Tanaeum Ridge and Peoh Point
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Tanaeum Ridge and Peoh Point clear sky chart from 2005-11-05 to 2018-02-14.

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
36%
15120
14%
48845
9%
15093
43%
15093
19%
31929

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
29%
777
8%
2716
6%
776
32%
776
8%
2106
January16th to endNight
35%
832
10%
2912
9%
832
39%
832
12%
2126
February1st to 15thNight
30%
754
10%
2470
6%
753
37%
753
13%
1809
February16th to endNight
36%
632
13%
1972
9%
632
42%
632
16%
1388
March1st to 15thNight
31%
720
10%
2113
5%
720
37%
720
14%
1552
March16th to endNight
29%
768
10%
2032
3%
768
33%
768
15%
1499
April1st to 15thNight
30%
719
12%
1799
4%
719
34%
719
18%
1311
April16th to endNight
30%
580
13%
1660
5%
580
37%
580
19%
1131
May1st to 15thNight
37%
359
18%
1439
16%
359
49%
359
21%
828
May16th to endNight
37%
375
9%
1496
10%
374
45%
374
17%
932
June1st to 15thNight
30%
360
9%
1440
4%
360
38%
360
19%
840
June16th to endNight
30%
360
10%
1440
7%
360
40%
360
23%
756
July1st to 15thNight
42%
340
16%
1360
11%
340
57%
340
46%
537
July16th to endNight
41%
376
25%
1416
20%
354
65%
354
52%
515
August1st to 15thNight
53%
407
29%
1479
19%
405
70%
405
56%
580
August16th to endNight
49%
685
31%
1831
15%
685
59%
685
52%
921
September1st to 15thNight
55%
720
28%
1800
12%
720
62%
720
55%
924
September16th to endNight
48%
716
25%
1953
16%
716
55%
716
36%
1119
October1st to 15thNight
44%
720
18%
2160
14%
720
50%
720
27%
1319
October16th to endNight
42%
768
16%
2408
12%
768
49%
768
19%
1624
November1st to 15thNight
31%
760
10%
2577
6%
760
37%
760
11%
1868
November16th to endNight
30%
780
10%
2730
5%
780
38%
780
11%
2001
December1st to 15thNight
32%
780
11%
2730
8%
780
36%
780
12%
2016
December16th to endNight
20%
832
9%
2912
3%
832
26%
832
8%
2227

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
7%7%36%6%35%5%6%7%39%
49253
Night
7%7%36%6%35%5%6%8%38%
49013
Cloud CoverDay
6%6%35%5%35%5%6%8%42%
49253
Night
6%7%35%5%35%5%6%8%41%
49017
TransparencyDay
37%11%14%21%12%2
48924
Night
37%11%16%21%10%2
48846
SeeingDay
12%23%33%21%6%1
5872
Night
10%17%29%27%12%2
15130

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
10%12%5%9%6%45%7%7%9%22%
1552
16th to endDay
9%13%47%7%35%6%6%9%26%
1664
February1st to 15thDay
10%10%48%7%46%5%7%8%24%
1694
16th to endDay
8%11%48%7%5%7%6%6%7%26%
1502
March1st to 15thDay
10%12%49%8%47%5%6%7%21%
1845
16th to endDay
8%11%5%10%10%6%6%7%7%7%17%
2191
April1st to 15thDay
8%12%410%9%48%5%5%7%22%
2149
16th to endDay
5%9%48%7%46%6%7%8%30%
2297
May1st to 15thDay
7%6%37%6%47%5%7%9%36%
2511
16th to endDay
11%8%36%7%45%6%6%8%31%
2615
June1st to 15thDay
8%5%36%6%45%5%7%8%38%
2520
16th to endDay
6%4246%46%5%6%7%44%
2520
July1st to 15thDay
21332445%6%64%
2520
16th to endDay
3112213345%70%
2657
August1st to 15thDay
111222335%7%66%
2472
16th to endDay
2214424347%61%
2370
September1st to 15thDay
3212323447%63%
2160
16th to endDay
6%426%6%35%5%5%7%45%
2004
October1st to 15thDay
9%7%16%6%245%5%8%40%
1800
16th to endDay
12%8%36%5%45%5%6%7%33%
1815
November1st to 15thDay
9%10%5%11%8%46%5%7%8%22%
1611
16th to endDay
10%15%5%8%7%45%45%7%25%
1560
December1st to 15thDay
8%11%5%9%7%45%5%6%8%26%
1560
16th to endDay
12%13%5%10%7%35%5%6%7%22%
1664
January1st to 15thNight
11%10%49%7%46%6%6%10%23%
2716
16th to endNight
10%9%38%7%46%6%7%9%27%
2912
February1st to 15thNight
10%12%5%6%5%35%5%6%10%29%
2458
16th to endNight
8%9%46%6%45%6%6%8%32%
1972
March1st to 15thNight
9%8%47%7%47%6%6%8%29%
2113
16th to endNight
7%8%47%8%46%7%10%9%25%
2028
April1st to 15thNight
6%6%37%7%48%8%7%9%30%
1799
16th to endNight
5%6%36%8%36%7%9%9%32%
1660
May1st to 15thNight
6%425%6%25%7%7%8%41%
1439
16th to endNight
7%5%26%5%48%6%7%9%34%
1496
June1st to 15thNight
5%417%6%35%5%7%8%42%
1440
16th to endNight
4425%5%26%5%7%7%48%
1440
July1st to 15thNight
11122335%7%69%
1440
16th to endNight
11212336%75%
1512
August1st to 15thNight
11213348%72%
1487
16th to endNight
111331345%7%66%
1831
September1st to 15thNight
2212212346%69%
1800
16th to endNight
3325%5%235%6%9%50%
1953
October1st to 15thNight
8%5%26%6%345%6%7%45%
2160
16th to endNight
10%7%26%5%36%5%6%9%35%
2408
November1st to 15thNight
12%10%37%5%46%6%6%8%27%
2577
16th to endNight
8%11%48%7%46%6%6%8%26%
2730
December1st to 15thNight
9%10%5%8%7%46%46%8%27%
2730
16th to endNight
11%15%6%10%7%3445%8%22%
2912

