thNight
28%
730
2%
2686
1%
730
29%
730
4%
2385
November16th to endNight
31%
750
4%
2880
4%
750
32%
750
5%
2493
December1st to 15thNight
30%
924
4%
3222
3%
924
31%
924
5%
2828
December16th to endNight
30%
992
4%
3456
3%
992
32%
992
5%
3017

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
7%9%5%10%8%5%7%6%7%8%23%
48393
Night
5%11%6%12%9%5%7%6%7%8%19%
46671
TransparencyDay
56%12%14%13%2
48001
Night
60%11%12%11%3
46568
SeeingDay
12%12%28%27%14%4
7656
Night
10%5%25%33%21%3
13781

By Month

Percentage Cloud Cover NW (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
213%10%17%13%6%6%6%7%6%9%
892
16th to endDay
214%7%17%12%6%8%5%8%8%8%
1137
February1st to 15thDay
28%6%16%11%6%8%5%8%8%16%
1247
16th to endDay
19%5%12%10%49%8%8%10%18%
1386
March1st to 15thDay
8%7%14%10%5%10%8%7%8%16%
1771
16th to endDay
17%6%14%10%6%9%7%8%9%19%
2190
April1st to 15thDay
29%5%10%9%5%7%8%8%8%23%
2291
16th to endDay
410%5%9%9%5%6%7%7%11%22%
2535
May1st to 15thDay
6%12%48%8%5%7%6%7%7%25%
2826
16th to endDay
5%6%36%7%47%6%8%10%33%
3084
June1st to 15thDay
10%5%36%6%46%6%7%9%33%
3240
16th to endDay
12%6%46%6%36%6%6%8%31%
3240
July1st to 15thDay
11%7%36%7%5%7%7%7%9%24%
3136
16th to endDay
13%7%26%7%36%6%7%9%27%
3135
August1st to 15thDay
8%7%36%6%37%6%7%8%33%
2742
16th to endDay
16%10%48%8%5%6%5%5%6%20%
2643
September1st to 15thDay
14%10%48%8%46%7%6%7%21%
2214
16th to endDay
11%14%49%7%47%7%6%7%19%
1895
October1st to 15thDay
10%13%5%9%8%46%6%6%7%22%
1631
16th to endDay
411%7%13%11%5%7%7%7%9%14%
1416
November1st to 15thDay
6%13%9%20%12%5%7%45%5%9%
1171
16th to endDay
213%7%17%12%7%9%6%6%8%7%
1074
December1st to 15thDay
414%9%16%13%6%7%5%9%7%6%
729
16th to endDay
111%8%18%18%7%9%5%8%5%5%
768
January1st to 15thNight
214%11%15%11%5%7%5%6%6%12%
3057
16th to endNight
211%7%16%12%7%8%7%6%7%10%
3087
February1st to 15thNight
38%7%14%12%6%9%7%8%8%13%
2605
16th to endNight
29%7%14%9%47%6%7%10%19%
2086
March1st to 15thNight
110%7%12%10%7%8%6%5%7%23%
2187
16th to endNight
29%7%12%9%47%6%6%8%23%
2029
April1st to 15thNight
16%49%8%5%7%7%7%10%31%
1654
16th to endNight
17%47%6%48%7%10%11%30%
1424
May1st to 15thNight
47%25%6%37%7%9%11%32%
1124
16th to endNight
5%426%6%36%6%8%12%36%
1025
June1st to 15thNight
10%6%26%5%36%6%8%10%33%
720
16th to endNight
9%5%47%5%5%6%7%8%9%30%
720
July1st to 15thNight
9%5%35%7%5%7%6%7%10%30%
822
16th to endNight
11%5%24446%6%10%12%31%
1034
August1st to 15thNight
5%3245%36%6%8%12%40%
1216
16th to endNight
14%9%36%5%46%6%7%8%26%
1559
September1st to 15thNight
10%8%27%8%47%6%7%8%27%
1746
16th to endNight
9%13%48%7%45%5%7%7%24%
1877
October1st to 15thNight
11%15%49%6%47%5%5%6%24%
1999
16th to endNight
5%15%8%14%9%5%7%6%5%8%14%
2456
November1st to 15thNight
5%14%8%18%12%5%5%7%5%7%9%
2686
16th to endNight
312%8%15%12%7%9%6%6%7%9%
2880
December1st to 15thNight
5%15%8%15%12%5%7%6%7%6%9%
3222
16th to endNight
313%7%17%14%6%7%7%7%7%6%
3456

