Gibsons
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Gibsons clear sky chart from 2005-11-06 to 2024-02-15.

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%
22725
9%
80919
8%
22599
41%
22599
13%
61067

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 10thNight
17%
843
8%
4698
6%
816
21%
816
4%
3904
January11th to 20thNight
25%
841
9%
4675
4%
820
27%
820
5%
3322
January21st to endNight
25%
866
5%
4912
7%
840
29%
840
4%
4373
February1st to 10thNight
25%
760
9%
2470
5%
760
30%
760
9%
2025
February11th to 20thNight
30%
718
10%
2331
7%
718
35%
718
11%
1830
February21st to endNight
27%
592
10%
1924
7%
592
33%
592
11%
1506
March1st to 10thNight
30%
720
8%
2083
6%
720
32%
720
12%
1678
March11th to 20thNight
30%
720
9%
1980
6%
720
31%
720
11%
1635
March21st to endNight
29%
792
7%
2139
3%
792
31%
792
10%
1813
April1st to 10thNight
37%
720
7%
1800
3%
720
39%
720
14%
1444
April11th to 20thNight
34%
592
12%
1660
6%
592
39%
592
16%
1272
April21st to endNight
39%
504
10%
1584
7%
504
43%
504
14%
1184
May1st to 10thNight
50%
360
12%
1440
17%
360
54%
360
18%
932
May11th to 20thNight
55%
354
11%
1416
18%
354
57%
354
17%
940
May21st to endNight
52%
388
7%
1454
10%
388
54%
388
16%
1003
June1st to 10thNight
48%
360
4%
1260
3%
360
49%
360
16%
897
June11th to 20thNight
53%
360
3%
1260
2%
360
53%
360
16%
913
June21st to endNight
62%
360
6%
1260
2%
360
63%
360
22%
808
July1st to 10thNight
69%
350
7%
1225
6%
350
69%
350
28%
725
July11th to 20thNight
74%
348
13%
1218
16%
348
75%
348
34%
646
July21st to endNight
80%
394
16%
1400
25%
372
83%
372
41%
658
August1st to 10thNight
77%
394
17%
1460
22%
392
79%
392
35%
728
August11th to 20thNight
79%
534
21%
1602
21%
534
80%
534
43%
850
August21st to endNight
65%
630
19%
1818
16%
630
66%
630
30%
1133
September1st to 10thNight
68%
720
19%
1800
12%
720
69%
720
39%
1114
September11th to 20thNight
52%
720
18%
1824
11%
720
54%
720
26%
1292
September21st to endNight
49%
720
16%
2048
11%
720
52%
720
23%
1424
October1st to 10thNight
48%
720
11%
2160
10%
720
51%
720
23%
1479
October11th to 20thNight
41%
720
11%
2160
10%
720
44%
720
16%
1613
October21st to endNight
30%
792
11%
2530
9%
792
35%
792
13%
1921
November1st to 10thNight
23%
740
6%
2590
5%
740
25%
740
8%
2134
November11th to 20thNight
25%
760
8%
2660
6%
760
29%
760
9%
2128
November21st to endNight
23%
760
8%
2660
4%
760
28%
760
8%
2144
December1st to 10thNight
31%
791
10%
2726
7%
791
35%
791
10%
2158
December11th to 20thNight
15%
850
3%
3516
2%
849
18%
849
5%
3080
December21st to endNight
14%
932
5%
5176
3%
905
20%
905
4%
4361

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
24%8%36%5%3445%6%33%
77852
Night
29%9%36%5%34446%29%
81177
TransparencyDay
52%10%13%16%7%1
77559
Night
58%7%12%15%7%1
81050
SeeingDay
23%6%20%27%20%4
14403
Night
31%6%17%24%18%4
22749

