Half Hollow Hills
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Half Hollow Hills clear sky chart from 2005-11-05 to 2018-03-11.

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
35%
15730
19%
49087
10%
15699
45%
15699
23%
31732

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
21%
780
21%
2716
8%
776
38%
776
20%
1683
January16th to endNight
19%
832
20%
2840
6%
832
37%
832
20%
1770
February1st to 15thNight
18%
764
17%
2382
4%
761
33%
761
19%
1590
February16th to endNight
22%
683
24%
2049
9%
683
41%
683
22%
1314
March1st to 15thNight
23%
764
18%
2291
8%
764
37%
764
23%
1519
March16th to endNight
25%
768
24%
1995
9%
768
37%
768
27%
1313
April1st to 15thNight
31%
718
17%
1796
7%
718
36%
718
25%
1265
April16th to endNight
35%
681
18%
1761
5%
681
41%
681
26%
1214
May1st to 15thNight
30%
537
16%
1617
7%
537
37%
537
20%
1132
May16th to endNight
44%
374
15%
1497
13%
374
51%
374
17%
972
June1st to 15thNight
45%
360
14%
1440
15%
360
52%
360
18%
935
June16th to endNight
62%
360
15%
1440
19%
360
67%
360
24%
847
July1st to 15thNight
55%
340
12%
1360
16%
340
56%
340
20%
829
July16th to endNight
61%
376
16%
1418
18%
354
66%
354
22%
852
August1st to 15thNight
59%
552
18%
1623
14%
550
62%
550
31%
991
August16th to endNight
62%
764
18%
1910
11%
764
64%
764
33%
1273
September1st to 15thNight
52%
720
22%
1812
13%
720
55%
720
32%
1202
September16th to endNight
52%
717
24%
1980
18%
717
57%
717
30%
1286
October1st to 15thNight
40%
720
20%
2073
14%
720
47%
720
25%
1366
October16th to endNight
31%
768
21%
2422
11%
768
45%
768
24%
1531
November1st to 15thNight
33%
760
20%
2472
11%
760
47%
760
23%
1552
November16th to endNight
28%
780
20%
2551
10%
780
41%
780
22%
1596
December1st to 15thNight
24%
780
15%
2730
6%
780
36%
780
16%
1805
December16th to endNight
18%
832
19%
2912
5%
832
35%
832
18%
1895

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
15%6%2442445%7%41%
49542
Night
16%6%24424446%42%
49257
Cloud CoverDay
16%5%2442445%7%41%
49552
Night
17%6%24424446%42%
49262
TransparencyDay
40%6%12%22%15%1
49230
Night
42%5%12%22%15%2
49087
SeeingDay
19%6%27%28%15%3
6374
Night
20%8%30%28%11%1
15731

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
15%6%25%424346%43%
1552
16th to endDay
14%7%36%43335%6%41%
1732
February1st to 15thDay
16%6%35%5%34346%40%
1807
16th to endDay
16%6%24424445%42%
1710
March1st to 15thDay
17%7%25%3245%5%8%37%
1896
16th to endDay
17%6%24424336%43%
2224
April1st to 15thDay
18%7%34423437%40%
2152
16th to endDay
17%41442445%6%43%
2199
May1st to 15thDay
21%7%2442345%7%37%
2343
16th to endDay
17%5%1442446%9%38%
2618
June1st to 15thDay
20%5%245%2345%7%37%
2520
16th to endDay
10%5%25%5%35%5%6%8%42%
2520
July1st to 15thDay
10%5%245%35%6%6%9%40%
2520
16th to endDay
11%5%25%435%6%7%8%39%
2654
August1st to 15thDay
12%4235%346%6%9%41%
2313
16th to endDay
12%425%42445%8%44%
2292
September1st to 15thDay
13%4144345%47%46%
2148
16th to endDay
15%5%25%424346%44%
1980
October1st to 15thDay
17%6%25%423347%41%
1885
16th to endDay
17%5%24423446%44%
1800
November1st to 15thDay
20%5%25%323435%44%
1716
16th to endDay
14%6%24334447%45%
1737
December1st to 15thDay
16%7%35%4235%5%6%39%
1560
16th to endDay
20%9%24323446%37%
1664
January1st to 15thNight
18%5%25%423336%44%
2716
16th to endNight
17%7%24323436%43%
2840
February1st to 15thNight
16%8%35%424446%39%
2381
16th to endNight
18%5%23424445%43%
2049
March1st to 15thNight
18%6%24424446%42%
2278
16th to endNight
16%7%24423346%44%
1995
April1st to 15thNight
17%6%245%24446%39%
1796
16th to endNight
19%6%35%423346%41%
1761
May1st to 15thNight
17%8%25%5%34446%36%
1617
16th to endNight
20%6%2442435%8%36%
1495
June1st to 15thNight
20%6%2442345%8%38%
1440
16th to endNight
10%5%25%5%25%5%6%8%43%
1440
July1st to 15thNight
11%435%5%346%7%8%38%
1440
16th to endNight
9%5%35%5%26%5%7%9%39%
1514
August1st to 15thNight
9%414435%5%6%8%45%
1633
16th to endNight
12%4244345%6%8%43%
1910
September1st to 15thNight
15%324425%45%6%46%
1812
16th to endNight
14%5%25%433336%47%
1980
October1st to 15thNight
16%7%25%422335%44%
2073
16th to endNight
18%5%1442325%6%44%
2422
November1st to 15thNight
17%6%24424335%45%
2472
16th to endNight
17%5%2442445%6%43%
2551
December1st to 15thNight
19%6%25%424447%37%
2730
16th to endNight
19%6%25%324445%38%
2912

