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 2019-06-10.

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%
18157
22%
53890
13%
18110
46%
18110
27%
33509

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
19%
1050
21%
2887
6%
1045
31%
1045
19%
1944
January16th to endNight
17%
1120
21%
2912
5%
1120
29%
1120
22%
1977
February1st to 15thNight
17%
950
18%
2598
5%
947
26%
947
17%
1832
February16th to endNight
18%
735
20%
2205
6%
735
30%
735
18%
1451
March1st to 15thNight
18%
770
19%
2450
7%
770
29%
770
18%
1648
March16th to endNight
26%
672
15%
2369
8%
672
36%
672
18%
1552
April1st to 15thNight
30%
629
23%
2097
12%
629
45%
629
25%
1229
April16th to endNight
33%
624
20%
2078
13%
624
45%
624
24%
1297
May1st to 15thNight
40%
630
18%
1994
12%
629
48%
629
27%
1247
May16th to endNight
45%
659
19%
1753
11%
657
52%
657
30%
1176
June1st to 15thNight
58%
612
23%
1632
16%
612
63%
612
42%
947
June16th to endNight
60%
585
25%
1560
17%
585
66%
585
46%
880
July1st to 15thNight
70%
555
21%
1480
18%
555
71%
555
44%
852
July16th to endNight
70%
612
22%
1648
19%
579
73%
579
41%
933
August1st to 15thNight
74%
575
23%
1810
27%
572
75%
572
40%
962
August16th to endNight
68%
621
24%
2070
27%
621
71%
621
36%
1122
September1st to 15thNight
61%
585
28%
1950
27%
585
67%
585
31%
1128
September16th to endNight
58%
724
32%
2092
23%
724
64%
724
36%
1214
October1st to 15thNight
48%
780
30%
2324
20%
780
57%
780
36%
1307
October16th to endNight
31%
832
28%
2502
15%
832
44%
832
31%
1448
November1st to 15thNight
32%
820
28%
2666
16%
820
48%
820
29%
1514
November16th to endNight
27%
847
24%
2737
14%
847
40%
847
23%
1654
December1st to 15thNight
21%
1050
19%
2940
6%
1050
33%
1050
21%
2013
December16th to endNight
19%
1120
18%
3136
5%
1120
31%
1120
19%
2182

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%6%25%5%345%5%7%42%
54626
Night
12%6%2442445%6%46%
54074
TransparencyDay
39%6%12%24%15%2
54313
Night
38%411%24%17%3
53892
SeeingDay
15%11%26%24%15%5%
8085
Night
16%13%28%26%13%2
18157

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
16%8%25%5%25%445%39%
1709
16th to endDay
11%7%36%5%2345%6%43%
2016
February1st to 15thDay
15%8%36%42445%6%37%
1924
16th to endDay
13%9%45%435%45%7%35%
1840
March1st to 15thDay
16%8%36%5%24435%39%
2181
16th to endDay
18%9%46%5%35%5%5%5%31%
2556
April1st to 15thDay
12%6%25%5%2445%7%43%
2511
16th to endDay
19%6%35%5%34347%37%
2487
May1st to 15thDay
16%5%246%25%45%7%39%
2614
16th to endDay
10%5%25%5%346%6%9%40%
3065
June1st to 15thDay
8%315%5%35%46%9%45%
2857
16th to endDay
6%2135%36%6%8%10%46%
2730
July1st to 15thDay
9%3145%36%5%7%10%41%
2730
16th to endDay
5%3145%46%8%7%9%43%
2766
August1st to 15thDay
8%3245%36%6%7%10%41%
2393
16th to endDay
8%425%5%35%6%6%8%42%
2484
September1st to 15thDay
12%4244245%5%8%44%
2340
16th to endDay
11%3144245%5%7%49%
2184
October1st to 15thDay
11%5%25%424446%48%
1963
16th to endDay
13%413322336%54%
2073
November1st to 15thDay
12%6%25%313346%48%
1852
16th to endDay
15%8%34423335%44%
1879
December1st to 15thDay
15%9%246%35%445%38%
1680
16th to endDay
15%10%45%5%24446%35%
1792
January1st to 15thNight
14%8%35%434445%41%
2887
16th to endNight
12%7%45%5%3445%6%41%
2912
February1st to 15thNight
15%9%46%424445%38%
2589
16th to endNight
14%6%36%5%24445%41%
2205
March1st to 15thNight
17%8%36%42434440%
2450
16th to endNight
17%7%35%5%24346%38%
2369
April1st to 15thNight
10%425%424446%47%
2097
16th to endNight
16%5%2442435%5%44%
2078
May1st to 15thNight
14%5%233245%5%7%44%
1994
16th to endNight
8%425%5%46%5%5%9%42%
1752
June1st to 15thNight
7%32332446%9%51%
1632
16th to endNight
431432346%11%53%
1560
July1st to 15thNight
7%31332446%8%55%
1560
16th to endNight
5%3133346%8%10%49%
1752
August1st to 15thNight
5%21332347%8%55%
1820
16th to endNight
5%325%5%245%5%9%51%
2070
September1st to 15thNight
10%4245%33436%51%
1950
16th to endNight
10%424324346%54%
2092
October1st to 15thNight
10%314423447%54%
2324
16th to endNight
15%424312245%53%
2502
November1st to 15thNight
11%5%24323346%52%
2666
16th to endNight
14%7%24423345%48%
2737
December1st to 15thNight
18%8%34423346%39%
2940
16th to endNight
15%9%36%424445%37%
3136

