Campbell River
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Campbell River 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
32%
14463
8%
46710
5%
14434
36%
14434
12%
35533

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
24%
750
8%
2686
7%
746
27%
746
7%
2240
January16th to endNight
27%
799
5%
2813
5%
799
29%
799
7%
2348
February1st to 15thNight
25%
700
7%
2288
5%
700
28%
700
6%
1912
February16th to endNight
32%
632
11%
2053
9%
632
35%
632
12%
1536
March1st to 15thNight
23%
720
5%
2046
3%
720
25%
720
8%
1727
March16th to endNight
26%
768
7%
2112
4%
768
28%
768
9%
1748
April1st to 15thNight
32%
635
7%
1724
2%
635
36%
635
12%
1364
April16th to endNight
27%
540
9%
1620
5%
540
33%
540
12%
1242
May1st to 15thNight
36%
371
10%
1452
10%
371
43%
371
13%
989
May16th to endNight
32%
375
5%
1343
4%
374
34%
374
11%
974
June1st to 15thNight
34%
360
2%
1260
1%
360
34%
360
17%
861
June16th to endNight
35%
360
3%
1260
0%
360
35%
360
13%
904
July1st to 15thNight
46%
340
5%
1190
1%
340
49%
340
25%
685
July16th to endNight
53%
376
10%
1239
9%
354
61%
354
32%
652
August1st to 15thNight
61%
486
12%
1552
14%
484
64%
484
33%
863
August16th to endNight
51%
573
15%
1719
10%
573
56%
573
27%
1054
September1st to 15thNight
57%
685
19%
1755
10%
685
61%
685
37%
1069
September16th to endNight
38%
656
13%
1823
7%
656
42%
656
18%
1313
October1st to 15thNight
38%
660
8%
1980
7%
660
40%
660
15%
1434
October16th to endNight
27%
704
5%
2230
4%
704
30%
704
9%
1811
November1st to 15thNight
21%
700
5%
2450
4%
700
24%
700
5%
2094
November16th to endNight
22%
723
7%
2535
4%
723
27%
723
6%
2089
December1st to 15thNight
24%
750
5%
2700
3%
750
27%
750
7%
2219
December16th to endNight
23%
800
6%
2880
4%
800
26%
800
6%
2405

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%8%35%5%345%5%6%31%
47996
Night
22%9%36%5%34445%29%
46854
Cloud CoverDay
24%7%25%424446%33%
47996
Night
28%7%25%5%34345%29%
46857
TransparencyDay
52%8%16%16%5%
47644
Night
58%6%14%14%5%
46710
SeeingDay
24%16%17%20%16%4
6412
Night
29%18%11%21%15%3
14468

