Hawn State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hawn State Park clear sky chart from 2005-11-05 to 2017-09-21.

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
37%
15809
22%
46922
13%
15762
46%
15762
27%
29048

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
18%
900
21%
2473
5%
895
31%
895
20%
1644
January16th to endNight
17%
960
22%
2496
5%
960
29%
960
22%
1693
February1st to 15thNight
18%
812
17%
2220
5%
809
27%
809
18%
1565
February16th to endNight
19%
631
21%
1893
6%
631
31%
631
20%
1210
March1st to 15thNight
18%
660
17%
2100
7%
660
27%
660
18%
1418
March16th to endNight
26%
576
15%
2031
8%
576
36%
576
19%
1323
April1st to 15thNight
28%
539
23%
1797
11%
539
45%
539
25%
1035
April16th to endNight
33%
540
21%
1800
13%
540
46%
540
25%
1117
May1st to 15thNight
38%
540
18%
1709
11%
539
47%
539
27%
1085
May16th to endNight
45%
563
20%
1497
11%
561
51%
561
29%
1014
June1st to 15thNight
58%
540
22%
1440
15%
540
63%
540
43%
830
June16th to endNight
59%
540
25%
1440
16%
540
65%
540
46%
811
July1st to 15thNight
67%
510
19%
1360
15%
510
69%
510
42%
797
July16th to endNight
71%
564
22%
1511
20%
531
74%
531
41%
863
August1st to 15thNight
73%
539
23%
1700
27%
536
74%
536
41%
894
August16th to endNight
69%
573
25%
1910
28%
573
72%
573
36%
1033
September1st to 15thNight
60%
540
27%
1800
26%
540
66%
540
30%
1042
September16th to endNight
59%
632
32%
1832
22%
632
65%
632
36%
1063
October1st to 15thNight
48%
660
31%
1966
21%
660
57%
660
38%
1086
October16th to endNight
31%
704
27%
2117
14%
704
43%
704
30%
1239
November1st to 15thNight
34%
700
29%
2276
16%
700
50%
700
33%
1232
November16th to endNight
25%
726
23%
2346
14%
726
37%
726
21%
1447
December1st to 15thNight
20%
900
18%
2520
5%
900
31%
900
21%
1736
December16th to endNight
18%
960
19%
2688
5%
960
31%
960
19%
1871

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
12%5%245%35%5%5%7%42%
47947
Night
12%5%2442445%6%46%
47106
TransparencyDay
39%6%12%24%15%2
47634
Night
37%5%11%24%17%3
46924
SeeingDay
13%10%26%25%17%6%
5842
Night
15%13%29%26%13%2
15809

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
15%6%245%25%445%41%
1463
16th to endDay
11%7%36%5%3445%5%43%
1728
February1st to 15thDay
13%9%47%424446%38%
1642
16th to endDay
11%9%35%436%45%7%38%
1580
March1st to 15thDay
16%7%35%5%245%35%39%
1869
16th to endDay
17%9%46%5%35%5%5%5%32%
2191
April1st to 15thDay
12%5%245%2445%6%46%
2151
16th to endDay
18%6%35%5%34347%36%
2160
May1st to 15thDay
16%5%346%25%45%7%39%
2240
16th to endDay
10%6%25%5%346%6%8%39%
2617
June1st to 15thDay
7%315%5%35%46%9%45%
2520
16th to endDay
6%2135%36%5%7%9%48%
2520
July1st to 15thDay
10%3245%36%5%7%10%40%
2520
16th to endDay
5%2135%46%8%8%9%42%
2551
August1st to 15thDay
8%424436%6%7%10%41%
2250
16th to endDay
8%5%25%5%35%6%6%8%43%
2292
September1st to 15thDay
12%5%244345%5%9%44%
2160
16th to endDay
12%3135%235%5%7%48%
1908
October1st to 15thDay
11%415%323346%51%
1661
16th to endDay
12%413322335%55%
1755
November1st to 15thDay
10%6%24313346%52%
1582
16th to endDay
17%7%34424345%43%
1611
December1st to 15thDay
16%8%25%6%35%445%37%
1440
16th to endDay
15%10%345%2345%6%36%
1536
January1st to 15thNight
14%7%35%434445%42%
2473
16th to endNight
12%7%45%434346%42%
2496
February1st to 15thNight
14%10%46%5%24445%38%
2211
16th to endNight
11%6%36%6%24446%43%
1893
March1st to 15thNight
17%8%36%42434439%
2100
16th to endNight
16%7%35%5%24346%39%
2031
April1st to 15thNight
10%425%424446%50%
1797
16th to endNight
15%5%2442435%5%44%
1800
May1st to 15thNight
15%5%2332445%6%44%
1709
16th to endNight
8%425%6%46%5%5%8%42%
1496
June1st to 15thNight
7%31332446%8%52%
1440
16th to endNight
432432346%11%54%
1440
July1st to 15thNight
7%31332446%7%54%
1440
16th to endNight
5%313435%6%8%10%48%
1615
August1st to 15thNight
5%21332347%8%55%
1710
16th to endNight
5%225%5%245%5%9%52%
1910
September1st to 15thNight
10%4245%33436%50%
1800
16th to endNight
10%423324346%54%
1832
October1st to 15thNight
10%314313446%56%
1966
16th to endNight
16%42431223453%
2117
November1st to 15thNight
9%424223346%56%
2276
16th to endNight
16%7%2442333447%
2346
December1st to 15thNight
19%8%34423446%38%
2520
16th to endNight
15%10%35%42345%5%37%
2688

