Roseburg Airport
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Roseburg Airport clear sky chart from 2005-11-06 to 2024-03-18.

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
51%
23105
14%
80759
15%
23008
53%
23008
19%
55616

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
31%
751
5%
4397
8%
736
33%
736
5%
3658
January11th to 20thNight
39%
756
8%
4272
12%
740
40%
740
7%
3435
January21st to endNight
44%
834
10%
4480
17%
814
45%
814
8%
3616
February1st to 10thNight
41%
760
9%
2470
10%
760
42%
760
13%
1905
February11th to 20thNight
38%
741
10%
2404
11%
740
40%
740
14%
1834
February21st to endNight
39%
628
10%
1960
10%
628
41%
628
13%
1514
March1st to 10thNight
37%
760
9%
2123
8%
760
39%
760
15%
1653
March11th to 20thNight
44%
752
11%
2067
9%
752
46%
752
18%
1579
March21st to endNight
34%
792
5%
2170
3%
792
35%
792
12%
1794
April1st to 10thNight
35%
720
9%
1800
6%
720
36%
720
15%
1455
April11th to 20thNight
41%
711
10%
1779
6%
711
42%
711
19%
1384
April21st to endNight
47%
563
10%
1643
7%
563
48%
563
18%
1197
May1st to 10thNight
51%
505
13%
1585
10%
505
54%
505
23%
1044
May11th to 20thNight
56%
354
13%
1416
17%
354
58%
354
18%
926
May21st to endNight
52%
389
10%
1552
12%
388
55%
388
18%
1010
June1st to 10thNight
58%
360
11%
1440
17%
360
59%
360
20%
895
June11th to 20thNight
59%
360
14%
1440
19%
360
64%
360
27%
789
June21st to endNight
76%
360
22%
1440
34%
360
79%
360
45%
610
July1st to 10thNight
84%
350
23%
1400
36%
350
87%
350
52%
543
July11th to 20thNight
79%
348
31%
1392
42%
348
86%
348
55%
521
July21st to endNight
88%
511
37%
1599
41%
483
92%
483
75%
584
August1st to 10thNight
86%
537
30%
1602
28%
534
87%
534
60%
708
August11th to 20thNight
85%
534
36%
1602
29%
534
87%
534
62%
700
August21st to endNight
76%
728
37%
1916
25%
728
79%
728
64%
929
September1st to 10thNight
74%
720
35%
1800
23%
720
75%
720
64%
909
September11th to 20thNight
72%
720
30%
1836
21%
720
74%
720
47%
1057
September21st to endNight
65%
720
27%
2042
24%
720
67%
720
38%
1176
October1st to 10thNight
61%
720
17%
2160
17%
720
64%
720
34%
1285
October11th to 20thNight
61%
720
20%
2160
23%
720
62%
720
30%
1342
October21st to endNight
48%
792
18%
2376
18%
792
50%
792
21%
1663
November1st to 10thNight
45%
740
12%
2420
13%
740
46%
740
16%
1779
November11th to 20thNight
38%
760
10%
2660
10%
760
39%
760
11%
2059
November21st to endNight
47%
760
11%
2660
12%
760
49%
760
16%
1896
December1st to 10thNight
45%
760
12%
2660
13%
760
45%
760
15%
1925
December11th to 20thNight
37%
759
9%
3199
10%
759
38%
759
9%
2507
December21st to endNight
27%
830
4%
4837
8%
817
28%
817
5%
3735

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
17%9%36%5%3445%6%37%
78694
Night
19%9%36%5%3445%6%36%
81116
TransparencyDay
47%6%12%19%13%3
78404
Night
49%6%12%18%11%3
80927
SeeingDay
18%12%24%26%15%5%
13961
Night
20%7%14%31%25%3
23130

