Nakusp
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Nakusp clear sky chart from 2005-11-05 to

2017-09-12
.

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
30%
14901
7%
46611
5%
14870
32%
14870
12%
36391

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
13%
793
3%
2580
2%
790
15%
790
4%
2333
January16th to endNight
17%
768
3%
2688
3%
768
18%
768
4%
2426
February1st to 15thNight
17%
702
4%
2438
3%
698
19%
698
6%
2131
February16th to endNight
22%
632
5%
1927
4%
632
24%
632
9%
1610
March1st to 15thNight
19%
720
2%
2160
1%
720
21%
720
7%
1860
March16th to endNight
22%
768
6%
2018
1%
768
24%
768
11%
1682
April1st to 15thNight
31%
719
6%
1799
2%
719
33%
719
15%
1444
April16th to endNight
33%
504
8%
1584
6%
504
35%
504
15%
1168
May1st to 15thNight
42%
359
9%
1440
10%
359
47%
359
18%
928
May16th to endNight
44%
374
6%
1377
6%
374
45%
374
15%
958
June1st to 15thNight
38%
360
2%
1260
0%
360
39%
360
16%
910
June16th to endNight
42%
360
4%
1124
0%
360
42%
360
20%
789
July1st to 15thNight
62%
340
6%
1197
2%
340
63%
340
31%
669
July16th to endNight
64%
376
13%
1416
18%
354
69%
354
36%
677
August1st to 15thNight
74%
360
20%
1432
28%
358
78%
358
35%
699
August16th to endNight
61%
604
23%
1750
20%
604
63%
604
41%
965
September1st to 15thNight
57%
706
19%
1765
11%
706
59%
706
40%
1091
September16th to endNight
44%
656
16%
1807
11%
656
48%
656
26%
1220
October1st to 15thNight
35%
660
10%
1958
8%
660
38%
660
18%
1422
October16th to endNight
27%
704
6%
2288
5%
704
29%
704
12%
1801
November1st to 15thNight
11%
700
4%
2347
2%
700
13%
700
6%
2044
November16th to endNight
18%
876
2%
2676
0%
876
20%
876
5%
2397
December1st to 15thNight
12%
900
2%
2700
1%
900
13%
900
5%
2464
December16th to endNight
8%
960
1%
2880
0%
960
9%
960
3%
2703

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
13%11%48%7%45%5%5%6%26%
48063
Night
13%14%5%9%7%45%45%5%23%
46770
Cloud CoverDay
15%12%47%6%35%5%5%6%26%
48063
Night
15%14%5%7%6%35%45%6%24%
46774
TransparencyDay
58%8%13%13%5%
47726
Night
60%7%12%13%5%
46611
SeeingDay
19%16%29%24%8%
5978
Night
23%9%30%27%9%
14907

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
21%20%6%11%7%5%5%5%338%
1367
16th to endDay
13%19%7%11%11%5%445%5%9%
1536
February1st to 15thDay
14%17%5%12%9%45%45%6%14%
1426
16th to endDay
7%16%7%11%10%46%6%6%5%17%
1547
March1st to 15thDay
13%16%8%10%10%6%6%5%46%12%
1800
16th to endDay
13%16%7%10%8%5%6%5%5%6%13%
2205
April1st to 15thDay
12%13%6%10%8%5%7%5%6%7%17%
2149
16th to endDay
13%14%5%9%9%46%5%5%6%21%
2375
May1st to 15thDay
13%9%37%7%35%45%7%31%
2511
16th to endDay
15%9%49%8%36%5%5%6%23%
2734
June1st to 15thDay
22%9%47%7%46%446%21%
2700
16th to endDay
15%6%37%7%47%6%5%7%27%
2829
July1st to 15thDay
6%325%6%36%5%7%7%44%
2683
16th to endDay
6%3145%35%5%6%9%47%
2657
August1st to 15thDay
4315%5%445%7%8%49%
2520
16th to endDay
7%4245%345%6%9%46%
2450
September1st to 15thDay
8%5%26%5%35%446%45%
2114
16th to endDay
15%9%37%6%345%5%7%30%
1823
October1st to 15thDay
16%10%5%8%6%35%5%6%5%25%
1670
16th to endDay
24%11%5%9%7%34445%18%
1584
November1st to 15thDay
23%15%6%9%8%5%5%435%11%
1510
16th to endDay
16%17%7%10%10%46%445%11%
1269
December1st to 15thDay
14%20%9%11%10%5%6%5%437%
1260
16th to endDay
12%21%7%13%9%6%7%6%436%
1344
January1st to 15thNight
22%24%8%11%7%5%5%4324
2580
16th to endNight
16%20%9%16%9%45%3334
2688
February1st to 15thNight
15%22%6%13%7%35%44410%
2426
16th to endNight
9%19%7%11%10%5%6%5%5%6%11%
1927
March1st to 15thNight
13%18%7%10%9%45%45%5%12%
2160
16th to endNight
13%15%410%7%36%5%6%6%19%
2014
April1st to 15thNight
10%13%5%8%7%36%6%6%6%25%
1799
16th to endNight
12%10%48%7%345%6%8%29%
1584
May1st to 15thNight
9%8%26%5%46%5%5%8%38%
1439
16th to endNight
13%7%36%5%35%5%5%9%33%
1377
June1st to 15thNight
17%8%25%5%36%5%6%7%30%
1260
16th to endNight
10%6%35%6%46%6%5%9%35%
1124
July1st to 15thNight
4325%43445%7%52%
1269
16th to endNight
5%21333447%8%57%
1512
August1st to 15thNight
422441346%7%58%
1440
16th to endNight
431342336%6%59%
1750
September1st to 15thNight
7%4134245%46%54%
1765
16th to endNight
11%7%26%5%24447%42%
1807
October1st to 15thNight
12%8%38%6%35%46%6%32%
1958
16th to endNight
21%11%47%7%35%6%7%7%18%
2288
November1st to 15thNight
22%17%5%10%8%45%445%10%
2347
16th to endNight
17%20%9%11%10%45%4348%
2676
December1st to 15thNight
15%22%8%15%9%5%43336%
2700
16th to endNight
14%23%9%16%10%5%6%4233
2880

