Honea-Egypt Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Honea-Egypt Observatory clear sky chart from 2005-11-05 to 2018-11-30.

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
49%
16977
24%
51711
17%
16928
56%
16928
31%
30955

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
32%
975
25%
2522
10%
970
41%
970
28%
1651
January16th to endNight
29%
1040
25%
2704
9%
1040
38%
1040
28%
1789
February1st to 15thNight
29%
839
22%
2362
9%
833
37%
833
24%
1559
February16th to endNight
23%
578
24%
1944
9%
578
36%
578
21%
1231
March1st to 15thNight
30%
585
25%
2145
14%
585
43%
585
21%
1321
March16th to endNight
33%
624
22%
2288
15%
624
44%
624
25%
1308
April1st to 15thNight
31%
584
21%
2110
13%
584
45%
584
25%
1246
April16th to endNight
35%
579
23%
1928
16%
579
47%
579
27%
1142
May1st to 15thNight
38%
584
21%
1825
16%
584
47%
584
27%
1113
May16th to endNight
56%
611
24%
1828
22%
609
64%
609
38%
1041
June1st to 15thNight
75%
585
21%
1755
23%
585
79%
585
47%
914
June16th to endNight
71%
585
18%
1755
19%
585
75%
585
36%
1028
July1st to 15thNight
80%
555
17%
1665
20%
555
82%
555
40%
930
July16th to endNight
83%
612
19%
1738
24%
579
84%
579
41%
963
August1st to 15thNight
89%
575
27%
1717
30%
572
89%
572
58%
802
August16th to endNight
78%
621
16%
2089
18%
621
79%
621
29%
1251
September1st to 15thNight
71%
585
16%
2145
18%
585
73%
585
27%
1288
September16th to endNight
68%
582
27%
2145
28%
582
71%
582
31%
1189
October1st to 15thNight
70%
708
32%
2268
29%
708
72%
708
44%
1142
October16th to endNight
53%
832
34%
2496
23%
832
61%
832
40%
1360
November1st to 15thNight
46%
820
27%
2460
18%
820
53%
820
32%
1475
November16th to endNight
44%
903
31%
2583
18%
903
53%
903
33%
1544
December1st to 15thNight
35%
975
24%
2535
11%
975
42%
975
25%
1749
December16th to endNight
32%
1040
19%
2704
8%
1040
38%
1040
22%
1919

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%25%5%35%5%5%7%40%
52579
Night
12%5%2442345%7%48%
51912
TransparencyDay
42%6%11%17%15%6%
52279
Night
34%5%13%20%16%8%
51717
SeeingDay
12%6%18%27%24%10%
6940
Night
15%6%23%32%19%2
16978

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
19%5%23423346%44%
1746
16th to endDay
19%6%24323335%45%
1872
February1st to 15thDay
20%6%34423346%41%
1835
16th to endDay
20%7%45%5%23235%39%
1814
March1st to 15thDay
22%6%24423345%39%
2145
16th to endDay
16%6%35%424346%43%
2286
April1st to 15thDay
17%5%25%5%34446%40%
2168
16th to endDay
14%6%25%43445%7%40%
2307
May1st to 15thDay
12%6%26%6%46%5%5%7%36%
2452
16th to endDay
8%6%36%6%36%6%7%8%36%
2638
June1st to 15thDay
5%3245%5%6%7%8%10%39%
2535
16th to endDay
8%426%6%5%8%7%9%9%30%
2535
July1st to 15thDay
10%425%7%47%6%7%10%33%
2535
16th to endDay
6%437%7%5%7%6%8%10%32%
2674
August1st to 15thDay
42146%46%6%7%10%44%
2486
16th to endDay
8%426%7%5%7%7%7%9%33%
2460
September1st to 15thDay
10%5%35%6%36%6%6%8%36%
2145
16th to endDay
9%5%36%6%46%5%6%7%39%
2145
October1st to 15thDay
9%31443445%6%51%
2008
16th to endDay
12%41332334457%
2080
November1st to 15thDay
10%6%26%4245%6%6%44%
2058
16th to endDay
13%5%3442333450%
2028
December1st to 15thDay
17%8%36%6%34335%37%
1755
16th to endDay
20%8%35%5%23345%35%
1872
January1st to 15thNight
18%7%23212345%46%
2522
16th to endNight
19%5%24413336%45%
2704
February1st to 15thNight
18%7%25%413335%43%
2357
16th to endNight
19%5%24423345%43%
1944
March1st to 15thNight
19%6%24323346%42%
2145
16th to endNight
12%7%24323346%48%
2288
April1st to 15thNight
11%6%245%235%5%7%46%
2110
16th to endNight
13%5%2342345%7%47%
1928
May1st to 15thNight
11%4145%2446%8%44%
1824
16th to endNight
6%32332446%10%51%
1827
June1st to 15thNight
3223235%6%10%57%
1755
16th to endNight
5%324325%5%7%11%47%
1755
July1st to 15thNight
5%2233145%6%12%51%
1755
16th to endNight
3213325%6%7%12%51%
1846
August1st to 15thNight
21121337%13%61%
1727
16th to endNight
6%2145%35%7%6%10%45%
2089
September1st to 15thNight
8%5%15%5%345%5%8%45%
2145
16th to endNight
8%415%4245%6%9%48%
2145
October1st to 15thNight
6%313223348%60%
2268
16th to endNight
11%5%1231223461%
2496
November1st to 15thNight
11%6%14424346%49%
2460
16th to endNight
13%42432334453%
2583
December1st to 15thNight
18%7%25%424345%41%
2535
16th to endNight
19%9%35%413336%38%
2704