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%5%25%424346%43%
1552
16th to endDay
15%6%35%423348%41%
1732
February1st to 15thDay
16%5%35%5%23446%40%
1807
16th to endDay
17%426%424445%42%
1710
March1st to 15thDay
18%5%35%42445%8%37%
1906
16th to endDay
17%6%24424346%42%
2224
April1st to 15thDay
18%6%34424446%40%
2152
16th to endDay
17%6%2442445%6%42%
2199
May1st to 15thDay
21%6%25%423448%36%
2343
16th to endDay
17%5%1442446%9%38%
2618
June1st to 15thDay
20%5%25%42345%8%36%
2520
16th to endDay
10%425%5%25%5%6%8%42%
2520
July1st to 15thDay
10%5%25%435%6%7%9%40%
2520
16th to endDay
11%5%25%5%245%6%9%39%
2654
August1st to 15thDay
11%5%244345%7%9%42%
2313
16th to endDay
12%42442445%8%44%
2292
September1st to 15thDay
12%425%42445%7%46%
2148
16th to endDay
14%6%24422347%44%
1980
October1st to 15thDay
17%5%24424347%42%
1885
16th to endDay
16%424324447%44%
1800
November1st to 15thDay
19%5%23423335%44%
1716
16th to endDay
14%5%24424347%45%
1737
December1st to 15thDay
17%7%343345%5%6%40%
1560
16th to endDay
21%9%24323346%37%
1664
January1st to 15thNight
18%5%24423346%44%
2716
16th to endNight
18%7%23324336%43%
2840
February1st to 15thNight
15%8%25%42445%5%39%
2374
16th to endNight
18%6%24424445%44%
2049
March1st to 15thNight
18%6%24423346%42%
2291
16th to endNight
16%7%24322446%44%
1994
April1st to 15thNight
19%5%35%424446%39%
1796
16th to endNight
19%7%34423346%40%
1761
May1st to 15thNight
18%8%25%5%345%5%5%35%
1617
16th to endNight
19%7%2442346%7%36%
1495
June1st to 15thNight
21%6%2441435%7%38%
1440
16th to endNight
10%4245%35%5%5%9%42%
1440
July1st to 15thNight
11%5%25%425%5%7%10%37%
1440
16th to endNight
9%5%25%5%45%5%6%10%38%
1514
August1st to 15thNight
9%424435%5%7%9%44%
1633
16th to endNight
13%415%435%5%5%8%42%
1910
September1st to 15thNight
14%4143345%5%6%45%
1812
16th to endNight
15%5%25%5%23336%47%
1980
October1st to 15thNight
16%8%24323346%44%
2073
16th to endNight
19%424323346%45%
2422
November1st to 15thNight
16%6%24424345%45%
2472
16th to endNight
17%5%2442445%6%43%
2551
December1st to 15thNight
20%5%25%424446%37%
2730
16th to endNight
19%6%25%42345%5%39%
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
41%5%13%24%11%3
1553
16th to endDay
42%413%24%12%2
1732
February1st to 15thDay
44%414%20%14%1
1810
16th to endDay
42%411%25%13%1
1710
March1st to 15thDay
43%6%15%21%11%1
1906
16th to endDay
43%410%22%16%2
2224
April1st to 15thDay
43%6%9%21%16%3
2152
16th to endDay
40%5%9%21%19%3
2199
May1st to 15thDay
46%6%9%20%15%1
2343
16th to endDay
42%8%15%19%12%2
2622
June1st to 15thDay
45%7%12%21%12%
2520
16th to endDay
36%8%14%23%15%1
2520
July1st to 15thDay
38%8%12%22%16%1
2371
16th to endDay
36%9%14%24%12%2
2487
August1st to 15thDay
35%8%15%22%16%1
2299
16th to endDay
35%7%10%23%20%1
2292
September1st to 15thDay
35%7%13%21%21%1
2148
16th to endDay
39%5%8%21%22%1
1980
October1st to 15thDay
42%5%11%20%18%1
1885
16th to endDay
38%6%11%24%17%1
1800
November1st to 15thDay
42%413%19%17%1
1716
16th to endDay
38%5%13%25%14%2
1737
December1st to 15thDay
