High Point State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the High Point State Park clear sky chart from 2005-11-05 to 2017-09-18.

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
30%
14986
18%
46864
8%
14955
41%
14955
20%
30209

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%
720
18%
2506
6%
716
34%
716
15%
1601
January16th to endNight
16%
768
19%
2583
4%
768
34%
768
14%
1651
February1st to 15thNight
13%
704
15%
2257
2%
701
29%
701
14%
1493
February16th to endNight
16%
631
24%
1893
6%
631
39%
631
16%
1216
March1st to 15thNight
17%
720
18%
2127
6%
720
32%
720
17%
1415
March16th to endNight
20%
768
21%
2010
7%
768
32%
768
20%
1329
April1st to 15thNight
20%
718
16%
1796
3%
718
27%
718
19%
1287
April16th to endNight
27%
720
17%
1800
4%
720
35%
720
25%
1226
May1st to 15thNight
27%
459
19%
1539
10%
459
37%
459
18%
1007
May16th to endNight
39%
374
15%
1497
12%
374
48%
374
18%
928
June1st to 15thNight
42%
360
14%
1440
12%
360
52%
360
18%
917
June16th to endNight
51%
360
14%
1440
13%
360
62%
360
26%
805
July1st to 15thNight
52%
340
13%
1360
17%
340
56%
340
23%
815
July16th to endNight
56%
376
15%
1418
16%
354
62%
354
24%
812
August1st to 15thNight
54%
543
18%
1614
12%
541
57%
541
32%
994
August16th to endNight
55%
764
19%
1910
10%
764
57%
764
32%
1280
September1st to 15thNight
44%
720
22%
1800
10%
720
50%
720
31%
1184
September16th to endNight
50%
669
26%
1820
18%
669
56%
669
33%
1121
October1st to 15thNight
36%
660
21%
1958
14%
660
45%
660
24%
1285
October16th to endNight
26%
704
19%
2184
8%
704
41%
704
22%
1371
November1st to 15thNight
30%
700
20%
2277
10%
700
45%
700
22%
1409
November16th to endNight
26%
720
19%
2427
10%
720
39%
720
18%
1552
December1st to 15thNight
22%
720
14%
2520
6%
720
32%
720
13%
1704
December16th to endNight
16%
768
16%
2688
3%
768
31%
768
12%
1807

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%3445%7%37%
47933
Night
15%6%2442445%7%41%
47034
Cloud CoverDay
16%6%25%5%3445%7%37%
47942
Night
15%6%2442445%7%41%
47040
TransparencyDay
44%6%12%20%13%1
47621
Night
41%6%13%22%14%1
46864
SeeingDay
21%14%27%20%11%4
5723
Night
20%15%28%24%9%
14987

By Month

Percentage Cloud Cover NE (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
14%6%36%5%25%5%6%5%39%
1432
16th to endDay
13%8%35%4245%6%6%37%
1640
February1st to 15thDay
14%7%37%7%3445%6%33%
1603
16th to endDay
14%7%37%5%35%35%6%37%
1580
March1st to 15thDay
16%7%35%5%3445%7%34%
1820
16th to endDay
16%7%345%24446%38%
2214
April1st to 15thDay
19%7%35%424346%40%
2152
16th to endDay
16%5%25%5%34346%42%
2160
May1st to 15thDay
21%6%245%34446%34%
2421
16th to endDay
16%5%346%35%46%7%35%
2618
June1st to 15thDay
19%435%5%35%45%8%33%
2520
16th to endDay
13%5%36%6%35%5%5%9%34%
2520
July1st to 15thDay
12%6%25%6%36%5%6%8%34%
2520
16th to endDay
10%5%25%6%25%6%7%9%38%
2654
August1st to 15thDay
13%5%25%6%45%5%7%8%34%
2320
16th to endDay
13%5%25%5%35%45%8%41%
2292
September1st to 15thDay
15%5%24335%45%7%42%
2160
16th to endDay
14%5%25%42445%6%45%
1865
October1st to 15thDay
18%7%245%23447%39%
1669
16th to endDay
20%5%2343445%7%37%
1686
November1st to 15thDay
16%7%3332325%5%45%
1581
16th to endDay
18%6%233235%37%41%
1530
December1st to 15thDay
16%7%35%6%245%5%7%35%
1440
16th to endDay
19%8%345%3446%8%31%
1536
January1st to 15thNight
16%6%3443445%7%39%
2506
16th to endNight
13%8%25%4345%5%6%40%
2583
February1st to 15thNight
13%7%36%5%35%446%38%
2256
16th to endNight
15%6%25%42435%6%42%
1893
March1st to 15thNight
17%7%24424347%41%
2114
16th to endNight
16%6%3432335%8%41%
2010
April1st to 15thNight
17%6%35%5%35%447%36%
1796
16th to endNight
17%5%25%5%2435%5%42%
1800
May1st to 15thNight
18%7%35%42445%6%38%
1539
16th to endNight
15%5%245%25%45%8%40%
1495
June1st to 15thNight
19%424325%448%39%
1440
16th to endNight
11%315%3245%5%9%46%
1440
July1st to 15thNight
11%4245%35%45%9%43%
1440
16th to endNight
11%313425%6%6%10%43%
1514
August1st to 15thNight
11%5%243235%5%9%46%
1624
16th to endNight
13%424435%5%5%7%44%
1910
September1st to 15thNight
15%414324446%47%
1800
16th to endNight
12%5%33424336%50%
1820
October1st to 15thNight
19%5%23433335%44%
1958
16th to endNight
20%41431245%7%43%
2184
November1st to 15thNight
15%7%25%323346%45%
2277
16th to endNight
16%6%245%2445%6%40%
2427
December1st to 15thNight
19%6%345%3445%6%34%
2520
16th to endNight
18%7%25%5%35%35%7%35%
2688