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
42%36%14%21%10%
1747
16th to endDay
43%25%14%21%13%
1872
February1st to 15thDay
45%35%16%16%11%
1836
16th to endDay
49%47%12%16%9%
1814
March1st to 15thDay
47%37%13%20%6%
2145
16th to endDay
44%38%15%21%6%
2288
April1st to 15thDay
45%45%17%16%9%
2168
16th to endDay
43%49%18%17%7%
2307
May1st to 15thDay
47%6%9%16%13%6%
2452
16th to endDay
41%8%11%21%14%2
2642
June1st to 15thDay
37%7%15%22%16%1
2535
16th to endDay
47%8%15%18%9%
2535
July1st to 15thDay
43%8%19%19%8%
2396
16th to endDay
42%10%18%22%6%
2519
August1st to 15thDay
31%8%21%27%10%
2472
16th to endDay
44%10%17%18%6%1
2460
September1st to 15thDay
44%7%16%16%10%4
2145
16th to endDay
41%6%11%17%16%6%
2145
October1st to 15thDay
32%5%10%21%15%14%
2008
16th to endDay
32%2413%28%17%
2080
November1st to 15thDay
39%411%17%17%8%
2058
16th to endDay
38%35%14%23%14%
2028
December1st to 15thDay
50%37%15%15%7%
1755
16th to endDay
50%47%15%14%6%
1872
January1st to 15thNight
40%25%17%21%12%
2522
16th to endNight
41%35%14%20%14%
2704
February1st to 15thNight
44%36%13%18%13%
2367
16th to endNight
43%47%15%15%13%
1944
March1st to 15thNight
42%47%15%19%10%
2145
16th to endNight
36%413%15%21%8%
2288
April1st to 15thNight
38%411%16%16%11%
2110
16th to endNight
37%411%20%17%9%
1928
May1st to 15thNight
37%5%12%21%14%8%
1825
16th to endNight
28%6%17%29%14%3
1829
June1st to 15thNight
19%7%18%31%20%1
1755
16th to endNight
28%9%19%29%12%
1755
July1st to 15thNight
23%9%29%26%10%
1665
16th to endNight
21%11%29%31%6%
1738
August1st to 15thNight
14%429%38%11%
1717
16th to endNight
30%11%25%23%6%1
2089
September1st to 15thNight
35%8%21%18%10%4
2145
16th to endNight
31%6%15%21%16%7%
2145
October1st to 15thNight
23%412%29%16%13%
2268
16th to endNight
28%25%14%28%20%
2496
November1st to 15thNight
35%411%20%19%8%
2460
16th to endNight
34%36%17%23%15%
2583
December1st to 15thNight
46%38%17%15%8%
2535
16th to endNight
48%46%14%16%10%
2704

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
24%13%35%17%6%2
135
16th to endDay
24%15%38%15%5%
144
February1st to 15thDay
21%17%36%19%5%
135
16th to endDay
24%20%38%13%3
120
March1st to 15thDay
26%16%40%14%2
135
16th to endDay
14%13%40%22%8%
144
April1st to 15thDay
13%24%30%22%9%
167
16th to endDay
18%10%30%26%11%1
319
May1st to 15thDay
16%9%34%26%10%1
469
16th to endDay
10%6%27%34%17%3
597
June1st to 15thDay
6%111%42%29%9%
570
16th to endDay
10%111%35%27%13%
570
July1st to 15thDay
7%18%29%33%19%
550
16th to endDay
21327%45%18%
595
August1st to 15thDay
4326%46%18%
549
16th to endDay
12%1216%37%29%
372
September1st to 15thDay
12%17%24%38%15%
180
16th to endDay
7%110%27%36%16%
180
October1st to 15thDay
3217%30%35%10%
180
16th to endDay
22%9%18%26%18%5%
192
November1st to 15thDay
16%8%28%32%12%1
180
16th to endDay
14%15%32%26%6%5%
178
December1st to 15thDay
26%8%27%22%6%7%
135
16th to endDay
33%20%29%14%2
144
January1st to 15thNight
22%13%27%27%8%
975
16th to endNight
22%12%32%26%5%
1040
February1st to 15thNight
24%11%30%28%5%
839
16th to endNight
22%13%37%22%3
578
March1st to 15thNight
23%9%34%27%4
585
16th to endNight
15%10%37%28%8%
624
April1st to 15thNight
14%9%39%28%7%
584
16th to endNight
18%7%35%27%10%
579
May1st to 15thNight
14%6%36%32%9%
585
16th to endNight
7%328%37%20%2
611
June1st to 15thNight
4114%50%27%2
585
16th to endNight
4113%43%32%3
585
July1st to 15thNight
5%6%45%33%9%
555
16th to endNight
4442%43%6%
612
August1st to 15thNight
2149%38%6%
575
16th to endNight
6%435%46%6%
621
September1st to 15thNight
9%15%32%41%9%
585
16th to endNight
9%110%31%40%7%
582
October1st to 15thNight
6%214%38%31%5%
708
16th to endNight
13%5%24%30%23%2
832
November1st to 15thNight
13%6%28%32%18%1
820
16th to endNight
16%8%27%30%16%1
903
December1st to 15thNight
23%9%26%28%12%
975
16th to endNight
26%10%26%28%7%
1040
Page generated at 2018-12-01 10:35:34. Version ac04

Copyright 2018 A. Danko


Honea-Egypt Observatory Clear Sky Chart |Charts Home