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
46%5%9%22%13%2
1710
16th to endDay
42%414%24%13%1
2016
February1st to 15thDay
47%413%21%11%1
1926
16th to endDay
47%413%20%11%2
1840
March1st to 15thDay
46%5%8%20%14%4
2181
16th to endDay
53%5%12%18%9%
2558
April1st to 15thDay
39%5%12%23%17%1
2511
16th to endDay
47%410%22%12%2
2487
May1st to 15thDay
43%6%13%24%11%
2614
16th to endDay
39%8%14%21%13%2
3069
June1st to 15thDay
32%7%13%25%18%2
2857
16th to endDay
29%7%15%25%18%3
2730
July1st to 15thDay
35%6%14%25%13%4
2581
16th to endDay
31%8%16%27%13%1
2607
August1st to 15thDay
34%8%14%26%15%1
2379
16th to endDay
36%7%13%22%15%4
2484
September1st to 15thDay
36%5%10%24%18%3
2340
16th to endDay
33%6%8%27%21%2
2184
October1st to 15thDay
36%5%9%26%18%4
1963
16th to endDay
32%37%31%20%4
2073
November1st to 15thDay
36%5%8%24%18%7%
1852
16th to endDay
42%48%25%17%1
1879
December1st to 15thDay
46%5%9%23%13%1
1680
16th to endDay
48%411%21%11%1
1792
January1st to 15thNight
44%49%23%15%1
2887
16th to endNight
43%411%24%15%1
2912
February1st to 15thNight
48%49%21%13%2
2598
16th to endNight
44%412%21%14%2
2205
March1st to 15thNight
47%49%18%15%3
2450
16th to endNight
47%413%23%10%1
2369
April1st to 15thNight
36%412%26%17%2
2097
16th to endNight
41%39%25%16%3
2078
May1st to 15thNight
37%6%15%24%15%1
1995
16th to endNight
37%8%13%21%15%2
1754
June1st to 15thNight
28%415%29%19%2
1632
16th to endNight
23%6%14%30%19%5%
1560
July1st to 15thNight
27%415%30%15%5%
1480
16th to endNight
25%7%17%29%18%1
1648
August1st to 15thNight
24%6%15%28%21%2
1810
16th to endNight
28%6%13%25%22%4
2070
September1st to 15thNight
34%46%29%18%5%
1950
16th to endNight
31%47%27%24%4
2092
October1st to 15thNight
29%411%24%23%5%
2324
16th to endNight
33%38%27%22%5%
2502
November1st to 15thNight
33%410%23%21%6%
2666
16th to endNight
39%47%26%20%2
2737
December1st to 15thNight
46%411%21%14%1
2940
16th to endNight
47%5%11%20%12%2
3136

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
32%23%31%8%2
180
16th to endDay
14%40%33%10%1
192
February1st to 15thDay
27%25%37%8%2
180
16th to endDay
31%28%28%10%
159
March1st to 15thDay
32%21%37%7%1
180
16th to endDay
26%22%33%15%2
286
April1st to 15thDay
18%21%33%18%5%
390
16th to endDay
24%16%28%22%7%1
379
May1st to 15thDay
17%15%31%23%10%2
413
16th to endDay
12%9%35%24%12%4
677
June1st to 15thDay
9%426%30%22%7%
616
16th to endDay
5%6%31%33%17%5%
570
July1st to 15thDay
11%417%33%22%11%
550
16th to endDay
6%216%33%32%8%
595
August1st to 15thDay
12%14%28%31%12%
456
16th to endDay
11%217%31%26%10%
396
September1st to 15thDay
14%412%26%31%11%
375
16th to endDay
11%5%16%28%26%11%
374
October1st to 15thDay
17%6%33%34%5%2
193
16th to endDay
15%19%34%25%5%
192
November1st to 15thDay
16%17%33%21%6%4
180
16th to endDay
25%17%36%15%5%
180
December1st to 15thDay
21%26%32%12%5%2
180
16th to endDay
23%26%36%10%2
192
January1st to 15thNight
20%25%31%18%2
1050
16th to endNight
18%24%36%18%2
1120
February1st to 15thNight
19%25%33%18%2
950
16th to endNight
20%23%35%19%1
735
March1st to 15thNight
24%19%34%18%2
770
16th to endNight
20%14%34%25%5%
672
April1st to 15thNight
14%18%33%26%6%
629
16th to endNight
19%9%34%25%10%
624
May1st to 15thNight
16%7%32%31%11%1
630
16th to endNight
10%5%30%34%16%3
659
June1st to 15thNight
9%222%39%24%1
612
16th to endNight
6%224%40%24%1
585
July1st to 15thNight
8%113%37%32%6%
555
16th to endNight
6%113%36%35%6%
612
August1st to 15thNight
7%10%33%40%7%
575
16th to endNight
6%115%36%34%5%
621
September1st to 15thNight
12%313%30%32%6%
585
16th to endNight
12%5%16%27%28%8%
724
October1st to 15thNight
11%6%28%28%19%4
780
16th to endNight
18%13%32%23%10%
832
November1st to 15thNight
15%13%35%24%9%1
820
16th to endNight
20%18%30%21%7%
847
December1st to 15thNight
23%18%34%18%4
1050
16th to endNight
21%18%36%20%3
1120
Page generated at 2019-06-10 18:29:48. Version ac04

Copyright 2019 A. Danko


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