Percentage Cloud Cover SW (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
23%19%6%11%6%25%35%310%
1367
16th to endDay
17%19%7%10%7%35%5%5%5%11%
1536
February1st to 15thDay
17%17%8%8%7%45%345%16%
1426
16th to endDay
9%16%7%11%9%45%5%6%5%18%
1547
March1st to 15thDay
18%18%6%9%8%46%45%5%13%
1800
16th to endDay
15%19%6%9%8%35%46%6%13%
2205
April1st to 15thDay
13%16%6%8%8%47%5%5%6%17%
2149
16th to endDay
13%16%5%8%8%46%447%19%
2375
May1st to 15thDay
14%11%36%5%35%5%6%6%30%
2511
16th to endDay
15%11%48%8%45%5%5%7%22%
2734
June1st to 15thDay
24%10%48%7%45%446%20%
2700
16th to endDay
17%7%36%7%46%6%5%7%26%
2829
July1st to 15thDay
7%425%5%36%6%7%8%43%
2683
16th to endDay
7%313435%5%6%9%48%
2657
August1st to 15thDay
5%4145%345%7%8%49%
2520
16th to endDay
8%4244345%6%8%45%
2450
September1st to 15thDay
10%6%26%435%447%46%
2114
16th to endDay
16%8%37%5%3445%7%32%
1823
October1st to 15thDay
18%9%47%5%46%5%5%6%26%
1670
16th to endDay
25%12%37%5%35%5%45%20%
1584
November1st to 15thDay
28%15%5%8%7%4444412%
1510
16th to endDay
19%18%5%7%6%35%6%45%14%
1269
December1st to 15thDay
15%19%8%11%9%5%5%5%449%
1260
16th to endDay
14%24%7%11%8%5%6%445%6%
1344
January1st to 15thNight
25%24%7%8%6%344447%
2580
16th to endNight
17%21%7%11%7%47%6%437%
2688
February1st to 15thNight
18%21%6%11%8%34345%11%
2426
16th to endNight
11%21%8%9%7%36%5%5%7%14%
1927
March1st to 15thNight
17%20%6%9%6%35%5%5%5%14%
2160
16th to endNight
15%16%5%9%6%35%6%5%6%19%
2018
April1st to 15thNight
12%15%47%7%35%5%6%7%25%
1799
16th to endNight
14%10%46%6%25%46%8%29%
1584
May1st to 15thNight
9%8%35%6%46%5%6%8%37%
1439
16th to endNight
14%8%35%5%35%5%6%8%33%
1377
June1st to 15thNight
19%8%25%4346%5%6%32%
1260
16th to endNight
13%6%25%7%35%6%5%9%34%
1124
July1st to 15thNight
6%4135%35%46%6%52%
1269
16th to endNight
5%21232436%8%58%
1512
August1st to 15thNight
5%3123226%6%7%57%
1440
16th to endNight
6%31432435%7%57%
1750
September1st to 15thNight
9%41332346%5%55%
1765
16th to endNight
14%6%345%24448%42%
1807
October1st to 15thNight
16%9%37%5%3445%7%33%
1958
16th to endNight
23%12%36%5%35%6%5%7%21%
2288
November1st to 15thNight
26%19%5%8%6%33446%12%
2347
16th to endNight
20%20%6%9%6%47%5%448%
2676
December1st to 15thNight
16%24%8%12%8%44345%7%
2700
16th to endNight
15%25%9%12%8%5%6%4444
2880