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
11%11%5%8%9%36%6%7%9%21%
1552
16th to endDay
9%11%5%6%6%35%7%7%9%27%
1664
February1st to 15thDay
9%11%37%6%26%7%7%8%27%
1694
16th to endDay
7%10%47%7%36%7%6%8%30%
1502
March1st to 15thDay
9%11%48%7%5%7%6%6%8%24%
1845
16th to endDay
7%9%5%9%8%5%7%7%6%9%23%
2191
April1st to 15thDay
7%9%47%7%47%6%8%7%28%
2149
16th to endDay
5%6%36%5%46%7%7%9%37%
2297
May1st to 15thDay
6%5%25%5%36%5%7%10%41%
2511
16th to endDay
9%5%26%6%35%6%7%8%36%
2615
June1st to 15thDay
7%325%5%45%6%6%7%45%
2520
16th to endDay
5%315%5%35%46%8%49%
2520
July1st to 15thDay
112324336%68%
2520
16th to endDay
2112212335%72%
2657
August1st to 15thDay
11221335%6%69%
2472
16th to endDay
1213433447%64%
2370
September1st to 15thDay
2212322446%67%
2160
16th to endDay
6%3245%35%5%6%6%49%
2004
October1st to 15thDay
8%5%25%6%3446%9%43%
1800
16th to endDay
10%7%35%5%45%6%6%8%36%
1815
November1st to 15thDay
8%9%39%8%46%6%6%7%26%
1611
16th to endDay
10%12%5%8%6%36%5%6%8%26%
1560
December1st to 15thDay
8%11%5%9%6%36%6%8%7%26%
1560
16th to endDay
12%12%5%9%6%35%5%6%7%25%
1664
January1st to 15thNight
10%10%5%9%8%46%6%6%10%22%
2716
16th to endNight
10%10%37%6%46%7%7%10%24%
2912
February1st to 15thNight
9%11%5%7%5%345%6%10%31%
2458
16th to endNight
7%8%45%5%35%6%7%7%37%
1972
March1st to 15thNight
8%8%36%7%36%6%7%8%32%
2113
16th to endNight
6%7%35%6%47%6%9%10%32%
2032
April1st to 15thNight
6%5%26%6%46%6%7%9%38%
1799
16th to endNight
45%35%6%35%6%7%10%41%
1660
May1st to 15thNight
5%325%5%35%5%6%8%48%
1439
16th to endNight
5%5%25%6%46%7%8%8%40%
1496
June1st to 15thNight
5%22445%6%5%7%7%47%
1440
16th to endNight
2415%4345%6%7%53%
1440
July1st to 15thNight
111122347%72%
1440
16th to endNight
1112236%78%
1512
August1st to 15thNight
111235%6%75%
1487
16th to endNight
11231235%7%68%
1831
September1st to 15thNight
212212237%72%
1800
16th to endNight
3215%32446%9%54%
1953
October1st to 15thNight
7%4145%345%6%6%49%
2160
16th to endNight
8%6%26%5%35%6%7%9%38%
2408
November1st to 15thNight
11%9%26%6%35%6%7%8%31%
2577
16th to endNight
8%10%5%7%7%35%6%7%8%30%
2730
December1st to 15thNight
9%9%47%7%46%6%6%7%29%
2730
16th to endNight
11%15%5%8%6%245%5%7%25%
2912