By Month

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 10thDay
27%15%6%9%7%35%45%5%14%
2539
11th to 20thDay
36%13%48%6%4444414%
2672
21st to endDay
25%13%47%6%345%6%7%19%
3146
February1st to 10thDay
23%10%47%6%36%7%7%7%19%
1710
11th to 20thDay
23%12%5%8%7%35%5%5%6%21%
1665
21st to endDay
25%14%6%8%7%3445%6%19%
1492
March1st to 10thDay
22%12%6%8%7%45%5%5%6%20%
2052
11th to 20thDay
24%10%46%5%45%5%5%6%26%
2059
21st to endDay
25%12%48%7%36%5%5%6%18%
2186
April1st to 10thDay
23%13%5%9%7%46%45%5%19%
2160
11th to 20thDay
21%12%5%10%5%35%45%5%25%
2129
21st to endDay
21%8%47%5%345%5%8%30%
2312
May1st to 10thDay
16%7%36%5%35%5%6%7%37%
2372
11th to 20thDay
18%9%36%6%435%6%7%33%
2477
21st to endDay
23%9%36%5%45%45%7%31%
2723
June1st to 10thDay
19%9%36%5%35%347%36%
2520
11th to 20thDay
15%6%36%5%35%46%7%40%
2520
21st to endDay
8%42432435%6%60%
2520
July1st to 10thDay
5%313312335%70%
2520
11th to 20thDay
6%42231323470%
2520
21st to endDay
341221223474%
2621
August1st to 10thDay
3413323346%69%
2328
11th to 20thDay
3312222346%73%
2298
21st to endDay
4412313346%69%
2439
September1st to 10thDay
5%313313345%69%
2160
11th to 20thDay
9%6%35%324447%54%
2120
21st to endDay
11%42443446%7%51%
1918
October1st to 10thDay
14%7%36%5%4345%6%44%
1800
11th to 20thDay
15%7%36%6%345%6%7%38%
1800
21st to endDay
19%10%47%5%245%6%7%31%
1980
November1st to 10thDay
25%9%38%7%5%46%6%7%21%
1654
11th to 20thDay
25%10%48%7%45%6%6%6%19%
1520
21st to endDay
25%9%47%5%445%5%8%25%
1520
December1st to 10thDay
19%9%47%7%35%6%5%7%27%
1520
11th to 20thDay
23%12%37%9%35%5%7%8%17%
1928
21st to endDay
27%15%5%9%7%45%5%6%5%12%
2794
January1st to 10thNight
28%15%5%9%7%45%5%5%413%
4406
11th to 20thNight
32%14%47%6%34445%17%
4288
21st to endNight
30%14%5%8%6%34345%19%
4521
February1st to 10thNight
22%13%47%6%35%5%6%7%22%
2470
11th to 20thNight
23%14%47%5%3335%7%25%
2402
21st to endNight
22%13%47%6%35%46%6%25%
1960
March1st to 10thNight
24%13%5%6%435%45%7%23%
2123
11th to 20thNight
19%11%48%6%3445%6%29%
2067
21st to endNight
26%13%47%7%35%446%20%
2170
April1st to 10thNight
25%11%47%6%445%5%6%24%
1800
11th to 20thNight
20%11%46%6%34446%31%
1779
21st to endNight
19%8%45%5%45%5%5%7%31%
1643
May1st to 10thNight
17%9%345%235%47%41%
1585
11th to 20thNight
15%7%37%6%35%5%47%37%
1416
21st to endNight
18%7%36%5%25%35%7%39%
1552
June1st to 10thNight
16%6%25%5%3446%7%42%
1440
11th to 20thNight
11%5%35%434346%53%
1440
21st to endNight
8%212212235%70%
1440
July1st to 10thNight
4212212345%75%
1440
11th to 20thNight
321322223476%
1440
21st to endNight
211111112484%
1693
August1st to 10thNight
3212313335%74%
1611
11th to 20thNight
32221234476%
1602
21st to endNight
3212212235%77%
1916
September1st to 10thNight
5%212212235%75%
1800
11th to 20thNight
7%424333447%60%
1836
21st to endNight
12%5%2432335%7%54%
2042
October1st to 10thNight
11%6%35%5%3335%6%51%
2160
11th to 20thNight
13%6%36%43345%7%45%
2160
21st to endNight
20%9%36%5%44446%37%
2376
November1st to 10thNight
24%8%37%6%35%46%8%26%
2420
11th to 20thNight
27%10%38%6%45%45%7%21%
2660
21st to endNight
22%8%46%5%3446%8%29%
2660
December1st to 10thNight
22%10%48%5%3446%6%28%
2660
11th to 20thNight
25%13%48%6%35%5%5%7%19%
3276
21st to endNight
24%12%49%8%45%5%7%6%15%
4862