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
77%6%8%5%1
1367
16th to endDay
72%6%11%6%2
1536
February1st to 15thDay
70%8%10%7%2
1426
16th to endDay
66%8%13%8%2
1547
March1st to 15thDay
74%7%11%5%
1800
16th to endDay
72%8%13%4
2205
April1st to 15thDay
68%7%14%7%1
2149
16th to endDay
65%8%14%9%1
2375
May1st to 15thDay
53%7%16%18%4
2511
16th to endDay
61%8%15%12%1
2738
June1st to 15thDay
66%7%9%11%3
2700
16th to endDay
56%8%11%15%6%
2829
July1st to 15thDay
38%8%16%18%13%3
2526
16th to endDay
33%7%17%23%16%1
2490
August1st to 15thDay
32%9%17%26%11%2
2503
16th to endDay
35%8%16%26%11%1
2450
September1st to 15thDay
39%6%14%27%11%
2114
16th to endDay
51%6%15%19%6%
1823
October1st to 15thDay
57%8%15%16%2
1670
16th to endDay
65%7%14%11%
1584
November1st to 15thDay
75%8%8%41
1510
16th to endDay
69%10%10%6%2
1269
December1st to 15thDay
76%7%7%6%1
1260
16th to endDay
80%8%7%2
1344
January1st to 15thNight
81%46%42
2580
16th to endNight
78%7%7%32
2688
February1st to 15thNight
74%7%8%5%3
2438
16th to endNight
66%8%13%8%2
1927
March1st to 15thNight
71%7%12%6%1
2160
16th to endNight
65%8%13%9%2
2018
April1st to 15thNight
57%9%18%10%3
1799
16th to endNight
52%9%20%14%3
1584
May1st to 15thNight
46%5%19%18%9%
1440
16th to endNight
49%9%19%19%2
1377
June1st to 15thNight
51%8%12%18%7%
1260
16th to endNight
46%9%14%21%7%
1124
July1st to 15thNight
32%5%16%25%15%3
1197
16th to endNight
23%6%18%27%22%1
1416
August1st to 15thNight
24%6%16%34%15%3
1432
16th to endNight
25%6%16%34%15%1
1750
September1st to 15thNight
30%6%14%30%15%2
1765
16th to endNight
41%7%16%23%9%1
1807
October1st to 15thNight
50%8%16%18%5%
1958
16th to endNight
61%7%15%13%1
2288
November1st to 15thNight
74%7%9%6%3
2347
16th to endNight
76%7%8%5%1
2676
December1st to 15thNight
79%7%7%5%
2700
16th to endNight
82%8%6%1
2880

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
8%10%38%26%13%3
60
16th to endDay
25%17%34%10%12%
64
February1st to 15thDay
18%25%32%17%5%
86
16th to endDay
18%18%34%20%8%
233
March1st to 15thDay
28%32%26%10%1
270
16th to endDay
25%25%31%16%1
288
April1st to 15thDay
22%24%26%21%3
269
16th to endDay
25%24%28%16%5%
270
May1st to 15thDay
23%18%28%24%4
288
16th to endDay
21%12%24%24%14%1
449
June1st to 15thDay
26%13%24%26%8%
495
16th to endDay
16%11%33%29%8%
624
July1st to 15thDay
10%9%25%40%13%
460
16th to endDay
12%11%40%25%7%1
327
August1st to 15thDay
7%11%28%38%10%2
315
16th to endDay
9%17%31%30%10%1
332
September1st to 15thDay
15%15%31%26%10%1
300
16th to endDay
19%20%29%20%9%
255
October1st to 15thDay
25%17%33%16%7%
236
16th to endDay
33%10%29%19%7%
96
November1st to 15thDay
37%12%35%12%1
77
16th to endDay
26%16%25%18%5%8%
60
December1st to 15thDay
23%18%26%16%11%3
60
16th to endDay
20%9%43%18%7%
64
January1st to 15thNight
37%12%27%17%4
795
16th to endNight
25%10%34%25%3
768
February1st to 15thNight
30%10%29%22%6%
704
16th to endNight
21%10%34%25%8%
632
March1st to 15thNight
26%15%33%19%5%
720
16th to endNight
23%11%37%21%5%
768
April1st to 15thNight
19%11%30%29%9%
719
16th to endNight
21%7%31%32%6%
504
May1st to 15thNight
13%8%30%35%11%
360
16th to endNight
18%5%24%36%14%
375
June1st to 15thNight
21%8%23%34%11%
360
16th to endNight
15%6%30%34%13%
360
July1st to 15thNight
8%320%50%16%
340
16th to endNight
6%223%47%20%
376
August1st to 15thNight
7%310%47%31%
360
16th to endNight
7%323%43%22%
604
September1st to 15thNight
10%423%35%24%
706
16th to endNight
19%5%27%31%15%
656
October1st to 15thNight
21%7%30%33%6%
660
16th to endNight
31%8%28%25%6%
704
November1st to 15thNight
36%12%33%12%3
700
16th to endNight
29%14%30%19%6%
876
December1st to 15thNight
28%12%36%19%3
900
16th to endNight
30%13%39%13%2
960
Page generated at 2017-09-13 04:39:04. Version ac04

Copyright 2017 A. Danko


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