Meridian State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Meridian State Park clear sky chart from 2005-11-05 to 2017-09-19.

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
50%
15533
29%
46948
19%
15487
60%
15487
39%
25602

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
38%
897
29%
2327
12%
895
47%
895
39%
1381
January16th to endNight
34%
951
33%
2487
12%
951
47%
951
39%
1448
February1st to 15thNight
32%
704
29%
2105
13%
697
45%
697
33%
1212
February16th to endNight
25%
632
32%
1894
10%
632
42%
632
37%
1032
March1st to 15thNight
32%
552
27%
1992
15%
552
47%
552
27%
1124
March16th to endNight
33%
576
26%
2112
15%
576
49%
576
31%
1104
April1st to 15thNight
30%
539
26%
1977
12%
539
50%
539
33%
1005
April16th to endNight
33%
540
27%
1716
15%
540
51%
540
34%
976
May1st to 15thNight
36%
539
23%
1620
15%
539
50%
539
32%
955
May16th to endNight
48%
562
24%
1684
19%
561
59%
561
37%
968
June1st to 15thNight
70%
540
24%
1620
24%
540
75%
540
53%
782
June16th to endNight
73%
540
26%
1620
29%
540
76%
540
44%
864
July1st to 15thNight
80%
510
25%
1530
29%
510
82%
510
48%
787
July16th to endNight
87%
564
29%
1594
33%
531
89%
531
50%
794
August1st to 15thNight
91%
539
35%
1610
41%
536
91%
536
60%
734
August16th to endNight
78%
573
26%
1948
32%
573
78%
573
36%
1049
September1st to 15thNight
75%
540
23%
1980
27%
540
76%
540
34%
1033
September16th to endNight
73%
504
31%
1857
31%
504
77%
504
38%
929
October1st to 15thNight
64%
531
35%
1851
30%
531
71%
531
44%
878
October16th to endNight
53%
704
36%
2112
21%
704
63%
704
49%
1061
November1st to 15thNight
52%
736
31%
2136
17%
736
61%
736
43%
1154
November16th to endNight
43%
900
32%
2340
16%
900
52%
900
41%
1372
December1st to 15thNight
40%
900
31%
2340
15%
900
49%
900
39%
1401
December16th to endNight
38%
960
27%
2496
11%
960
47%
960
34%
1559

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
22%313323346%45%
47855
Night
22%312212346%49%
47151
Cloud CoverDay
9%42342445%7%52%
47853
Night
9%313323347%57%
47151
TransparencyDay
31%5%10%21%21%9%
47553
Night
27%410%21%22%12%
46956
SeeingDay
9%420%31%26%7%
5515
Night
10%6%28%35%17%1
15538

By Month

Percentage Cloud Cover SW (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
29%41321222445%
1611
16th to endDay
23%41221324449%
1746
February1st to 15thDay
25%5%1421322446%
1750
16th to endDay
27%412111235%48%
1580
March1st to 15thDay
32%41231322439%
1968
16th to endDay
24%32321224447%
2112
April1st to 15thDay
25%413322246%43%
1971
16th to endDay
26%41332233444%
2238
May1st to 15thDay
27%424323335%38%
2331
16th to endDay
26%5%1442445%7%33%
2430
June1st to 15thDay
19%212323447%45%
2340
16th to endDay
20%212323447%46%
2340
July1st to 15thDay
20%2332435%7%45%
2340
16th to endDay
21%22334348%45%
2466
August1st to 15thDay
11%1142345%8%55%
2340
16th to endDay
15%315%6%35%46%8%39%
2250
September1st to 15thDay
16%31443435%7%44%
1980
16th to endDay
16%313323346%49%
1848
October1st to 15thDay
17%413222336%52%
1767
16th to endDay
16%2221123461%
1760
November1st to 15thDay
23%41332223448%
1719
16th to endDay
27%31331112449%
1620
December1st to 15thDay
31%6%1411223440%
1620
16th to endDay
27%7%1321233440%
1728
January1st to 15thNight
28%41221223347%
2327
16th to endNight
25%3122223451%
2487
February1st to 15thNight
26%41421113447%
2102
16th to endNight
25%312212235%50%
1894
March1st to 15thNight
29%412323335%40%
1992
16th to endNight
22%312212335%51%
2112
April1st to 15thNight
21%313212336%48%
1977
16th to endNight
24%313221335%46%
1716
May1st to 15thNight
24%313312247%44%
1619
16th to endNight
22%31132245%10%42%
1683
June1st to 15thNight
18%12222347%54%
1620
16th to endNight
18%12222247%55%
1620
July1st to 15thNight
19%1221335%8%52%
1620
16th to endNight
19%12212349%51%
1702
August1st to 15thNight
11%1212248%63%
1620
16th to endNight
14%31432445%9%46%
1948
September1st to 15thNight
16%31322235%7%49%
1980
16th to endNight
15%213323447%51%
1857
October1st to 15thNight
16%32212245%59%
1851
16th to endNight
15%21221122362%
2112
November1st to 15thNight
20%312313235%52%
2136
16th to endNight
26%31322223446%
2340
December1st to 15thNight
28%5%13212235%42%
2340
16th to endNight
26%5%2331333442%
2496

