Whiteside Mountain
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Whiteside Mountain clear sky chart from 2005-11-05 to 2017-12-20.

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
46%
15953
21%
48075
14%
15910
53%
15910
24%
30694

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%
720
22%
2327
10%
716
43%
716
19%
1444
January16th to endNight
24%
768
23%
2496
10%
768
41%
768
21%
1538
February1st to 15thNight
29%
703
24%
2141
9%
700
45%
700
25%
1273
February16th to endNight
24%
631
23%
1893
9%
631
37%
631
21%
1194
March1st to 15thNight
29%
720
22%
2029
11%
720
39%
720
22%
1324
March16th to endNight
34%
768
17%
2112
9%
768
40%
768
24%
1373
April1st to 15thNight
38%
688
23%
1946
13%
688
47%
688
29%
1172
April16th to endNight
47%
540
22%
1644
15%
540
55%
540
28%
1006
May1st to 15thNight
46%
540
15%
1620
8%
540
51%
540
23%
1075
May16th to endNight
58%
561
16%
1683
12%
561
60%
561
26%
1095
June1st to 15thNight
62%
540
12%
1620
10%
540
63%
540
25%
1092
June16th to endNight
71%
540
14%
1620
12%
540
72%
540
31%
1024
July1st to 15thNight
65%
510
9%
1530
8%
510
65%
510
22%
1079
July16th to endNight
69%
564
12%
1595
10%
531
70%
531
25%
1093
August1st to 15thNight
61%
539
13%
1609
12%
536
61%
536
20%
1164
August16th to endNight
64%
588
16%
1857
17%
588
65%
588
21%
1271
September1st to 15thNight
58%
720
15%
1980
14%
720
59%
720
23%
1397
September16th to endNight
59%
717
21%
1980
19%
717
61%
717
27%
1327
October1st to 15thNight
53%
720
29%
2037
23%
720
59%
720
31%
1247
October16th to endNight
48%
768
33%
2304
24%
768
61%
768
33%
1320
November1st to 15thNight
53%
760
26%
2423
23%
760
60%
760
31%
1378
November16th to endNight
45%
780
28%
2535
21%
780
56%
780
27%
1478
December1st to 15thNight
37%
780
22%
2535
14%
780
48%
780
20%
1614
December16th to endNight
31%
788
21%
2559
13%
788
42%
788
17%
1716

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
16%6%25%5%35%5%5%7%37%
48761
Night
15%5%2442445%7%42%
48273
TransparencyDay
44%6%11%17%15%4
48462
Night
39%6%12%19%16%4
48076
SeeingDay
19%7%17%22%18%13%
5767
Night
18%8%18%27%21%5%
15956

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
18%6%35%42325%443%
1611
16th to endDay
17%5%2441334447%
1728
February1st to 15thDay
16%7%2442335%5%44%
1720
16th to endDay
17%6%25%422337%43%
1580
March1st to 15thDay
19%6%1442445%6%41%
1929
16th to endDay
19%8%24324447%37%
2111
April1st to 15thDay
14%425%425%5%6%7%40%
2011
16th to endDay
17%5%25%5%34435%42%
2315
May1st to 15thDay
17%6%36%5%25%45%6%36%
2331
16th to endDay
15%5%25%5%45%5%6%9%32%
2431
June1st to 15thDay
12%6%37%7%47%6%7%8%27%
2340
16th to endDay
8%6%26%7%49%7%7%9%31%
2340
July1st to 15thDay
13%6%48%8%5%7%7%7%8%22%
2340
16th to endDay
11%439%8%5%8%7%9%9%24%
2465
August1st to 15thDay
14%6%37%7%48%7%8%9%22%
2340
16th to endDay
16%8%37%7%36%6%6%8%22%
2330
September1st to 15thDay
16%8%36%7%46%6%6%6%27%
1980
16th to endDay
18%5%25%6%45%5%47%34%
1980
October1st to 15thDay
16%5%12412335%51%
1923
16th to endDay
14%31232333456%
1920
November1st to 15thDay
14%422323346%52%
1762
16th to endDay
18%41332343448%
1755
December1st to 15thDay
20%7%2432444439%
1755
16th to endDay
25%6%24323345%39%
1764
January1st to 15thNight
18%6%23424345%44%
2327
16th to endNight
16%7%25%5%23445%43%
2496
February1st to 15thNight
15%5%14424346%47%
2132
16th to endNight
15%425%5%34346%42%
1893
March1st to 15thNight
17%6%2432435%7%42%
2029
16th to endNight
17%5%24424347%42%
2112
April1st to 15thNight
14%6%13323446%49%
1946
16th to endNight
14%6%23324347%46%
1644
May1st to 15thNight
16%5%25%5%345%46%40%
1619
16th to endNight
12%5%24425%5%6%8%42%
1682
June1st to 15thNight
10%4245%36%6%8%10%35%
1620
16th to endNight
7%3235%35%6%9%10%41%
1620
July1st to 15thNight
10%6%25%6%46%6%8%11%30%
1620
16th to endNight
9%435%5%36%7%8%11%33%
1703
August1st to 15thNight
15%7%26%5%35%6%6%8%31%
1620
16th to endNight
14%5%35%5%36%5%6%10%33%
1857
September1st to 15thNight
14%7%25%5%35%5%6%8%33%
1980
16th to endNight
17%6%24434446%41%
1980
October1st to 15thNight
15%413322345%51%
2037
16th to endNight
13%31332323457%
2304
November1st to 15thNight
13%5%24313346%52%
2423
16th to endNight
16%424323435%49%
2535
December1st to 15thNight
17%7%25%323445%41%
2535
16th to endNight
23%7%25%423446%35%
2559

