Chillicothe
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chillicothe clear sky chart from 2005-11-05 to 2018-04-23.

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
41%
16820
22%
49580
13%
16773
49%
16773
30%
30502

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
29%
975
21%
2576
8%
970
39%
970
29%
1658
January16th to endNight
27%
1040
22%
2704
8%
1040
36%
1040
29%
1768
February1st to 15thNight
26%
954
14%
2483
5%
950
31%
950
22%
1785
February16th to endNight
26%
754
22%
2120
6%
754
38%
754
28%
1356
March1st to 15thNight
31%
585
22%
2145
12%
585
43%
585
25%
1250
March16th to endNight
28%
624
13%
2288
10%
624
36%
624
15%
1596
April1st to 15thNight
32%
584
20%
1963
13%
584
44%
584
26%
1183
April16th to endNight
33%
558
22%
1810
15%
558
46%
558
23%
1181
May1st to 15thNight
41%
539
19%
1619
13%
539
50%
539
25%
1059
May16th to endNight
47%
563
21%
1526
13%
561
53%
561
32%
962
June1st to 15thNight
61%
540
20%
1440
11%
540
65%
540
42%
829
June16th to endNight
60%
540
22%
1440
12%
540
64%
540
45%
829
July1st to 15thNight
69%
510
19%
1396
13%
510
71%
510
42%
808
July16th to endNight
73%
564
23%
1594
22%
531
75%
531
44%
834
August1st to 15thNight
76%
539
25%
1610
28%
536
78%
536
44%
843
August16th to endNight
72%
573
25%
1844
31%
573
74%
573
40%
981
September1st to 15thNight
64%
540
26%
1800
27%
540
68%
540
35%
992
September16th to endNight
59%
568
28%
1993
23%
568
68%
568
35%
1051
October1st to 15thNight
45%
720
26%
2160
18%
720
51%
720
35%
1234
October16th to endNight
38%
768
28%
2304
16%
768
48%
768
34%
1320
November1st to 15thNight
40%
792
27%
2393
14%
792
53%
792
33%
1361
November16th to endNight
30%
975
23%
2730
9%
975
42%
975
30%
1695
December1st to 15thNight
29%
975
17%
2730
7%
975
37%
975
24%
1851
December16th to endNight
25%
1040
18%
2912
6%
1040
34%
1040
20%
2076

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%7%35%42445%7%41%
49932
Night
12%6%24424446%47%
49769
TransparencyDay
41%5%13%24%13%1
49625
Night
37%412%26%16%2
49581
SeeingDay
15%7%25%28%17%5%
6609
Night
15%7%30%32%13%1
16822