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 10thDay
44%10%36%5%24445%13%
2219
11th to 20thDay
30%13%36%5%35%346%22%
2199
21st to endDay
57%9%25%42333310%
2741
February1st to 10thDay
33%9%46%6%446%5%5%17%
1710
11th to 20thDay
28%10%36%4345%5%7%25%
1612
21st to endDay
24%9%48%7%46%5%5%6%25%
1332
March1st to 10thDay
30%9%46%6%345%5%6%21%
1873
11th to 20thDay
32%10%47%6%34345%21%
1980
21st to endDay
28%11%47%6%34435%26%
2216
April1st to 10thDay
25%10%37%5%45%5%6%6%24%
2160
11th to 20thDay
24%7%47%6%345%6%6%28%
2248
21st to endDay
22%9%46%5%35%45%6%31%
2376
May1st to 10thDay
16%6%36%6%35%46%7%38%
2520
11th to 20thDay
15%7%36%5%45%5%6%9%34%
2477
21st to endDay
17%7%36%6%345%5%8%35%
2819
June1st to 10thDay
21%7%36%6%35%45%8%33%
2700
11th to 20thDay
17%7%46%6%45%5%6%8%31%
2700
21st to endDay
15%425%5%35%5%5%8%42%
2700
July1st to 10thDay
10%5%25%5%2445%6%51%
2700
11th to 20thDay
9%42332446%7%55%
2700
21st to endDay
7%32342335%6%64%
2833
August1st to 10thDay
9%42442335%7%57%
2468
11th to 20thDay
7%5%25%32345%6%58%
2298
21st to endDay
10%5%25%5%345%5%8%49%
2538
September1st to 10thDay
11%6%35%43345%7%50%
2160
11th to 20thDay
18%6%35%424446%43%
2134
21st to endDay
23%6%2443446%8%37%
1912
October1st to 10thDay
26%6%3442445%7%35%
1800
11th to 20thDay
33%7%35%5%345%46%25%
1800
21st to endDay
34%9%35%43335%6%26%
1823
November1st to 10thDay
40%9%26%433435%20%
1488
11th to 20thDay
37%9%35%4235%36%23%
1520
21st to endDay
40%9%36%43444421%
1520
December1st to 10thDay
31%12%46%5%34445%22%
1449
11th to 20thDay
39%13%46%5%3343414%
1685
21st to endDay
44%12%47%5%2323313%
2442
January1st to 10thNight
39%11%47%6%3433415%
4726
11th to 20thNight
32%9%36%5%3445%7%22%
4699
21st to endNight
53%11%35%32333412%
4912
February1st to 10thNight
32%12%36%5%45%445%19%
2470
11th to 20thNight
28%11%45%5%34445%28%
2329
21st to endNight
27%11%46%5%34446%26%
1924
March1st to 10thNight
30%10%46%5%2445%5%24%
2083
11th to 20thNight
32%9%47%5%34345%23%
1979
21st to endNight
29%11%47%6%35%5%46%20%
2139
April1st to 10thNight
26%10%36%5%46%5%5%6%24%
1800
11th to 20thNight
21%9%38%6%345%5%6%29%
1660
21st to endNight
23%8%36%6%35%46%6%30%
1584
May1st to 10thNight
16%5%26%5%45%5%5%7%41%
1440
11th to 20thNight
16%6%36%5%46%5%7%9%34%
1416
21st to endNight
15%8%36%6%445%5%8%35%
1454
June1st to 10thNight
21%8%28%6%35%5%45%34%
1260
11th to 20thNight
16%8%46%6%35%6%5%8%33%
1260
21st to endNight
11%5%25%6%36%5%6%8%43%
1260
July1st to 10thNight
11%425%434445%53%
1260
11th to 20thNight
6%5%2432445%7%58%
1260
21st to endNight
6%313323446%65%
1482
August1st to 10thNight
7%314323445%64%
1468
11th to 20thNight
5%22332345%8%62%
1602
21st to endNight
10%425%5%35%5%6%8%47%
1818
September1st to 10thNight
9%423425%446%57%
1800
11th to 20thNight
20%6%35%42345%6%44%
1824
21st to endNight
21%7%25%5%33446%41%
2048
October1st to 10thNight
20%6%35%5%24347%41%
2160
11th to 20thNight
31%7%35%424446%32%
2160
21st to endNight
35%7%24423345%30%
2530
November1st to 10thNight
38%10%37%5%34335%20%
2590
11th to 20thNight
34%9%35%5%34345%25%
2660
21st to endNight
38%9%36%5%33345%22%
2660
December1st to 10thNight
32%11%46%435%446%23%
2726
11th to 20thNight
44%12%46%42334413%
3520
21st to endNight
45%14%46%42332315%
5214