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
29%14%5%5%5%35%43418%
1253
16th to endDay
31%13%37%5%25%34417%
1410
February1st to 15thDay
33%12%26%5%2444318%
1576
16th to endDay
20%11%37%5%25%5%6%7%24%
1421
March1st to 15thDay
28%13%48%435%5%4416%
1911
16th to endDay
24%11%5%7%7%36%445%19%
2112
April1st to 15thDay
21%10%47%7%35%46%7%20%
2219
16th to endDay
23%9%5%7%5%35%5%5%6%24%
2340
May1st to 15thDay
16%6%35%6%3446%7%35%
2499
16th to endDay
17%7%46%6%45%5%5%8%28%
2769
June1st to 15thDay
14%7%36%5%36%6%6%8%31%
2700
16th to endDay
16%7%38%7%36%6%5%6%27%
2700
July1st to 15thDay
11%413424347%51%
2700
16th to endDay
8%3124246%5%6%54%
2846
August1st to 15thDay
5%213325%5%5%6%58%
2400
16th to endDay
10%4234245%5%8%47%
2483
September1st to 15thDay
9%414424445%54%
2124
16th to endDay
21%7%35%434346%33%
1807
October1st to 15thDay
24%10%36%5%3444430%
1650
16th to endDay
32%10%46%423446%19%
1642
November1st to 15thDay
34%10%36%6%345%3416%
1408
16th to endDay
29%12%35%5%34445%21%
1422
December1st to 15thDay
27%12%5%7%5%2323424%
1260
16th to endDay
31%14%48%5%2444415%
1344
January1st to 15thNight
27%13%47%6%35%43420%
2686
16th to endNight
30%11%47%5%34446%17%
2813
February1st to 15thNight
30%12%36%5%3445%5%18%
2276
16th to endNight
21%11%35%434445%31%
2053
March1st to 15thNight
26%11%37%5%35%5%5%420%
2046
16th to endNight
22%8%37%7%5%8%5%5%5%20%
2108
April1st to 15thNight
20%10%5%6%6%35%35%7%25%
1724
16th to endNight
20%9%46%5%4345%6%29%
1620
May1st to 15thNight
17%6%35%5%35%5%46%33%
1451
16th to endNight
13%10%5%9%6%345%5%6%28%
1343
June1st to 15thNight
16%7%35%4245%5%7%36%
1260
16th to endNight
12%5%39%8%5%5%5%6%5%31%
1260
July1st to 15thNight
9%414335%446%52%
1260
16th to endNight
8%223324446%58%
1323
August1st to 15thNight
7%324423347%55%
1559
16th to endNight
10%4144235%5%9%48%
1719
September1st to 15thNight
9%2245%23346%56%
1755
16th to endNight
21%7%3442334439%
1823
October1st to 15thNight
20%9%25%433335%36%
1980
16th to endNight
35%9%35%433345%22%
2230
November1st to 15thNight
33%11%36%6%35%44416%
2450
16th to endNight
26%14%36%6%3444421%
2535
December1st to 15thNight
30%12%5%6%5%2433421%
2700
16th to endNight
31%12%36%5%34445%19%
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
39%10%35%6%1333318%
1253
16th to endDay
37%12%35%5%33335%16%
1410
February1st to 15thDay
39%9%26%42343418%
1576
16th to endDay
25%10%344345%6%6%25%
1421
March1st to 15thDay
36%9%46%425%5%4417%
1911
16th to endDay
28%10%46%5%36%5%45%19%
2112
April1st to 15thDay
25%8%36%5%345%5%6%23%
2219
16th to endDay
28%7%35%5%34445%26%
2340
May1st to 15thDay
19%5%35%5%2346%7%36%
2499
16th to endDay
19%6%35%5%35%45%7%31%
2769
June1st to 15thDay
17%5%245%35%5%5%8%36%
2700
16th to endDay
19%5%36%6%45%5%5%6%31%
2700
July1st to 15thDay
12%313314446%54%
2700
16th to endDay
9%31232345%6%57%
2846
August1st to 15thDay
6%113224348%60%
2400
16th to endDay
12%413324447%50%
2483
September1st to 15thDay
11%41331345%6%53%
2124
16th to endDay
27%6%2441245%6%34%
1807
October1st to 15thDay
29%8%25%424335%30%
1650
16th to endDay
40%9%35%312346%18%
1642
November1st to 15thDay
41%9%25%43443316%
1408
16th to endDay
37%8%445%3343322%
1422
December1st to 15thDay
32%11%46%32333424%
1260
16th to endDay
39%11%36%42343415%
1344
January1st to 15thNight
35%11%36%5%2432320%
2685
16th to endNight
37%8%25%424445%17%
2813
February1st to 15thNight
36%10%25%434345%18%
2276
16th to endNight
27%8%24423335%31%
2053
March1st to 15thNight
34%9%35%445%34420%
2046
16th to endNight
27%8%36%7%45%5%45%20%
2112
April1st to 15thNight
24%9%36%6%3435%7%25%
1724
16th to endNight
26%7%26%5%3445%5%29%
1620
May1st to 15thNight
20%6%35%6%345%46%34%
1451
16th to endNight
18%8%48%5%345%47%29%
1343
June1st to 15thNight
19%7%2442345%7%38%
1260
16th to endNight
14%5%37%8%46%46%6%31%
1260
July1st to 15thNight
11%32341445%5%52%
1260
16th to endNight
10%32232335%5%58%
1323
August1st to 15thNight
9%31342335%6%57%
1559
16th to endNight
13%2144235%5%7%49%
1719
September1st to 15thNight
9%214423346%57%
1755
16th to endNight
25%5%2442334439%
1823
October1st to 15thNight
25%7%245%22335%36%
1980
16th to endNight
