Middleville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Middleville clear sky chart from 2005-11-05 to 2017-09-24.

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
28%
14703
14%
46934
8%
14674
36%
14674
17%
32979

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
13%
720
8%
2506
3%
716
21%
716
7%
2002
January16th to endNight
19%
768
13%
2615
7%
768
28%
768
11%
1954
February1st to 15thNight
15%
701
10%
2287
3%
701
24%
701
11%
1727
February16th to endNight
19%
631
15%
1963
6%
631
30%
631
13%
1425
March1st to 15thNight
20%
720
14%
2077
7%
720
27%
720
15%
1521
March16th to endNight
31%
768
21%
2049
9%
768
40%
768
22%
1390
April1st to 15thNight
22%
718
16%
1796
5%
718
27%
718
19%
1317
April16th to endNight
27%
652
18%
1732
8%
652
34%
652
22%
1214
May1st to 15thNight
33%
360
18%
1440
16%
360
44%
360
17%
937
May16th to endNight
34%
375
14%
1497
9%
374
48%
374
19%
915
June1st to 15thNight
34%
360
10%
1440
9%
360
43%
360
14%
945
June16th to endNight
40%
360
9%
1440
11%
360
47%
360
18%
926
July1st to 15thNight
51%
340
15%
1360
21%
340
56%
340
28%
738
July16th to endNight
54%
376
15%
1418
17%
354
60%
354
27%
803
August1st to 15thNight
50%
473
15%
1544
10%
471
56%
471
26%
951
August16th to endNight
51%
696
22%
1842
10%
696
56%
696
39%
1115
September1st to 15thNight
45%
720
17%
1800
7%
720
48%
720
31%
1211
September16th to endNight
47%
693
24%
1893
15%
693
52%
693
32%
1202
October1st to 15thNight
31%
660
18%
1980
11%
660
40%
660
20%
1357
October16th to endNight
22%
704
11%
2181
5%
704
31%
704
12%
1651
November1st to 15thNight
26%
700
18%
2346
13%
700
35%
700
16%
1630
November16th to endNight
19%
720
12%
2520
7%
720
27%
720
10%
1911
December1st to 15thNight
15%
720
7%
2520
2%
720
21%
720
9%
1984
December16th to endNight
12%
768
10%
2688
4%
768
19%
768
8%
2153

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
17%8%36%5%3445%6%32%
48006
Night
17%9%47%5%34446%33%
47104
Cloud CoverDay
15%8%36%5%34445%39%
48016
Night
15%8%36%5%24345%40%
47109
TransparencyDay
51%411%20%10%1
47694
Night
51%411%20%10%1
46934
SeeingDay
23%12%29%20%9%4
5483
Night
23%12%29%24%9%1
14706