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
14%6%36%6%345%5%6%38%
1432
16th to endDay
13%7%35%5%3445%7%38%
1640
February1st to 15thDay
15%7%36%6%3445%7%33%
1603
16th to endDay
14%8%26%5%35%446%37%
1580
March1st to 15thDay
16%7%35%5%3436%8%34%
1830
16th to endDay
16%7%345%24445%39%
2213
April1st to 15thDay
19%8%34323336%40%
2152
16th to endDay
16%5%35%5%3435%6%42%
2160
May1st to 15thDay
21%6%245%34446%34%
2421
16th to endDay
16%6%35%5%35%5%5%7%35%
2618
June1st to 15thDay
19%5%35%5%25%5%5%8%33%
2520
16th to endDay
13%5%36%6%35%5%5%8%35%
2520
July1st to 15thDay
12%5%26%6%46%5%6%8%34%
2520
16th to endDay
10%6%25%6%35%5%7%8%38%
2654
August1st to 15thDay
13%5%16%6%45%5%6%8%34%
2320
16th to endDay
14%4245%25%45%7%42%
2292
September1st to 15thDay
15%5%24435%45%7%42%
2160
16th to endDay
13%5%15%433447%45%
1865
October1st to 15thDay
18%6%2442345%6%39%
1669
16th to endDay
21%5%145%2445%6%38%
1686
November1st to 15thDay
17%7%24412346%44%
1581
16th to endDay
18%6%2332445%6%41%
1530
December1st to 15thDay
16%7%36%5%25%45%6%36%
1440
16th to endDay
19%9%345%35%45%7%32%
1536
January1st to 15thNight
16%6%245%2446%6%39%
2506
16th to endNight
14%8%25%4345%5%6%39%
2583
February1st to 15thNight
13%7%36%5%35%45%6%38%
2249
16th to endNight
15%5%35%424447%42%
1893
March1st to 15thNight
17%6%2442335%7%40%
2127
16th to endNight
16%6%24423447%41%
2010
April1st to 15thNight
17%6%35%5%34448%36%
1796
16th to endNight
17%5%25%423446%42%
1800
May1st to 15thNight
17%8%25%42445%5%39%
1539
16th to endNight
14%5%2443446%7%40%
1495
June1st to 15thNight
19%5%23425%45%7%39%
1440
16th to endNight
11%315%425%5%5%8%46%
1440
July1st to 15thNight
11%4245%35%5%5%8%42%
1440
16th to endNight
11%313435%6%6%10%43%
1514
August1st to 15thNight
11%5%143245%49%46%
1624
16th to endNight
13%324434447%44%
1910
September1st to 15thNight
15%42432345%6%48%
1800
16th to endNight
12%5%24423346%50%
1820
October1st to 15thNight
18%6%24323345%44%
1958
16th to endNight
19%5%1431335%7%44%
2184
November1st to 15thNight
15%6%34313346%45%
2277
16th to endNight
16%6%2443435%6%41%
2427
December1st to 15thNight
19%7%345%3446%6%34%
2520
16th to endNight
18%7%25%435%35%7%35%
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
44%5%13%23%10%2
1433
16th to endDay
43%5%13%22%12%2
1640
February1st to 15thDay
49%5%11%20%11%1
1606
16th to endDay
45%6%10%23%12%1
1580
March1st to 15thDay
46%5%14%21%9%1
1830
16th to endDay
45%5%9%19%16%2
2214
April1st to 15thDay
45%5%9%22%12%4
2152
16th to endDay
43%49%20%18%3
2160
May1st to 15thDay
50%5%9%19%13%2
2421
16th to endDay
46%8%13%17%12%1
2622
June1st to 15thDay
47%8%13%19%10%
2520
16th to endDay
44%8%12%22%11%
2520
July1st to 15thDay
45%7%10%19%14%1
2371
16th to endDay
39%9%14%21%11%2
2487
August1st to 15thDay
43%9%13%19%13%
2306
16th to endDay
39%6%11%25%15%1
2292
September1st to 15thDay
41%6%11%20%18%1
2160
16th to endDay
38%49%22%21%2
1865
October1st to 15thDay
44%5%12%19%15%2
1669
16th to endDay
44%5%12%22%13%1
1686
November1st to 15thDay
41%414%19%16%3
1581
16th to endDay
42%5%10%25%13%1
1530