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%5%2321332454%
1611
16th to endDay
11%422224345%56%
1746
February1st to 15thDay
11%5%24323225%55%
1750
16th to endDay
15%5%23212245%55%
1580
March1st to 15thDay
16%5%23423335%49%
1968
16th to endDay
12%5%34313245%51%
2110
April1st to 15thDay
10%41433435%7%50%
1971
16th to endDay
11%5%24424445%50%
2238
May1st to 15thDay
12%5%35%425%447%44%
2331
16th to endDay
10%6%25%5%25%5%6%10%39%
2430
June1st to 15thDay
421443445%9%55%
2340
16th to endDay
7%3145%245%6%7%50%
2340
July1st to 15thDay
6%324426%45%10%48%
2340
16th to endDay
5%213436%45%9%51%
2466
August1st to 15thDay
3124345%7%9%59%
2340
16th to endDay
7%415%6%35%5%6%9%44%
2250
September1st to 15thDay
9%4135%35%5%6%7%47%
1980
16th to endDay
7%42332445%7%54%
1848
October1st to 15thDay
9%41322335%6%57%
1767
16th to endDay
8%212212235%67%
1760
November1st to 15thDay
9%423423345%56%
1719
16th to endDay
12%31331222461%
1620
December1st to 15thDay
14%7%14212345%51%
1620
16th to endDay
13%8%24323345%49%
1728
January1st to 15thNight
13%5%2221223458%
2327
16th to endNight
12%412213245%58%
2487
February1st to 15thNight
12%42431223457%
2102
16th to endNight
13%323212345%58%
1894
March1st to 15thNight
14%423324446%49%
1992
16th to endNight
8%423323347%56%
2112
April1st to 15thNight
6%41442335%8%55%
1977
16th to endNight
9%425%322446%53%
1716
May1st to 15thNight
10%32343335%9%49%
1619
16th to endNight
7%3123245%6%11%49%
1683
June1st to 15thNight
211222335%9%65%
1620
16th to endNight
422332435%8%59%
1620
July1st to 15thNight
411321346%11%58%
1620
16th to endNight
2123235%6%11%61%
1702
August1st to 15thNight
11121335%9%68%
1620
16th to endNight
6%31443446%9%51%
1948
September1st to 15thNight
9%41332336%8%53%
1980
16th to endNight
7%31332345%7%57%
1857
October1st to 15thNight
8%312212346%63%
1851
16th to endNight
8%31221232467%
2112
November1st to 15thNight
7%313323336%61%
2136
16th to endNight
10%313323335%58%
2340
December1st to 15thNight
12%5%24212346%54%
2340
16th to endNight
12%6%23413335%52%
2496