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
19%15%6%8%7%3424422%
1432
16th to endDay
15%14%6%10%8%45%34422%
1608
February1st to 15thDay
14%12%6%11%9%35%43423%
1575
16th to endDay
17%13%48%7%45%245%26%
1509
March1st to 15thDay
17%12%48%8%45%33426%
1870
16th to endDay
14%9%46%5%2434441%
2175
April1st to 15thDay
21%11%45%5%2334433%
2152
16th to endDay
21%7%35%423345%36%
2238
May1st to 15thDay
19%9%37%433446%33%
2511
16th to endDay
16%6%35%6%345%5%7%35%
2618
June1st to 15thDay
21%6%36%5%2445%6%31%
2520
16th to endDay
17%5%26%6%36%5%5%7%32%
2520
July1st to 15thDay
12%5%25%5%35%5%6%9%37%
2520
16th to endDay
12%5%25%5%45%6%7%9%35%
2654
August1st to 15thDay
12%6%26%6%45%5%5%7%37%
2405
16th to endDay
12%5%25%5%35%5%6%8%39%
2347
September1st to 15thDay
16%425%42435%7%41%
2160
16th to endDay
14%5%245%24447%44%
1923
October1st to 15thDay
21%8%26%5%34445%33%
1650
16th to endDay
26%10%47%5%345%3424%
1691
November1st to 15thDay
15%8%36%6%35%447%34%
1512
16th to endDay
21%12%5%8%5%34345%24%
1440
December1st to 15thDay
22%15%6%8%6%44345%19%
1440
16th to endDay
24%16%5%7%435%345%20%
1536
January1st to 15thNight
18%13%6%10%8%34445%19%
2506
16th to endNight
14%13%6%9%7%35%445%25%
2615
February1st to 15thNight
13%14%5%12%6%34446%23%
2285
16th to endNight
15%12%47%6%3445%6%29%
1963
March1st to 15thNight
17%11%47%7%2334431%
2065
16th to endNight
14%7%46%5%24345%41%
2049
April1st to 15thNight
22%7%46%423345%35%
1796
16th to endNight
17%8%25%6%245%36%37%
1732
May1st to 15thNight
20%7%35%423446%37%
1440
16th to endNight
14%6%35%5%3445%8%39%
1495
June1st to 15thNight
18%7%35%4335%5%6%34%
1440
16th to endNight
14%5%26%5%25%5%5%7%37%
1440
July1st to 15thNight
9%334435%5%5%8%47%
1440
16th to endNight
9%224426%6%5%9%45%
1514
August1st to 15thNight
8%5%25%6%346%6%9%41%
1554
16th to endNight
9%42442435%7%51%
1842
September1st to 15thNight
14%6%15%424446%44%
1800
16th to endNight
15%5%24423245%49%
1893
October1st to 15thNight
21%7%26%42435%7%34%
1980
16th to endNight
24%10%47%5%33446%26%
2181
November1st to 15thNight
18%9%36%5%345%45%33%
2346
16th to endNight
22%11%47%6%24345%24%
2520
December1st to 15thNight
20%16%5%7%6%24345%21%
2520
16th to endNight
24%15%5%9%6%3433420%
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
19%14%6%8%6%3433424%
1432
16th to endDay
14%14%5%10%8%45%44424%
1608
February1st to 15thDay
14%12%5%11%8%35%34426%
1575
16th to endDay
17%14%48%7%4433428%
1509
March1st to 15thDay
14%10%36%5%3421442%
1881
16th to endDay
11%7%2442223454%
2174
April1st to 15thDay
20%9%3442333439%
2152
16th to endDay
18%7%3442344443%
2238
May1st to 15thDay
14%7%25%42333448%
2511
16th to endDay
11%5%24423445%49%
2618
June1st to 15thDay
19%6%25%424345%39%
2520
16th to endDay
15%425%5%35%446%40%
2520
July1st to 15thDay
12%5%25%5%35%5%7%9%37%
2520
16th to endDay
12%5%25%446%6%7%9%35%
2654
August1st to 15thDay
8%425%43435%5%51%
2405
16th to endDay
9%41442335%6%52%
2347
September1st to 15thDay
15%425%32345%7%44%
2160
16th to endDay
14%4235%24446%47%
1923
October1st to 15thDay
19%8%25%5%33445%36%
1650
16th to endDay
25%9%37%5%3443427%
1691
November1st to 15thDay
14%7%36%434436%41%
1512
16th to endDay
18%12%47%5%24345%31%
1440
December1st to 15thDay
20%14%5%8%5%35%34424%
1440
16th to endDay
22%15%5%6%434345%24%
1536
January1st to 15thNight
18%13%6%9%8%3444423%
2506
16th to endNight
13%12%6%9%7%3434429%
2615
February1st to 15thNight
12%13%5%11%6%3445%5%27%
2278
16th to endNight
14%12%37%5%34346%32%
1963
March1st to 15thNight
14%7%36%42322347%
2077
16th to endNight
12%6%3442323353%
2049
April1st to 15thNight
21%7%45%42333439%
1796
16th to endNight
15%7%25%5%23446%42%
1732
May1st to 15thNight
17%6%2431333448%
1440
16th to endNight
11%5%14423347%50%
1495
June1st to 15thNight
16%7%35%43445%6%39%
1440
16th to endNight
14%5%26%5%35%45%7%40%
1440
July1st to 15thNight
9%324426%5%5%7%47%
1440
16th to endNight
8%3235%26%6%5%9%45%
1514
August1st to 15thNight
6%4144235%5%7%51%
1554
16th to endNight
8%314313346%59%
1842
September1st to 15thNight
14%5%15%424446%46%
1800
16th to endNight
14%5%23323235%52%
1893
October1st to 15thNight
19%6%26%423346%38%