December1st to 15thDay
47%5%17%18%9%1
1440
16th to endDay
50%6%14%17%9%
1536
January1st to 15thNight
43%5%15%20%12%2
2506
16th to endNight
42%6%12%24%12%1
2583
February1st to 15thNight
45%5%15%19%12%1
2257
16th to endNight
40%49%25%16%1
1893
March1st to 15thNight
43%5%14%22%12%2
2127
16th to endNight
41%412%21%17%2
2010
April1st to 15thNight
46%6%9%19%15%2
1796
16th to endNight
42%410%21%19%2
1800
May1st to 15thNight
44%5%11%19%16%1
1539
16th to endNight
40%8%16%19%12%2
1497
June1st to 15thNight
43%7%13%22%12%
1440
16th to endNight
33%7%16%29%12%
1440
July1st to 15thNight
37%7%14%23%13%2
1360
16th to endNight
32%10%17%22%14%2
1418
August1st to 15thNight
33%7%15%26%15%1
1614
16th to endNight
37%7%12%21%19%1
1910
September1st to 15thNight
37%5%11%25%19%
1800
16th to endNight
34%48%23%26%1
1820
October1st to 15thNight
42%411%22%17%1
1958
16th to endNight
39%5%15%25%13%
2184
November1st to 15thNight
40%414%20%17%3
2277
16th to endNight
43%5%14%23%12%1
2427
December1st to 15thNight
47%6%15%19%10%
2520
16th to endNight
48%5%14%21%9%
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
31%31%20%13%3
60
16th to endDay
32%22%35%8%1
81
February1st to 15thDay
28%35%26%10%
120
16th to endDay
24%23%33%14%2
239
March1st to 15thDay
25%23%27%17%6%
270
16th to endDay
23%22%31%11%7%2
288
April1st to 15thDay
27%20%27%16%7%1
270
16th to endDay
22%15%31%15%9%5%
270
May1st to 15thDay
35%15%22%13%9%3
288
16th to endDay
18%12%29%23%12%3
331
June1st to 15thDay
23%13%25%22%13%1
315
16th to endDay
17%12%32%24%11%1
315
July1st to 15thDay
15%9%28%28%15%2
305
16th to endDay
12%7%25%28%23%4
326
August1st to 15thDay
14%7%25%28%14%9%
313
16th to endDay
14%6%21%25%21%11%
332
September1st to 15thDay
15%11%26%19%15%10%
315
16th to endDay
19%323%20%17%15%
262
October1st to 15thDay
23%8%21%25%13%6%
255
16th to endDay
22%17%30%19%9%
259
November1st to 15thDay
22%16%21%27%8%2
235
16th to endDay
24%22%30%15%6%1
150
December1st to 15thDay
25%30%23%16%31
60
16th to endDay
34%28%28%7%1
64
January1st to 15thNight
22%21%33%19%3
720
16th to endNight
22%23%34%18%1
768
February1st to 15thNight
21%23%37%17%
704
16th to endNight
25%23%31%16%2
631
March1st to 15thNight
25%23%30%17%2
720
16th to endNight
21%23%29%18%5%1
768
April1st to 15thNight
22%21%33%19%3
718
16th to endNight
20%16%30%23%8%
720
May1st to 15thNight
24%10%31%26%6%
459
16th to endNight
16%9%31%30%12%
375
June1st to 15thNight
21%5%23%36%12%
360
16th to endNight
11%327%47%9%
360
July1st to 15thNight
13%5%22%42%16%
340
16th to endNight
11%223%41%19%1
376
August1st to 15thNight
13%124%36%21%1
543
16th to endNight
14%319%32%27%1
764
September1st to 15thNight
17%7%24%31%16%2
720
16th to endNight
14%5%23%27%24%5%
669
October1st to 15thNight
21%9%26%27%14%
660
16th to endNight
23%15%31%23%5%
704
November1st to 15thNight
21%16%27%24%9%1
700
16th to endNight
20%20%27%22%8%
720
December1st to 15thNight
25%20%28%19%5%
720
16th to endNight
25%23%31%17%2
768
Page generated at 2017-09-19 07:32:25. Version ac04

Copyright 2017 A. Danko


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