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
71%6%11%8%21
2539
11th to 20thDay
71%7%6%8%44
2672
21st to endDay
62%8%12%11%6%2
3146
February1st to 10thDay
60%8%14%12%5%1
1710
11th to 20thDay
62%8%12%13%42
1674
21st to endDay
66%7%9%11%6%1
1492
March1st to 10thDay
64%7%12%13%4
2052
11th to 20thDay
58%6%12%18%5%1
2059
21st to endDay
65%8%12%12%3
2186
April1st to 10thDay
66%6%11%12%4
2160
11th to 20thDay
61%7%13%11%6%2
2132
21st to endDay
53%7%16%15%8%1
2312
May1st to 10thDay
45%6%19%21%8%1
2372
11th to 20thDay
49%7%16%20%6%1
2480
21st to endDay
54%6%18%18%4
2724
June1st to 10thDay
50%5%17%23%5%
2520
11th to 20thDay
43%7%16%26%8%
2520
21st to endDay
25%5%16%34%17%3
2520
July1st to 10thDay
19%314%29%25%9%
2451
11th to 20thDay
19%48%23%35%11%
2445
21st to endDay
15%26%25%43%9%
2475
August1st to 10thDay
19%412%36%23%6%
2312
11th to 20thDay
14%311%32%32%8%
2298
21st to endDay
19%310%32%31%6%
2439
September1st to 10thDay
19%38%27%29%14%
2160
11th to 20thDay
30%413%27%18%7%
2120
21st to endDay
32%414%24%18%7%
1918
October1st to 10thDay
40%6%10%20%17%8%
1800
11th to 20thDay
42%7%15%18%14%4
1800
21st to endDay
51%6%11%16%13%4
1980
November1st to 10thDay
60%6%11%15%7%1
1654
11th to 20thDay
62%7%10%10%7%3
1520
21st to endDay
57%6%11%10%13%4
1520
December1st to 10thDay
54%8%10%15%12%1
1520
11th to 20thDay
60%8%15%12%4
1928
21st to endDay
69%7%11%9%31
2794
January1st to 10thNight
72%7%9%8%31
4406
11th to 20thNight
66%7%8%11%44
4288
21st to endNight
69%48%12%6%2
4521
February1st to 10thNight
60%6%13%13%6%1
2470
11th to 20thNight
59%6%12%16%5%2
2404
21st to endNight
60%7%13%13%5%2
1960
March1st to 10thNight
60%5%13%17%31
2123
11th to 20thNight
56%6%13%18%5%1
2067
21st to endNight
65%7%15%11%2
2170
April1st to 10thNight
62%6%14%13%4
1800
11th to 20thNight
56%7%16%14%43
1779
21st to endNight
52%7%19%16%5%2
1643
May1st to 10thNight
43%7%18%22%9%1
1585
11th to 20thNight
47%7%18%21%6%1
1416
21st to endNight
46%7%22%21%4
1552
June1st to 10thNight
41%8%17%30%4
1440
11th to 20thNight
35%5%21%32%6%1
1440
21st to endNight
19%419%38%18%2
1440
July1st to 10thNight
15%314%30%28%10%
1400
11th to 20thNight
14%38%28%35%12%
1392
21st to endNight
8%15%32%44%10%
1599
August1st to 10thNight
14%314%39%25%5%
1602
11th to 20thNight
13%311%34%33%7%
1602
21st to endNight
12%411%34%30%8%
1916
September1st to 10thNight
15%38%31%29%13%
1800
11th to 20thNight
25%5%14%31%18%7%
1836
21st to endNight
30%5%13%25%19%8%
2042
October1st to 10thNight
34%5%13%22%19%7%
2160
11th to 20thNight
38%5%17%21%17%3
2160
21st to endNight
48%6%11%16%14%4
2376
November1st to 10thNight
55%7%15%13%10%1
2420
11th to 20thNight
62%7%10%11%8%3
2660
21st to endNight
53%6%10%14%12%5%
2660
December1st to 10thNight
54%6%11%17%10%1
2660
11th to 20thNight
63%7%12%13%6%
3276
21st to endNight
64%9%13%10%31
4862