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
11%9%37%5%44446%37%
1690
16th to endDay
13%10%5%8%5%3444436%
1872
February1st to 15thDay
14%9%46%5%2435%7%34%
1710
16th to endDay
14%10%47%423345%38%
1649
March1st to 15thDay
12%11%36%5%3345%6%36%
2145
16th to endDay
19%12%47%5%34345%28%
2286
April1st to 15thDay
18%9%35%424335%38%
2315
16th to endDay
22%8%36%434346%33%
2261
May1st to 15thDay
17%8%36%5%35%45%6%32%
2331
16th to endDay
13%5%35%5%3446%6%39%
2586
June1st to 15thDay
8%5%35%5%35%5%6%8%42%
2520
16th to endDay
7%3245%35%5%5%10%47%
2520
July1st to 15thDay
8%4245%25%5%6%9%45%
2478
16th to endDay
5%3235%35%5%7%10%48%
2466
August1st to 15thDay
7%4245%25%5%6%9%46%
2340
16th to endDay
8%5%25%5%2445%7%47%
2357
September1st to 15thDay
13%41432245%6%50%
2160
16th to endDay
8%424435%447%50%
1951
October1st to 15thDay
15%424424245%49%
1800
16th to endDay
13%5%1342335%6%50%
1920
November1st to 15thDay
12%5%2331345%6%50%
1791
16th to endDay
18%8%33323336%45%
1560
December1st to 15thDay
13%9%47%6%24436%36%
1560
16th to endDay
15%10%5%8%424345%35%
1664
January1st to 15thNight
9%6%25%5%3445%6%44%
2576
16th to endNight
9%8%46%424345%44%
2704
February1st to 15thNight
14%9%46%5%24445%37%
2473
16th to endNight
14%7%35%32335%6%45%
2120
March1st to 15thNight
15%6%24413345%47%
2145
16th to endNight
21%8%35%5%3445%6%31%
2288
April1st to 15thNight
12%6%245%24436%47%
1963
16th to endNight
15%10%35%423335%41%
1810
May1st to 15thNight
13%6%15%5%35%45%7%41%
1619
16th to endNight
11%4345%24447%48%
1524
June1st to 15thNight
5%31333447%10%50%
1440
16th to endNight
4313425%5%5%8%55%
1440
July1st to 15thNight
7%2134145%6%9%52%
1479
16th to endNight
33144245%5%10%54%
1702
August1st to 15thNight
311342446%10%55%
1620
16th to endNight
7%32332435%8%55%
1844
September1st to 15thNight
10%414423446%53%
1800
16th to endNight
7%3134235%6%6%55%
1993
October1st to 15thNight
14%413322346%53%
2160
16th to endNight
13%423322225%55%
2304
November1st to 15thNight
11%5%13323336%54%
2393
16th to endNight
16%6%23323246%48%
2730
December1st to 15thNight
15%7%35%5%34446%40%
2730
16th to endNight
17%10%47%5%23235%36%
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
47%312%21%14%1
1691
16th to endDay
50%314%20%9%
1872
February1st to 15thDay
49%417%20%7%1
1711
16th to endDay
47%313%20%14%
1649
March1st to 15thDay
46%5%12%24%9%1
2145
16th to endDay
58%410%19%6%
2288
April1st to 15thDay
47%411%24%11%
2315
16th to endDay
51%411%20%10%
2261
May1st to 15thDay
51%5%11%21%8%
2331
16th to endDay
43%6%15%23%10%1
2590
June1st to 15thDay
37%7%13%26%13%2
2520
16th to endDay
30%7%16%28%14%1
2520
July1st to 15thDay
34%7%15%26%12%2
2332
16th to endDay
28%7%15%31%15%
2311
August1st to 15thDay
32%6%16%27%16%
2326
16th to endDay
35%5%10%24%18%5%
2357
September1st to 15thDay
33%410%27%18%5%
2160
16th to endDay
32%5%11%33%15%2
1951
October1st to 15thDay
36%410%25%19%4
1800
16th to endDay
34%412%25%20%3
1920
November1st to 15thDay
34%313%25%20%3
1791
16th to endDay
42%211%28%15%
1560
December1st to 15thDay
49%414%20%10%
1560
16th to endDay
50%413%20%8%1
1664
January1st to 15thNight
38%412%27%15%1
2576
16th to endNight
40%316%24%13%1
2704
February1st to 15thNight
49%412%20%10%1
2483
16th to endNight
40%312%23%17%2
2120
March1st to 15thNight
39%312%27%15%2
2145
16th to endNight
53%411%20%7%1
2288
April1st to 15thNight
38%49%27%16%2
1963
16th to endNight
45%39%24%14%1
1810
May1st to 15thNight
41%6%13%23%14%1
1620
16th to endNight
35%7%14%25%15%1
1526
June1st to 15thNight
26%5%17%30%16%2
1440
16th to endNight
25%6%13%31%18%4
1440
July1st to 15thNight
26%6%13%31%17%4
1396
16th to endNight
24%415%35%17%2
1594
August1st to 15thNight
23%5%15%33%20%2
1610
16th to endNight
26%5%12%24%23%7%
1844
September1st to 15thNight
30%410%25%22%6%
1800
16th to endNight
27%5%11%33%18%3
1993
October1st to 15thNight
32%310%24%23%5%
2160
16th to endNight
33%29%27%23%4
2304
November1st to 15thNight
32%311%24%20%6%
2393
16th to endNight
38%210%28%18%1
2730
December1st to 15thNight
44%414%24%11%
2730
16th to endNight
51%311%19%11%2
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
25%11%36%22%5%
135
16th to endDay
18%11%45%20%4
144
February1st to 15thDay
19%20%39%14%6%
135
16th to endDay
22%21%36%9%9%
120
March1st to 15thDay
17%14%48%17%1
135
16th to endDay
38%13%33%11%3
144
April1st to 15thDay
23%11%33%22%7%1
314
16th to endDay
26%8%32%21%9%
334
May1st to 15thDay
20%9%32%24%10%2
468
16th to endDay
17%7%29%27%14%2
517
June1st to 15thDay
9%5%22%33%21%7%
495
16th to endDay
8%330%33%19%5%
495
July1st to 15thDay
11%214%38%25%8%
475
16th to endDay
411%38%36%8%
515
August1st to 15thDay
8%111%37%33%7%
493
16th to endDay
13%312%29%30%10%
397
September1st to 15thDay
12%313%33%28%8%
315
16th to endDay
6%423%40%14%11%
150
October1st to 15thDay
15%6%34%26%10%5%
135
16th to endDay
13%10%36%29%9%
144
November1st to 15thDay
12%431%30%10%11%
135
16th to endDay
31%12%28%22%4
135
December1st to 15thDay
9%24%39%15%7%3
135
16th to endDay
25%18%36%19%1
144
January1st to 15thNight
12%12%41%25%7%
975
16th to endNight
13%11%40%29%4
1040
February1st to 15thNight
18%10%37%28%4
955
16th to endNight
18%11%39%24%4
754
March1st to 15thNight
18%9%36%28%6%
585
16th to endNight
26%7%33%25%5%
624
April1st to 15thNight
16%9%37%28%6%
584
16th to endNight
22%8%31%30%7%
558
May1st to 15thNight
14%7%29%36%10%1
540
16th to endNight
14%426%36%15%2
563
June1st to 15thNight
7%322%42%20%2
540
16th to endNight
5%127%45%18%1
540
July1st to 15thNight
9%212%41%31%2
510
16th to endNight
5%12%43%35%2
564
August1st to 15thNight
49%47%35%2
539
16th to endNight
8%19%41%33%5%
573
September1st to 15thNight
11%215%38%26%5%
540
16th to endNight
9%320%37%25%4
568
October1st to 15thNight
16%430%29%16%2
720
16th to endNight
16%9%31%30%10%
768
November1st to 15thNight
13%9%32%33%10%
792
16th to endNight
18%9%38%24%8%
975
December1st to 15thNight
20%10%36%26%6%
975
16th to endNight
22%9%35%27%4
1040
Page generated at 2018-04-24 09:03:04. Version ac04

Copyright 2018 A. Danko


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