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 10thDay
73%8%8%7%31
2219
11th to 20thDay
62%415%10%7%1
2220
21st to endDay
81%5%6%6%1
2741
February1st to 10thDay
68%10%8%8%33
1710
11th to 20thDay
60%10%9%14%6%1
1621
21st to endDay
60%12%12%10%5%2
1332
March1st to 10thDay
62%10%13%10%4
1873
11th to 20thDay
68%7%8%12%41
1980
21st to endDay
62%11%11%13%3
2216
April1st to 10thDay
62%12%12%10%4
2160
11th to 20thDay
56%11%12%13%8%
2248
21st to endDay
56%11%11%14%8%1
2376
May1st to 10thDay
46%14%15%18%7%1
2520
11th to 20thDay
47%13%15%19%5%
2480
21st to endDay
48%13%14%20%4
2820
June1st to 10thDay
51%11%16%14%5%2
2700
11th to 20thDay
51%15%16%13%4
2700
21st to endDay
41%12%18%18%9%2
2700
July1st to 10thDay
35%12%16%23%11%3
2626
11th to 20thDay
29%11%20%30%10%1
2619
21st to endDay
20%11%19%32%14%4
2675
August1st to 10thDay
29%12%17%29%12%2
2451
11th to 20thDay
27%10%20%26%14%3
2298
21st to endDay
34%12%19%27%6%1
2538
September1st to 10thDay
35%11%14%25%11%3
2160
11th to 20thDay
45%9%12%18%14%2
2134
21st to endDay
47%10%16%16%9%2
1912
October1st to 10thDay
49%9%16%17%9%
1800
11th to 20thDay
59%12%12%13%41
1800
21st to endDay
60%8%11%12%7%1
1823
November1st to 10thDay
67%8%10%9%5%1
1488
11th to 20thDay
67%8%9%9%5%2
1520
21st to endDay
67%8%6%11%7%1
1520
December1st to 10thDay
64%8%8%11%7%2
1449
11th to 20thDay
73%7%10%6%31
1688
21st to endDay
77%7%6%6%31
2442
January1st to 10thNight
73%6%6%11%31
4726
11th to 20thNight
60%6%16%11%6%1
4740
21st to endNight
79%5%5%8%21
4912
February1st to 10thNight
67%7%9%10%5%2
2470
11th to 20thNight
60%9%11%13%7%1
2331
21st to endNight
60%8%9%14%7%2
1924
March1st to 10thNight
61%9%13%12%5%
2083
11th to 20thNight
65%7%9%13%5%1
1980
21st to endNight
67%8%10%11%3
2139
April1st to 10thNight
60%8%13%15%4
1800
11th to 20thNight
55%9%11%15%9%2
1660
21st to endNight
55%9%12%15%10%
1584
May1st to 10thNight
42%10%16%22%8%1
1440
11th to 20thNight
45%9%18%20%6%1
1416
21st to endNight
48%9%16%21%5%
1454
June1st to 10thNight
53%7%16%17%5%3
1260
11th to 20thNight
50%10%17%17%5%
1260
21st to endNight
39%10%19%20%9%3
1260
July1st to 10thNight
34%9%15%25%14%4
1225
11th to 20thNight
27%8%22%29%12%2
1218
21st to endNight
19%9%15%33%20%5%
1400
August1st to 10thNight
24%8%17%29%18%3
1460
11th to 20thNight
21%9%23%26%16%5%
1602
21st to endNight
34%9%18%29%10%
1818
September1st to 10thNight
29%9%17%29%13%4
1800
11th to 20thNight
43%9%11%17%16%4
1824
21st to endNight
47%6%15%21%9%2
2048
October1st to 10thNight
44%8%16%19%12%1
2160
11th to 20thNight
55%7%14%17%6%
2160
21st to endNight
60%6%10%16%8%
2530
November1st to 10thNight
69%6%10%9%41
2590
11th to 20thNight
65%7%10%10%6%2
2660
21st to endNight
66%7%8%11%7%1
2660
December1st to 10thNight
64%6%10%12%6%1
2726
11th to 20thNight
76%7%7%5%5%1
3516
21st to endNight
75%5%8%8%41
5214