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
34%35%17%26%12%
1612
16th to endDay
29%46%17%26%15%
1746
February1st to 15thDay
33%35%17%24%15%
1751
16th to endDay
32%36%18%24%15%
1580
March1st to 15thDay
38%47%14%23%10%
1968
16th to endDay
34%49%18%22%9%
2112
April1st to 15thDay
32%6%9%20%17%13%
1971
16th to endDay
36%47%18%23%10%
2238
May1st to 15thDay
40%5%9%17%18%8%
2331
16th to endDay
38%8%11%19%17%2
2434
June1st to 15thDay
24%7%12%26%22%5%
2340
16th to endDay
30%7%13%24%19%5%
2340
July1st to 15thDay
30%7%16%27%16%2
2201
16th to endDay
25%7%18%28%17%1
2311
August1st to 15thDay
19%7%14%32%22%3
2326
16th to endDay
34%7%15%25%15%2
2250
September1st to 15thDay
33%7%11%22%18%7%
1980
16th to endDay
28%5%11%21%23%9%
1848
October1st to 15thDay
27%5%10%21%20%15%
1767
16th to endDay
20%36%16%31%20%
1760
November1st to 15thDay
29%48%24%21%11%
1719
16th to endDay
29%3317%26%19%
1620
December1st to 15thDay
35%47%21%22%8%
1620
16th to endDay
37%37%18%23%8%
1728
January1st to 15thNight
30%26%17%25%17%
2327
16th to endNight
29%25%16%26%18%
2487
February1st to 15thNight
32%35%13%25%19%
2112
16th to endNight
29%27%19%22%18%
1894
March1st to 15thNight
34%410%13%22%13%
1992
16th to endNight
28%6%11%21%25%8%
2112
April1st to 15thNight
27%410%20%20%15%
1977
16th to endNight
30%5%11%17%24%11%
1716
May1st to 15thNight
31%6%11%19%20%9%
1620
16th to endNight
26%9%17%22%20%4
1685
June1st to 15thNight
16%5%14%31%24%7%
1620
16th to endNight
22%6%12%28%24%5%
1620
July1st to 15thNight
18%7%16%35%18%3
1530
16th to endNight
15%8%19%33%19%2
1594
August1st to 15thNight
13%415%35%25%5%
1610
16th to endNight
27%6%16%27%16%4
1948
September1st to 15thNight
27%6%13%25%18%8%
1980
16th to endNight
25%5%9%23%22%13%
1857
October1st to 15thNight
21%411%24%19%18%
1851
16th to endNight
21%35%17%27%25%
2112
November1st to 15thNight
25%47%23%24%14%
2136
16th to endNight
29%37%14%26%19%
2340
December1st to 15thNight
31%29%21%21%12%
2340
16th to endNight
35%37%17%22%12%
2496

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
20%10%31%30%7%1
90
16th to endDay
11%12%42%25%7%1
96
February1st to 15thDay
7%14%37%36%3
90
16th to endDay
17%11%46%19%4
81
March1st to 15thDay
25%12%32%22%7%
90
16th to endDay
9%8%42%27%11%1
96
April1st to 15thDay
13%16%26%34%8%
90
16th to endDay
13%11%42%23%8%
348
May1st to 15thDay
14%10%37%27%8%2
468
16th to endDay
15%6%32%28%15%3
517
June1st to 15thDay
4115%45%27%5%
495
16th to endDay
5%214%36%30%10%
495
July1st to 15thDay
49%39%38%8%
475
16th to endDay
31428%43%18%
515
August1st to 15thDay
4230%46%16%
493
16th to endDay
12%9%33%30%13%
290
September1st to 15thDay
222%51%23%
135
16th to endDay
5%313%54%24%
99
October1st to 15thDay
18%37%44%7%
90
16th to endDay
18%315%28%29%5%
96
November1st to 15thDay
23%6%27%26%12%3
90
16th to endDay
23%17%24%23%10%1
90
December1st to 15thDay
24%7%26%23%13%4
90
16th to endDay
16%13%37%26%6%
96
January1st to 15thNight
16%10%32%32%9%
900
16th to endNight
15%10%37%31%6%
951
February1st to 15thNight
16%11%36%30%5%
704
16th to endNight
15%12%45%24%2
632
March1st to 15thNight
16%10%38%28%5%
552
16th to endNight
9%11%43%30%5%
576
April1st to 15thNight
7%10%49%28%4
539
16th to endNight
9%8%45%27%8%
540
May1st to 15thNight
11%9%39%32%7%1
540
16th to endNight
7%237%34%15%1
563
June1st to 15thNight
222%50%21%2
540
16th to endNight
2115%49%27%3
540
July1st to 15thNight
49%50%32%2
510
16th to endNight
3445%41%4
564
August1st to 15thNight
2343%44%6%
539
16th to endNight
8%438%41%5%
573
September1st to 15thNight
9%16%41%36%3
540
16th to endNight
8%10%38%38%4
504
October1st to 15thNight
9%120%41%22%4
531
16th to endNight
9%5%29%33%20%1
704
November1st to 15thNight
7%432%36%17%1
736
16th to endNight
12%8%32%32%12%1
900
December1st to 15thNight
16%7%33%33%9%
900
16th to endNight
16%9%32%32%8%
960
Page generated at 2017-09-20 03:49:50. Version ac04

Copyright 2017 A. Danko


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