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
57%14%11%12%31
1552
16th to endDay
50%11%15%14%7%
1664
February1st to 15thDay
51%14%16%13%3
1694
16th to endDay
47%15%15%16%5%
1502
March1st to 15thDay
55%11%14%12%5%
1845
16th to endDay
54%16%14%12%2
2191
April1st to 15thDay
50%13%15%15%4
2149
16th to endDay
39%17%17%19%5%
2297
May1st to 15thDay
35%11%17%24%10%1
2511
16th to endDay
40%14%19%20%5%
2619
June1st to 15thDay
33%12%16%24%10%2
2520
16th to endDay
28%11%16%27%14%1
2520
July1st to 15thDay
17%6%10%26%28%10%
2371
16th to endDay
14%48%26%30%14%
2490
August1st to 15thDay
14%6%10%34%25%8%
2455
16th to endDay
18%7%12%30%26%5%
2370
September1st to 15thDay
18%5%12%28%28%7%
2160
16th to endDay
30%10%17%21%15%5%
2004
October1st to 15thDay
36%10%15%26%10%
1800
16th to endDay
42%10%15%21%10%
1815
November1st to 15thDay
52%14%12%15%31
1611
16th to endDay
53%12%13%14%4
1560
December1st to 15thDay
53%11%13%16%6%
1560
16th to endDay
54%13%12%13%5%
1664
January1st to 15thNight
55%12%14%12%4
2716
16th to endNight
50%11%15%14%5%1
2912
February1st to 15thNight
46%13%17%15%4
2470
16th to endNight
42%13%17%20%5%
1972
March1st to 15thNight
46%12%17%17%5%
2113
16th to endNight
41%16%19%19%2
2032
April1st to 15thNight
39%16%17%21%6%
1799
16th to endNight
32%18%20%21%6%
1660
May1st to 15thNight
30%12%15%30%9%1
1440
16th to endNight
35%14%22%22%5%
1496
June1st to 15thNight
30%13%18%26%9%
1440
16th to endNight
25%11%18%29%12%2
1440
July1st to 15thNight
11%7%15%32%23%9%
1360
16th to endNight
7%6%10%30%28%15%
1416
August1st to 15thNight
8%7%13%33%27%9%
1479
16th to endNight
13%7%14%33%24%5%
1831
September1st to 15thNight
12%6%14%27%32%6%
1800
16th to endNight
24%8%20%26%14%6%
1953
October1st to 15thNight
31%9%14%28%14%1
2160
16th to endNight
39%12%13%21%12%
2408
November1st to 15thNight
47%13%16%17%41
2577
16th to endNight
49%12%14%15%7%
2730
December1st to 15thNight
50%12%13%18%4
2730
16th to endNight
55%11%15%11%5%
2912

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
21%12%15%30%16%4
90
16th to endDay
22%18%29%17%8%3
96
February1st to 15thDay
17%27%32%17%31
276
16th to endDay
19%27%32%15%4
225
March1st to 15thDay
20%38%28%12%1
270
16th to endDay
21%36%29%8%3
288
April1st to 15thDay
15%35%28%14%5%
269
16th to endDay
15%37%30%10%32
270
May1st to 15thDay
19%24%31%19%31
288
16th to endDay
11%19%31%25%9%2
330
June1st to 15thDay
9%24%41%19%5%
315
16th to endDay
8%28%37%18%6%
315
July1st to 15thDay
115%47%29%4
305
16th to endDay
320%41%24%7%
327
August1st to 15thDay
5%11%39%29%10%4
315
16th to endDay
412%38%28%12%3
332
September1st to 15thDay
6%23%31%26%10%2
315
16th to endDay
8%18%37%26%7%
315
October1st to 15thDay
15%24%31%20%7%
315
16th to endDay
17%19%25%25%7%3
231
November1st to 15thDay
19%25%32%20%2
109
16th to endDay
18%22%24%20%10%4
90
December1st to 15thDay
10%23%30%15%10%11%
90
16th to endDay
15%17%29%26%10%1
96
January1st to 15thNight
16%18%21%26%14%1
780
16th to endNight
15%15%25%27%13%3
832
February1st to 15thNight
13%17%27%28%11%1
760
16th to endNight
13%20%21%28%14%1
632
March1st to 15thNight
13%18%29%28%9%1
720
16th to endNight
10%23%29%25%9%1
768
April1st to 15thNight
9%22%31%25%9%1
719
16th to endNight
7%24%33%21%10%2
580
May1st to 15thNight
7%22%30%25%11%1
360
16th to endNight
7%14%34%29%12%1
375
June1st to 15thNight
7%18%40%23%8%
360
16th to endNight
5%24%36%22%8%1
360
July1st to 15thNight
212%41%34%9%
340
16th to endNight
114%41%32%9%1
376
August1st to 15thNight
18%35%35%15%3
407
16th to endNight
312%32%30%17%4
685
September1st to 15thNight
312%25%27%23%6%
720
16th to endNight
5%16%26%27%19%5%
716
October1st to 15thNight
10%15%25%27%17%3
720
16th to endNight
12%15%23%28%15%3
768
November1st to 15thNight
16%17%26%29%9%
760
16th to endNight
14%18%27%21%14%3
780
December1st to 15thNight
12%16%29%23%15%2
780
16th to endNight
18%21%27%27%4
832
Page generated at 2018-02-15 07:58:52. Version ac04

Copyright 2018 A. Danko


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