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 10thDay
43%11%18%15%8%5%
180
11th to 20thDay
42%13%16%16%12%1
180
21st to endDay
45%10%21%14%10%1
237
February1st to 10thDay
38%9%26%17%9%1
370
11th to 20thDay
34%6%26%23%8%2
348
21st to endDay
26%10%28%24%12%1
280
March1st to 10thDay
32%8%26%23%9%2
418
11th to 20thDay
31%10%20%24%13%2
420
21st to endDay
31%8%26%23%11%1
462
April1st to 10thDay
30%10%25%20%13%1
420
11th to 20thDay
29%7%26%22%15%2
412
21st to endDay
22%8%28%24%16%1
420
May1st to 10thDay
16%7%21%38%17%1
423
11th to 20thDay
17%416%31%28%3
448
21st to endDay
14%6%21%32%22%4
581
June1st to 10thDay
21%421%31%21%2
630
11th to 20thDay
17%5%24%32%19%3
630
21st to endDay
14%317%35%27%4
630
July1st to 10thDay
13%315%35%30%5%
621
11th to 20thDay
7%218%38%30%5%
618
21st to endDay
6%312%32%40%8%
579
August1st to 10thDay
10%214%25%38%11%
447
11th to 20thDay
8%310%36%35%8%
437
21st to endDay
12%5%17%40%24%3
495
September1st to 10thDay
16%420%36%19%3
450
11th to 20thDay
23%6%18%26%21%6%
450
21st to endDay
23%6%22%27%17%5%
450
October1st to 10thDay
28%5%18%25%18%5%
450
11th to 20thDay
38%6%14%20%17%5%
450
21st to endDay
38%12%17%21%9%4
369
November1st to 10thDay
37%12%23%15%12%
180
11th to 20thDay
42%7%13%19%14%6%
180
21st to endDay
42%12%18%11%9%7%
180
December1st to 10thDay
46%420%14%12%4
180
11th to 20thDay
40%10%21%21%7%1
180
21st to endDay
42%10%27%17%41
198
January1st to 10thNight
48%9%19%14%10%1
850
11th to 20thNight
43%7%16%21%12%
850
21st to endNight
41%6%19%24%9%1
866
February1st to 10thNight
37%7%23%23%11%
760
11th to 20thNight
34%6%23%26%9%1
722
21st to endNight
33%9%22%21%11%4
592
March1st to 10thNight
34%7%21%23%14%2
720
11th to 20thNight
37%9%17%22%13%1
720
21st to endNight
37%6%18%23%14%2
792
April1st to 10thNight
32%8%15%27%14%5%
720
11th to 20thNight
26%7%24%26%15%2
592
21st to endNight
27%6%20%30%16%1
504
May1st to 10thNight
17%319%33%23%6%
360
11th to 20thNight
18%410%28%32%7%
354
21st to endNight
18%315%31%29%5%
389
June1st to 10thNight
24%313%30%25%4
360
11th to 20thNight
19%414%34%23%6%
360
21st to endNight
12%311%32%37%5%
360
July1st to 10thNight
13%19%24%43%10%
350
11th to 20thNight
9%28%30%41%10%
348
21st to endNight
6%16%25%50%12%
394
August1st to 10thNight
9%26%23%42%20%
394
11th to 20thNight
7%15%27%48%11%
534
21st to endNight
12%311%29%38%6%
630
September1st to 10thNight
10%313%35%31%9%
720
11th to 20thNight
21%5%14%20%29%12%
720
21st to endNight
25%5%15%26%25%4
720
October1st to 10thNight
23%417%29%24%3
720
11th to 20thNight
35%415%27%17%3
720
21st to endNight
39%7%19%24%9%2
792
November1st to 10thNight
43%8%19%24%5%
740
11th to 20thNight
39%7%22%21%10%1
760
21st to endNight
43%421%21%9%2
760
December1st to 10thNight
37%7%18%28%10%1
791
11th to 20thNight
49%7%23%16%5%
850
21st to endNight
47%9%24%15%4
935
Page generated at 2024-02-12 03:35:33. Version ac07

Copyright 2024 Attilla Danko


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