41%7%24422235%23%
2230
November1st to 15thNight
43%7%35%5%3443316%
2450
16th to endNight
34%10%35%6%3433320%
2535
December1st to 15thNight
37%11%3442322422%
2700
16th to endNight
38%9%35%5%3323419%
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
73%5%7%9%3
1253
16th to endDay
72%6%8%9%1
1410
February1st to 15thDay
71%7%7%8%22
1576
16th to endDay
59%8%14%12%5%
1421
March1st to 15thDay
71%7%9%9%2
1911
16th to endDay
67%7%10%13%1
2112
April1st to 15thDay
62%8%13%12%3
2219
16th to endDay
59%8%13%12%5%
2340
May1st to 15thDay
45%9%19%19%5%
2499
16th to endDay
52%7%18%17%2
2773
June1st to 15thDay
45%10%21%18%31
2700
16th to endDay
52%9%18%15%3
2700
July1st to 15thDay
31%7%24%24%9%1
2541
16th to endDay
25%10%26%28%9%
2667
August1st to 15thDay
24%8%25%30%10%1
2382
16th to endDay
33%8%28%22%6%1
2483
September1st to 15thDay
32%7%20%25%13%1
2124
16th to endDay
51%8%15%16%7%
1807
October1st to 15thDay
57%7%12%15%6%
1650
16th to endDay
67%8%13%8%2
1642
November1st to 15thDay
74%6%8%6%2
1408
16th to endDay
67%7%8%11%4
1422
December1st to 15thDay
65%7%11%9%5%1
1260
16th to endDay
73%5%7%8%31
1344
January1st to 15thNight
71%5%9%8%5%
2686
16th to endNight
69%7%9%10%2
2813
February1st to 15thNight
69%7%8%9%31
2288
16th to endNight
57%6%13%16%5%
2053
March1st to 15thNight
68%7%11%9%3
2046
16th to endNight
66%6%11%12%2
2112
April1st to 15thNight
59%8%13%15%2
1724
16th to endNight
56%8%11%18%5%
1620
May1st to 15thNight
50%6%17%18%6%
1452
16th to endNight
54%7%19%14%3
1343
June1st to 15thNight
45%9%23%14%5%1
1260
16th to endNight
51%7%17%19%3
1260
July1st to 15thNight
33%7%23%22%12%
1190
16th to endNight
25%7%28%30%6%
1239
August1st to 15thNight
27%7%25%28%8%1
1552
16th to endNight
33%8%25%24%6%1
1719
September1st to 15thNight
28%6%19%29%14%
1755
16th to endNight
49%7%18%16%7%
1823
October1st to 15thNight
52%6%16%18%6%
1980
16th to endNight
66%6%14%9%3
2230
November1st to 15thNight
73%6%9%7%21
2450
16th to endNight
69%5%7%11%5%
2535
December1st to 15thNight
68%6%10%8%4
2700
16th to endNight
71%5%8%9%4
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
25%113%23%25%11%
60
16th to endDay
56%16%7%12%7%
124
February1st to 15thDay
42%17%8%16%11%2
236
16th to endDay
32%18%14%18%11%3
211
March1st to 15thDay
46%21%13%10%6%1
262
16th to endDay
36%23%17%11%8%2
288
April1st to 15thDay
29%21%19%17%7%4
269
16th to endDay
30%21%20%15%10%1
270
May1st to 15thDay
22%17%22%18%15%2
288
16th to endDay
17%17%20%21%18%4
484
June1st to 15thDay
16%23%18%24%15%1
495
16th to endDay
20%17%19%24%14%3
495
July1st to 15thDay
12%14%20%25%21%5%
475
16th to endDay
7%16%17%23%30%4
515
August1st to 15thDay
6%7%14%31%29%9%
324
16th to endDay
15%10%18%30%20%4
332
September1st to 15thDay
16%12%16%24%18%11%
300
16th to endDay
31%14%17%17%14%5%
255
October1st to 15thDay
35%12%16%17%16%2
255
16th to endDay
46%12%13%13%11%3
230
November1st to 15thDay
48%15%11%15%10%
60
16th to endDay
48%8%10%313%16%
60
December1st to 15thDay
53%120%6%10%8%
60
16th to endDay
39%7%9%28%10%4
64
January1st to 15thNight
37%21%7%16%12%3
750
16th to endNight
36%19%8%16%13%4
799
February1st to 15thNight
37%20%8%20%12%1
704
16th to endNight
28%21%9%21%15%3
632
March1st to 15thNight
35%23%11%14%12%2
720
16th to endNight
28%25%12%16%13%3
768
April1st to 15thNight
25%22%10%23%15%3
635
16th to endNight
25%23%14%22%12%1
540
May1st to 15thNight
22%20%13%19%18%5%
372
16th to endNight
20%21%16%24%15%2
375
June1st to 15thNight
18%19%20%21%17%2
360
16th to endNight
15%20%17%25%18%1
360
July1st to 15thNight
11%17%19%24%21%5%
340
16th to endNight
7%18%13%34%22%3
376
August1st to 15thNight
9%10%10%36%28%5%
486
16th to endNight
15%10%15%30%25%2
573
September1st to 15thNight
11%11%10%29%25%10%
685
16th to endNight
29%13%11%20%19%5%
656
October1st to 15thNight
29%14%10%24%17%3
660
16th to endNight
44%12%8%18%11%4
704
November1st to 15thNight
44%17%10%19%7%
700
16th to endNight
36%23%9%17%10%2
723
December1st to 15thNight
38%19%10%15%12%3
750
16th to endNight
38%21%10%18%9%
800
Page generated at 2017-09-13 04:39:11. Version ac04

Copyright 2017 A. Danko


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