Harold A Campbell Public Use Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Harold A Campbell Public Use Area clear sky chart from 2005-11-05 to 2017-09-23.

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
66%
16228
20%
47007
17%
16190
69%
16190
32%
29117

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
56%
716
20%
2327
17%
716
63%
716
29%
1400
January16th to endNight
54%
768
26%
2460
22%
768
62%
768
34%
1386
February1st to 15thNight
54%
702
26%
2106
22%
700
61%
700
36%
1225
February16th to endNight
60%
631
32%
1743
22%
631
69%
631
45%
965
March1st to 15thNight
61%
720
29%
1980
22%
720
67%
720
45%
1083
March16th to endNight
63%
768
29%
2112
24%
768
67%
768
43%
1182
April1st to 15thNight
70%
718
26%
1976
22%
718
73%
718
50%
1032
April16th to endNight
67%
720
28%
1813
19%
720
70%
720
45%
1056
May1st to 15thNight
75%
719
26%
1799
18%
719
76%
719
51%
1003
May16th to endNight
76%
577
20%
1699
18%
577
76%
577
35%
1057
June1st to 15thNight
67%
540
9%
1620
8%
540
67%
540
20%
1175
June16th to endNight
77%
540
10%
1620
8%
540
77%
540
23%
1140
July1st to 15thNight
75%
510
5%
1530
5%
510
75%
510
22%
1085
July16th to endNight
80%
564
8%
1595
7%
531
81%
531
27%
1077
August1st to 15thNight
76%
590
6%
1660
7%
587
76%
587
28%
1108
August16th to endNight
66%
764
6%
2039
6%
764
66%
764
21%
1483
September1st to 15thNight
68%
720
5%
1980
4%
720
68%
720
20%
1438
September16th to endNight
63%
689
7%
1903
7%
689
63%
689
17%
1433
October1st to 15thNight
71%
660
21%
1911
22%
660
73%
660
30%
1207
October16th to endNight
59%
704
22%
2112
21%
704
61%
704
27%
1347
November1st to 15thNight
67%
700
30%
2101
29%
700
73%
700
38%
1190
November16th to endNight
61%
720
27%
2160
24%
720
67%
720
31%
1324
December1st to 15thNight
64%
720
26%
2265
25%
720
68%
720
31%
1349
December16th to endNight
67%
768
25%
2496
26%
768
71%
768
36%
1372

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
8%6%37%8%5%7%6%6%8%29%
47882
Night
6%425%5%35%5%7%10%43%
47212
TransparencyDay
49%6%13%15%11%3
47583
Night
34%7%18%22%14%3
47015
SeeingDay
8%211%20%26%30%
6048
Night
7%112%32%32%12%
16237

By Month

Percentage Cloud Cover SE (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
8%6%37%7%47%5%6%8%35%
1611
16th to endDay
8%6%35%5%35%5%6%9%39%
1761
February1st to 15thDay
10%6%25%5%25%45%8%41%
1750
16th to endDay
6%426%6%36%5%47%45%
1730
March1st to 15thDay
4425%7%46%6%7%9%39%
1980
16th to endDay
6%425%7%46%7%7%8%39%
2111
April1st to 15thDay
7%325%6%5%6%6%7%9%38%
1972
16th to endDay
7%437%7%36%6%5%9%38%
2145
May1st to 15thDay
4425%7%47%6%6%8%42%
2152
16th to endDay
9%6%48%9%5%8%7%7%8%24%
2423
June1st to 15thDay
13%8%410%10%6%7%7%6%7%15%
2340
16th to endDay
10%7%49%10%6%10%7%7%8%18%
2340
July1st to 15thDay
10%8%49%10%7%9%7%7%7%16%
2340
16th to endDay
8%8%410%11%5%9%7%6%8%18%
2465
August1st to 15thDay
8%7%410%9%6%9%6%8%9%19%
2274
16th to endDay
11%7%49%10%6%8%8%8%8%18%
2158
September1st to 15thDay
9%8%5%9%11%7%9%7%7%8%16%
1980
16th to endDay
12%10%410%10%5%8%7%6%7%15%
1894
October1st to 15thDay
7%6%28%9%6%7%7%7%9%26%
1719
16th to endDay
13%6%36%7%46%7%6%8%29%
1760
November1st to 15thDay
6%425%6%5%7%6%5%8%39%
1757
16th to endDay
10%6%27%5%36%6%5%6%38%
1800
December1st to 15thDay
8%7%47%6%46%5%5%7%35%
1692
16th to endDay
6%5%35%6%36%6%6%10%40%
1728
January1st to 15thNight
8%6%245%35%5%5%9%42%
2327
16th to endNight
5%425%5%345%6%9%47%
2460
February1st to 15thNight
10%42332446%8%47%
2103
16th to endNight
4213425%6%5%8%54%
1743
March1st to 15thNight
3313425%46%8%55%
1980
16th to endNight
4323425%45%9%53%
2112
April1st to 15thNight
32133245%5%11%56%
1976
16th to endNight
6%3134245%5%9%53%
1813
May1st to 15thNight
3223325%5%5%11%56%
1799
16th to endNight
6%3245%35%7%8%14%38%
1698
June1st to 15thNight
10%6%36%7%5%6%7%9%10%25%
1620
16th to endNight
5%426%6%5%7%7%9%12%32%
1620
July1st to 15thNight
6%5%35%6%5%7%6%9%11%32%
1620
16th to endNight
4426%6%47%7%9%12%35%
1703
August1st to 15thNight
5%426%5%36%7%8%12%37%
1671
16th to endNight
8%5%26%7%5%7%6%9%10%29%
2039
September1st to 15thNight
7%336%7%48%7%10%13%26%
1980
16th to endNight
8%6%37%8%5%7%7%9%10%24%
1903
October1st to 15thNight
6%425%5%35%6%8%9%41%
1911
16th to endNight
11%426%6%35%45%9%40%
2112
November1st to 15thNight
6%2245%345%5%9%50%
2101
16th to endNight
10%5%345%35%45%7%45%
2160
December1st to 15thNight
6%4245%45%5%6%9%44%
2265
16th to endNight
6%4244345%7%9%49%
2496