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
33%17%22%16%9%2
180
11th to 20thDay
33%14%15%21%10%8%
260
21st to endDay
25%14%23%16%18%4
407
February1st to 10thDay
25%12%21%24%16%2
370
11th to 20thDay
31%16%22%20%9%2
365
21st to endDay
31%18%20%23%8%1
346
March1st to 10thDay
30%17%23%22%8%1
460
11th to 20thDay
26%14%24%21%14%2
449
21st to endDay
28%17%25%21%8%2
462
April1st to 10thDay
25%20%24%20%10%1
420
11th to 20thDay
28%18%24%19%8%3
412
21st to endDay
24%19%24%21%9%3
420
May1st to 10thDay
19%15%28%23%11%4
423
11th to 20thDay
26%16%23%21%10%4
448
21st to endDay
23%13%23%24%12%5%
485
June1st to 10thDay
16%16%24%24%14%6%
450
11th to 20thDay
13%21%30%23%11%2
450
21st to endDay
5%8%32%35%16%4
450
July1st to 10thDay
5%7%30%37%17%5%
446
11th to 20thDay
37%30%39%14%7%
444
21st to endDay
2329%38%21%6%
487
August1st to 10thDay
4326%40%19%9%
447
11th to 20thDay
36%20%37%24%10%
437
21st to endDay
5%7%28%31%22%7%
495
September1st to 10thDay
6%7%26%30%22%8%
450
11th to 20thDay
10%10%23%34%18%5%
450
21st to endDay
13%8%27%26%19%7%
450
October1st to 10thDay
16%11%19%27%22%6%
450
11th to 20thDay
17%10%18%26%23%7%
450
21st to endDay
23%10%22%22%18%5%
495
November1st to 10thDay
22%15%20%24%15%4
285
11th to 20thDay
22%11%21%26%15%6%
180
21st to endDay
26%12%15%25%21%1
180
December1st to 10thDay
26%10%19%23%14%8%
180
11th to 20thDay
32%15%16%21%12%3
180
21st to endDay
33%13%16%22%14%2
198
January1st to 10thNight
32%11%18%22%14%3
760
11th to 20thNight
27%12%13%26%18%5%
760
21st to endNight
26%6%14%29%21%4
836
February1st to 10thNight
25%9%15%29%21%2
760
11th to 20thNight
28%10%14%29%18%1
744
21st to endNight
26%10%16%32%15%
628
March1st to 10thNight
29%11%16%28%15%1
760
11th to 20thNight
21%11%15%33%19%1
752
21st to endNight
30%11%16%28%15%1
792
April1st to 10thNight
26%12%19%24%17%2
720
11th to 20thNight
22%11%19%28%17%3
711
21st to endNight
21%7%16%31%22%2
563
May1st to 10thNight
20%7%16%30%25%2
505
11th to 20thNight
14%6%12%34%32%2
354
21st to endNight
17%6%17%29%28%3
389
June1st to 10thNight
17%5%13%33%31%1
360
11th to 20thNight
8%6%21%38%23%3
360
21st to endNight
9%110%40%39%1
360
July1st to 10thNight
5%17%41%44%2
350
11th to 20thNight
3113%49%34%
348
21st to endNight
226%42%44%4
511
August1st to 10thNight
315%36%49%6%
537
11th to 20thNight
315%34%50%6%
534
21st to endNight
4314%38%36%5%
728
September1st to 10thNight
5%215%34%41%3
720
11th to 20thNight
8%410%34%36%8%
720
21st to endNight
12%5%12%34%32%5%
720
October1st to 10thNight
11%315%35%29%6%
720
11th to 20thNight
14%5%12%31%32%7%
720
21st to endNight
23%7%14%30%21%6%
792
November1st to 10thNight
23%7%15%31%22%2
740
11th to 20thNight
29%7%15%29%17%2
760
21st to endNight
24%9%13%31%20%3
760
December1st to 10thNight
26%9%12%27%21%5%
760
11th to 20thNight
31%10%14%27%15%3
760
21st to endNight
37%10%14%25%12%1
836
Page generated at 2024-03-15 11:01:40. Version ac07

Copyright © 2024 Attilla Danko.


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