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%5%10%23%14%2
1464
16th to endDay
41%413%26%12%1
1728
February1st to 15thDay
46%412%23%12%1
1644
16th to endDay
44%414%22%11%2
1580
March1st to 15thDay
46%5%8%21%14%2
1869
16th to endDay
52%5%13%17%9%
2193
April1st to 15thDay
38%5%11%24%19%2
2151
16th to endDay
47%410%22%13%1
2160
May1st to 15thDay
43%7%12%23%12%
2240
16th to endDay
40%8%13%20%14%2
2621
June1st to 15thDay
33%7%13%24%18%2
2520
16th to endDay
29%7%15%24%19%3
2520
July1st to 15thDay
36%6%13%25%13%4
2371
16th to endDay
31%9%17%26%14%1
2392
August1st to 15thDay
33%8%14%26%15%1
2236
16th to endDay
35%7%13%22%16%4
2292
September1st to 15thDay
36%5%10%24%18%3
2160
16th to endDay
34%5%8%27%20%2
1908
October1st to 15thDay
33%5%9%26%20%4
1661
16th to endDay
31%38%32%19%4
1755
November1st to 15thDay
33%5%8%24%20%8%
1582
16th to endDay
42%48%25%16%1
1611
December1st to 15thDay
46%6%10%22%12%1
1440
16th to endDay
47%412%21%11%1
1536
January1st to 15thNight
43%49%24%16%1
2473
16th to endNight
42%411%24%15%1
2496
February1st to 15thNight
48%5%8%22%12%2
2220
16th to endNight
41%5%13%23%14%1
1893
March1st to 15thNight
48%49%19%15%3
2100
16th to endNight
46%414%23%10%
2031
April1st to 15thNight
34%412%26%18%2
1797
16th to endNight
41%39%26%16%2
1800
May1st to 15thNight
38%6%14%22%16%1
1710
16th to endNight
38%8%12%20%16%3
1498
June1st to 15thNight
27%415%30%19%2
1440
16th to endNight
23%6%14%28%20%6%
1440
July1st to 15thNight
28%5%14%29%15%5%
1360
16th to endNight
25%8%18%28%18%1
1511
August1st to 15thNight
24%6%15%28%22%2
1700
16th to endNight
27%6%12%24%23%5%
1910
September1st to 15thNight
35%46%28%19%6%
1800
16th to endNight
31%47%26%25%5%
1832
October1st to 15thNight
28%410%24%25%6%
1966
16th to endNight
34%38%27%20%4
2117
November1st to 15thNight
29%310%24%23%7%
2276
16th to endNight
41%47%24%19%2
2346
December1st to 15thNight
46%412%20%13%1
2520
16th to endNight
47%411%20%12%2
2688

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
33%23%36%5%1
90
16th to endDay
13%42%35%7%1
96
February1st to 15thDay
16%28%44%8%1
90
16th to endDay
23%29%32%13%1
81
March1st to 15thDay
35%16%36%8%11
90
16th to endDay
20%24%36%15%2
177
April1st to 15thDay
15%19%35%21%7%
270
16th to endDay
20%15%30%22%8%1
270
May1st to 15thDay
17%17%31%21%9%2
293
16th to endDay
13%9%35%24%11%4
517
June1st to 15thDay
9%427%29%21%7%
495
16th to endDay
6%6%33%32%15%5%
495
July1st to 15thDay
12%420%35%18%8%
475
16th to endDay
6%213%32%35%9%
515
August1st to 15thDay
12%14%26%30%14%
403
16th to endDay
11%214%30%28%12%
332
September1st to 15thDay
13%5%13%23%31%12%
315
16th to endDay
12%6%16%26%26%12%
275
October1st to 15thDay
11%7%33%35%7%2
101
16th to endDay
13%15%33%30%7%
96
November1st to 15thDay
414%32%27%12%8%
90
16th to endDay
35%21%26%10%6%
90
December1st to 15thDay
14%20%40%15%5%4
90
16th to endDay
25%29%37%7%1
96
January1st to 15thNight
20%27%31%17%2
900
16th to endNight
18%23%36%18%2
960
February1st to 15thNight
19%25%33%19%1
812
16th to endNight
16%23%38%19%2
631
March1st to 15thNight
25%18%34%18%2
660
16th to endNight
19%14%35%24%6%
576
April1st to 15thNight
13%19%35%25%6%
539
16th to endNight
18%9%35%26%9%
540
May1st to 15thNight
16%7%32%30%10%1
540
16th to endNight
9%5%31%34%16%3
563
June1st to 15thNight
9%223%39%23%1
540
16th to endNight
6%225%39%25%2
540
July1st to 15thNight
8%214%40%30%4
510
16th to endNight
6%112%36%35%6%
564
August1st to 15thNight
7%10%33%39%7%
539
16th to endNight
6%113%35%35%6%
573
September1st to 15thNight
11%414%32%31%6%
540
16th to endNight
13%5%16%28%29%7%
632
October1st to 15thNight
11%6%30%25%21%5%
660
16th to endNight
20%13%31%24%9%
704
November1st to 15thNight
12%14%36%25%10%1
700
16th to endNight
22%18%30%21%6%
726
December1st to 15thNight
24%17%34%18%4
900
16th to endNight
22%19%36%19%2
960
Page generated at 2017-09-22 06:35:30. Version ac04

Copyright 2017 A. Danko


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