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
45%5%10%17%15%4
1612
16th to endDay
40%39%21%19%5%
1761
February1st to 15thDay
39%36%23%18%8%
1752
16th to endDay
37%39%24%17%7%
1730
March1st to 15thDay
38%210%25%19%3
1980
16th to endDay
40%49%21%18%6%
2112
April1st to 15thDay
39%412%21%18%3
1972
16th to endDay
41%5%8%21%19%4
2145
May1st to 15thDay
37%411%23%16%6%
2152
16th to endDay
54%5%12%18%8%
2427
June1st to 15thDay
64%6%14%10%4
2340
16th to endDay
60%8%19%9%2
2340
July1st to 15thDay
63%10%19%5%
2201
16th to endDay
59%9%21%9%
2310
August1st to 15thDay
58%8%21%11%
2261
16th to endDay
60%10%20%8%
2158
September1st to 15thDay
62%10%17%8%
1980
16th to endDay
66%7%13%9%2
1894
October1st to 15thDay
51%7%11%14%12%2
1719
16th to endDay
51%47%14%16%5%
1760
November1st to 15thDay
40%48%18%21%7%
1757
16th to endDay
43%5%7%14%20%8%
1800
December1st to 15thDay
46%5%9%16%17%4
1692
16th to endDay
38%411%22%17%5%
1728
January1st to 15thNight
37%5%14%24%15%3
2327
16th to endNight
32%412%27%17%5%
2460
February1st to 15thNight
32%38%26%19%8%
2112
16th to endNight
26%313%27%22%6%
1743
March1st to 15thNight
25%312%31%20%6%
1980
16th to endNight
26%5%14%29%19%5%
2112
April1st to 15thNight
20%419%32%18%4
1976
16th to endNight
27%412%27%23%4
1813
May1st to 15thNight
22%415%34%17%5%
1800
16th to endNight
33%6%19%30%9%
1700
June1st to 15thNight
47%10%22%16%3
1620
16th to endNight
40%13%28%15%2
1620
July1st to 15thNight
41%13%33%10%
1530
16th to endNight
35%13%35%14%1
1595
August1st to 15thNight
36%10%35%16%
1660
16th to endNight
43%13%29%12%
2039
September1st to 15thNight
43%14%29%10%1
1980
16th to endNight
49%11%21%13%3
1903
October1st to 15thNight
36%7%18%19%16%2
1911
16th to endNight
41%49%20%17%5%
2112
November1st to 15thNight
30%49%24%24%6%
2101
16th to endNight
38%38%18%21%8%
2160
December1st to 15thNight
34%5%12%23%19%3
2265
16th to endNight
29%413%26%20%3
2496

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
18%8%27%27%13%3
90
16th to endDay
15%15%26%28%8%6%
96
February1st to 15thDay
4431%32%15%12%
90
16th to endDay
8%226%35%24%2
231
March1st to 15thDay
6%421%35%28%3
270
16th to endDay
5%319%32%30%8%
288
April1st to 15thDay
6%318%27%30%13%
270
16th to endDay
9%15%25%34%15%
270
May1st to 15thDay
213%23%35%24%
288
16th to endDay
5%26%19%33%32%
331
June1st to 15thDay
13%36%14%24%37%
315
16th to endDay
5%139%24%55%
315
July1st to 15thDay
4116%22%63%
305
16th to endDay
7%117%22%59%
326
August1st to 15thDay
7%17%21%61%
313
16th to endDay
12%139%21%50%
332
September1st to 15thDay
7%138%23%55%
315
16th to endDay
12%139%24%49%
283
October1st to 15thDay
7%6%22%41%20%
255
16th to endDay
13%218%24%26%14%
272
November1st to 15thDay
9%8%35%31%15%
265
16th to endDay
5%122%35%28%5%
270
December1st to 15thDay
15%417%30%27%4
162
16th to endDay
4214%42%30%6%
96
January1st to 15thNight
10%5%18%35%27%1
720
16th to endNight
6%426%42%18%1
768
February1st to 15thNight
12%123%43%17%
704
16th to endNight
5%227%47%17%
631
March1st to 15thNight
5%224%45%19%1
720
16th to endNight
6%220%46%21%1
768
April1st to 15thNight
4216%49%26%1
718
16th to endNight
7%116%49%23%1
720
May1st to 15thNight
312%46%32%3
720
16th to endNight
6%2335%41%11%
579
June1st to 15thNight
11%1318%44%20%
540
16th to endNight
417%48%37%
540
July1st to 15thNight
8%17%43%39%
510
16th to endNight
45%42%46%
564
August1st to 15thNight
6%16%45%39%
590
16th to endNight
9%1213%37%34%
764
September1st to 15thNight
8%1311%42%33%
720
16th to endNight
11%1314%42%27%
689
October1st to 15thNight
8%15%32%41%10%
660
16th to endNight
14%112%32%30%8%
704
November1st to 15thNight
6%114%40%32%5%
700
16th to endNight
11%115%40%27%2
720
December1st to 15thNight
9%113%42%30%2
720
16th to endNight
6%215%39%32%4
768
Page generated at 2017-09-24 09:15:47. Version ac04

Copyright 2017 A. Danko


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