1980
16th to endNight
23%10%36%5%33346%30%
2181
November1st to 15thNight
14%8%25%42343445%
2346
16th to endNight
17%10%36%5%2333439%
2520
December1st to 15thNight
18%14%46%5%2335%430%
2520
16th to endNight
21%14%47%5%2333328%
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
65%39%13%7%1
1433
16th to endDay
65%39%12%8%
1608
February1st to 15thDay
64%310%16%4
1577
16th to endDay
61%210%13%11%
1509
March1st to 15thDay
62%211%14%7%1
1881
16th to endDay
46%38%19%15%5%
2175
April1st to 15thDay
54%46%18%14%2
2152
16th to endDay
49%37%20%16%3
2238
May1st to 15thDay
51%38%19%14%2
2511
16th to endDay
46%6%11%21%12%1
2622
June1st to 15thDay
52%5%9%21%10%
2520
16th to endDay
48%5%11%21%11%1
2520
July1st to 15thDay
39%5%13%29%12%
2371
16th to endDay
42%6%14%24%10%
2487
August1st to 15thDay
45%5%15%22%10%
2391
16th to endDay
39%5%15%27%11%
2347
September1st to 15thDay
40%5%12%28%11%
2160
16th to endDay
39%5%12%32%10%
1923
October1st to 15thDay
51%5%11%21%10%
1650
16th to endDay
63%49%15%5%
1691
November1st to 15thDay
49%415%20%9%
1512
16th to endDay
61%5%11%12%7%1
1440
December1st to 15thDay
68%411%12%2
1440
16th to endDay
66%5%10%11%6%
1536
January1st to 15thNight
66%5%9%13%5%
2506
16th to endNight
60%39%17%8%
2615
February1st to 15thNight
61%311%17%5%
2287
16th to endNight
55%310%19%10%
1963
March1st to 15thNight
56%310%20%8%
2077
16th to endNight
45%310%20%16%3
2049
April1st to 15thNight
52%36%20%15%1
1796
16th to endNight
47%47%19%18%2
1732
May1st to 15thNight
49%37%20%14%4
1440
16th to endNight
42%5%13%21%14%2
1497
June1st to 15thNight
49%5%11%21%11%1
1440
16th to endNight
44%7%11%22%14%
1440
July1st to 15thNight
32%5%13%30%16%1
1360
16th to endNight
33%7%15%27%15%
1418
August1st to 15thNight
37%7%16%24%13%
1544
16th to endNight
31%416%33%13%
1842
September1st to 15thNight
40%410%30%11%1
1800
16th to endNight
37%411%35%10%
1893
October1st to 15thNight
49%410%22%13%
1980
16th to endNight
58%412%16%6%
2181
November1st to 15thNight
51%412%17%11%1
2346
16th to endNight
61%410%17%4
2520
December1st to 15thNight
65%412%14%3
2520
16th to endNight
68%49%12%5%
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%26%18%16%6%
60
16th to endDay
43%11%31%9%21
76
February1st to 15thDay
35%21%35%7%
90
16th to endDay
31%22%29%13%3
168
March1st to 15thDay
28%15%30%21%4
270
16th to endDay
22%20%29%16%9%2
288
April1st to 15thDay
28%20%29%15%5%1
270
16th to endDay
26%17%25%15%9%5%
270
May1st to 15thDay
27%12%29%19%6%4
288
16th to endDay
22%12%36%15%10%1
331
June1st to 15thDay
25%10%29%23%8%1
315
16th to endDay
17%10%34%23%11%2
315
July1st to 15thDay
15%5%32%27%14%4
305
16th to endDay
14%6%32%27%13%5%
326
August1st to 15thDay
14%428%35%8%7%
313
16th to endDay
13%6%25%29%14%11%
332
September1st to 15thDay
17%8%26%20%14%13%
315
16th to endDay
17%6%28%18%17%11%
287
October1st to 15thDay
25%13%24%23%9%3
255
16th to endDay
31%15%30%17%4
259
November1st to 15thDay
21%13%28%24%10%1
166
16th to endDay
40%15%28%6%10%
60
December1st to 15thDay
31%15%36%8%8%
60
16th to endDay
46%21%28%3
64
January1st to 15thNight
28%18%32%16%4
720
16th to endNight
22%15%32%24%4
768
February1st to 15thNight
21%20%35%19%3
704
16th to endNight
23%19%33%18%5%
631
March1st to 15thNight
28%14%31%22%3
720
16th to endNight
20%16%27%24%9%1
768
April1st to 15thNight
28%14%29%21%4
718
16th to endNight
24%14%30%21%9%
652
May1st to 15thNight
24%9%26%28%10%1
360
16th to endNight
17%8%35%25%13%
375
June1st to 15thNight
20%11%26%32%8%
360
16th to endNight
17%430%32%13%
360
July1st to 15thNight
7%5%27%42%15%1
340
16th to endNight
8%228%44%13%1
376
August1st to 15thNight
12%326%35%20%1
473
16th to endNight
11%427%32%21%2
696
September1st to 15thNight
19%5%26%27%18%2
720
16th to endNight
18%7%23%23%23%3
693
October1st to 15thNight
25%10%25%24%13%1
660
16th to endNight
31%14%25%22%6%
704
November1st to 15thNight
25%12%29%20%10%1
700
16th to endNight
32%15%24%18%7%
720
December1st to 15thNight
31%16%31%17%2
720
16th to endNight
35%13%30%17%2
768
Page generated at 2017-09-25 09:02:24. Version ac04

Copyright 2017 A. Danko


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