43%5%17%17%14%
1560
16th to endDay
48%5%15%18%11%
1664
January1st to 15thNight
41%412%24%14%3
2716
16th to endNight
42%412%23%15%1
2840
February1st to 15thNight
45%6%12%21%13%2
2382
16th to endNight
41%49%23%17%3
2049
March1st to 15thNight
44%413%20%13%3
2291
16th to endNight
40%49%22%17%4
1995
April1st to 15thNight
44%6%10%19%15%2
1796
16th to endNight
44%5%8%16%20%3
1761
May1st to 15thNight
48%6%10%17%14%2
1617
16th to endNight
45%7%13%18%13%1
1497
June1st to 15thNight
46%5%10%19%16%
1440
16th to endNight
36%8%13%26%14%1
1440
July1st to 15thNight
39%8%13%22%13%1
1360
16th to endNight
37%9%13%26%11%2
1418
August1st to 15thNight
33%7%14%25%16%1
1623
16th to endNight
37%7%12%24%17%1
1910
September1st to 15thNight
38%5%10%25%18%1
1812
16th to endNight
40%47%20%24%2
1980
October1st to 15thNight
42%5%10%22%16%2
2073
16th to endNight
41%413%23%16%1
2422
November1st to 15thNight
41%411%20%18%3
2472
16th to endNight
41%413%25%12%2
2551
December1st to 15thNight
47%5%15%18%11%
2730
16th to endNight
45%414%21%12%1
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
15%18%38%21%5%
90
16th to endDay
22%6%41%24%5%
112
February1st to 15thDay
24%11%41%20%1
233
16th to endDay
20%11%39%20%6%
291
March1st to 15thDay
21%11%39%23%4
312
16th to endDay
20%11%40%20%5%1
288
April1st to 15thDay
21%8%31%25%12%
270
16th to endDay
25%428%29%11%1
270
May1st to 15thDay
30%6%30%21%8%2
288
16th to endDay
20%320%33%19%2
331
June1st to 15thDay
22%5%22%27%19%2
315
16th to endDay
15%27%37%16%1
315
July1st to 15thDay
14%17%42%22%2
305
16th to endDay
11%216%37%26%4
326
August1st to 15thDay
15%16%34%28%5%
313
16th to endDay
12%211%42%22%8%
332
September1st to 15thDay
16%224%26%23%7%
315
16th to endDay
19%417%26%20%11%
314
October1st to 15thDay
23%419%27%18%7%
315
16th to endDay
14%11%32%26%14%1
306
November1st to 15thDay
21%10%25%26%13%1
280
16th to endDay
15%15%28%27%10%1
267
December1st to 15thDay
21%14%34%20%10%
90
16th to endDay
29%16%38%14%1
96
January1st to 15thNight
20%14%38%21%3
780
16th to endNight
23%12%41%21%1
832
February1st to 15thNight
20%13%42%21%1
764
16th to endNight
22%15%36%23%3
683
March1st to 15thNight
21%12%39%21%5%
764
16th to endNight
20%11%38%23%6%
768
April1st to 15thNight
21%8%34%28%6%
718
16th to endNight
21%6%32%31%7%
681
May1st to 15thNight
21%5%35%27%9%
537
16th to endNight
23%320%36%15%1
375
June1st to 15thNight
23%218%35%20%
360
16th to endNight
11%119%48%17%1
360
July1st to 15thNight
15%218%42%20%1
340
16th to endNight
11%116%45%22%2
376
August1st to 15thNight
12%118%43%22%1
552
16th to endNight
16%112%35%30%4
764
September1st to 15thNight
17%122%35%18%3
720
16th to endNight
19%118%31%23%5%
717
October1st to 15thNight
21%6%26%25%16%2
720
16th to endNight
21%9%32%25%10%
768
November1st to 15thNight
18%10%32%23%13%2
760
16th to endNight
19%11%33%24%9%
780
December1st to 15thNight
24%13%32%20%7%1
780
16th to endNight
23%14%40%19%2
832
Page generated at 2018-03-12 13:28:14. Version ac04

Copyright 2018 A. Danko


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