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
72%8%9%7%2
892
16th to endDay
70%9%7%10%2
1137
February1st to 15thDay
62%10%7%13%5%
1247
16th to endDay
55%10%12%12%9%
1386
March1st to 15thDay
58%10%10%12%6%
1771
16th to endDay
58%13%9%11%6%
2190
April1st to 15thDay
54%13%15%14%2
2291
16th to endDay
54%14%16%12%2
2535
May1st to 15thDay
56%11%14%13%3
2826
16th to endDay
44%12%18%18%5%
3088
June1st to 15thDay
46%14%17%18%3
3240
16th to endDay
49%13%15%18%2
3240
July1st to 15thDay
52%15%17%12%1
2955
16th to endDay
50%15%19%13%1
2939
August1st to 15thDay
46%13%19%17%3
2723
16th to endDay
63%12%12%10%
2643
September1st to 15thDay
60%13%14%11%
2214
16th to endDay
61%13%13%12%
1895
October1st to 15thDay
62%13%10%11%2
1631
16th to endDay
63%16%12%6%1
1416
November1st to 15thDay
75%9%7%6%1
1171
16th to endDay
72%10%8%6%2
1074
December1st to 15thDay
72%12%48%1
729
16th to endDay
76%9%47%1
768
January1st to 15thNight
69%8%8%8%3
3057
16th to endNight
68%10%8%9%2
3087
February1st to 15thNight
62%12%8%12%3
2617
16th to endNight
57%9%12%12%8%
2086
March1st to 15thNight
58%8%9%14%7%1
2187
16th to endNight
54%12%13%12%6%
2034
April1st to 15thNight
45%12%18%18%4
1654
16th to endNight
43%14%18%20%2
1424
May1st to 15thNight
44%14%17%19%4
1125
16th to endNight
38%13%16%24%8%
1025
June1st to 15thNight
45%11%22%17%2
720
16th to endNight
47%14%19%18%
720
July1st to 15thNight
47%16%18%15%1
774
16th to endNight
40%18%29%11%1
967
August1st to 15thNight
35%18%26%16%3
1210
16th to endNight
54%15%19%10%
1559
September1st to 15thNight
52%15%17%13%
1746
16th to endNight
56%12%16%13%1
1877
October1st to 15thNight
62%11%10%11%3
1999
16th to endNight
68%11%11%7%1
2456
November1st to 15thNight
73%11%8%6%1
2686
16th to endNight
70%11%8%7%2
2880
December1st to 15thNight
71%10%5%9%1
3222
16th to endNight
71%9%7%8%1
3456

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%10%36%26%16%
30
16th to endDay
46%21%41%18%9%
99
February1st to 15thDay
6%5%26%35%20%5%
236
16th to endDay
3424%33%16%17%
211
March1st to 15thDay
5%11%32%26%13%10%
240
16th to endDay
211%24%32%21%6%
270
April1st to 15thDay
6%16%29%27%16%3
387
16th to endDay
10%13%30%30%13%2
450
May1st to 15thDay
13%16%34%23%9%2
468
16th to endDay
7%14%34%28%12%3
521
June1st to 15thDay
13%10%28%32%13%1
675
16th to endDay
14%8%28%29%17%2
675
July1st to 15thDay
14%9%26%28%17%3
549
16th to endDay
13%11%29%28%15%1
515
August1st to 15thDay
9%14%28%27%14%4
494
16th to endDay
21%17%32%22%5%
523
September1st to 15thDay
19%17%28%19%10%4
369
16th to endDay
22%17%24%16%13%4
263
October1st to 15thDay
17%16%23%21%11%9%
225
16th to endDay
9%6%24%30%22%7%
240
November1st to 15thDay
10%10%24%34%16%3
93
16th to endDay
110%21%18%31%16%
60
December1st to 15thDay
6%3332%19%35%
31
16th to endDay
36%12%34%31%12%
32
January1st to 15thNight
7%5%26%39%16%4
763
16th to endNight
8%5%32%34%16%3
800
February1st to 15thNight
6%5%29%39%16%2
734
16th to endNight
6%5%28%35%20%4
659
March1st to 15thNight
6%7%28%34%20%2
697
16th to endNight
5%422%32%29%4
576
April1st to 15thNight
3322%34%31%4
539
16th to endNight
5%323%33%30%3
540
May1st to 15thNight
10%8%20%27%31%1
405
16th to endNight
6%321%37%29%1
282
June1st to 15thNight
12%18%45%23%
180
16th to endNight
11%421%44%17%
180
July1st to 15thNight
10%222%40%24%
170
16th to endNight
12%5%19%33%28%
277
August1st to 15thNight
7%426%36%23%2
494
16th to endNight
21%5%22%31%17%1
573
September1st to 15thNight
15%8%27%29%16%3
540
16th to endNight
19%7%25%25%18%3
581
October1st to 15thNight
20%6%26%28%15%2
660
16th to endNight
12%5%27%30%21%2
735
November1st to 15thNight
12%5%25%35%16%4
730
16th to endNight
8%7%25%29%23%4
750
December1st to 15thNight
12%5%23%31%20%7%
924
16th to endNight
10%422%31%23%6%
992
Page generated at 2017-09-23 03:43:47. Version ac04

Copyright 2017 A. Danko


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