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
43%48%16%21%6%
1612
16th to endDay
39%37%22%19%8%
1728
February1st to 15thDay
40%49%18%22%4
1722
16th to endDay
40%410%21%16%5%
1580
March1st to 15thDay
41%48%19%18%6%
1929
16th to endDay
45%5%13%17%14%3
2112
April1st to 15thDay
38%5%12%21%17%4
2011
16th to endDay
43%5%9%19%17%4
2315
May1st to 15thDay
47%6%12%17%13%2
2331
16th to endDay
45%9%15%18%9%1
2435
June1st to 15thDay
49%11%15%17%4
2340
16th to endDay
43%10%15%17%10%1
2340
July1st to 15thDay
53%11%15%13%5%
2201
16th to endDay
48%11%18%13%6%1
2310
August1st to 15thDay
51%11%14%15%5%
2327
16th to endDay
54%10%14%14%6%
2330
September1st to 15thDay
51%8%9%15%10%3
1980
16th to endDay
47%6%12%15%15%2
1980
October1st to 15thDay
35%5%9%18%24%6%
1923
16th to endDay
31%37%20%25%11%
1920
November1st to 15thDay
33%37%18%27%9%
1762
16th to endDay
37%36%18%26%7%
1755
December1st to 15thDay
44%39%16%18%7%
1755
16th to endDay
46%38%17%17%6%
1764
January1st to 15thNight
40%410%15%21%6%
2327
16th to endNight
41%29%19%20%6%
2496
February1st to 15thNight
36%311%21%21%6%
2141
16th to endNight
40%310%23%17%3
1893
March1st to 15thNight
40%6%10%19%16%6%
2029
16th to endNight
40%414%20%16%2
2112
April1st to 15thNight
34%311%26%19%4
1946
16th to endNight
36%5%13%20%19%4
1644
May1st to 15thNight
42%6%15%20%13%1
1620
16th to endNight
37%9%17%24%9%1
1684
June1st to 15thNight
38%12%22%20%5%
1620
16th to endNight
31%11%21%20%11%2
1620
July1st to 15thNight
43%11%20%16%7%
1530
16th to endNight
36%13%23%17%6%1
1595
August1st to 15thNight
46%10%15%15%10%
1609
16th to endNight
43%10%18%20%6%1
1857
September1st to 15thNight
44%9%15%17%10%2
1980
16th to endNight
41%6%12%19%16%2
1980
October1st to 15thNight
35%5%11%20%23%4
2037
16th to endNight
31%35%20%27%10%
2304
November1st to 15thNight
34%38%18%25%10%
2423
16th to endNight
35%36%20%24%9%
2535
December1st to 15thNight
43%410%16%17%8%
2535
16th to endNight
48%49%16%15%5%
2559

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
28%13%38%12%5%1
90
16th to endDay
23%33%30%10%2
96
February1st to 15thDay
25%28%41%4
90
16th to endDay
33%19%34%8%3
81
March1st to 15thDay
30%11%27%21%8%1
219
16th to endDay
25%13%24%22%11%2
288
April1st to 15thDay
18%13%22%26%15%3
270
16th to endDay
21%7%20%23%20%7%
270
May1st to 15thDay
19%17%20%17%15%11%
288
16th to endDay
21%6%14%23%15%18%
331
June1st to 15thDay
17%311%22%23%22%
315
16th to endDay
13%319%19%18%26%
315
July1st to 15thDay
10%212%24%22%26%
305
16th to endDay
8%6%23%27%32%
326
August1st to 15thDay
18%212%21%19%25%
313
16th to endDay
17%8%21%26%25%
332
September1st to 15thDay
15%5%12%17%31%17%
315
16th to endDay
21%18%26%28%13%
314
October1st to 15thDay
18%6%15%27%20%10%
315
16th to endDay
16%8%16%34%17%6%
336
November1st to 15thDay
23%7%23%28%13%2
180
16th to endDay
17%9%28%30%11%2
135
December1st to 15thDay
28%17%28%21%3
135
16th to endDay
36%10%37%12%2
108
January1st to 15thNight
26%14%25%25%7%
720
16th to endNight
20%16%31%27%3
768
February1st to 15thNight
22%14%29%31%2
704
16th to endNight
22%19%29%24%4
631
March1st to 15thNight
23%14%27%27%7%
720
16th to endNight
20%10%27%27%12%
768
April1st to 15thNight
19%14%23%26%13%1
688
16th to endNight
18%7%18%34%18%2
540
May1st to 15thNight
17%7%20%29%22%3
540
16th to endNight
15%311%27%31%10%
563
June1st to 15thNight
12%111%27%34%12%
540
16th to endNight
7%11%24%43%12%
540
July1st to 15thNight
9%17%22%47%10%
510
16th to endNight
10%6%19%45%16%
564
August1st to 15thNight
19%15%22%38%12%
539
16th to endNight
15%16%22%41%12%
588
September1st to 15thNight
16%29%25%35%11%
720
16th to endNight
20%27%31%31%5%
717
October1st to 15thNight
17%7%15%24%27%7%
720
16th to endNight
15%8%19%30%20%4
768
November1st to 15thNight
16%9%15%31%21%5%
760
16th to endNight
18%12%17%33%16%1
780
December1st to 15thNight
22%11%19%34%11%1
780
16th to endNight
28%10%24%29%6%
788
Page generated at 2017-12-21 07:04:56. Version ac04

Copyright 2017 A. Danko


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