Munro Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Munro Park clear sky chart from 2005-11-05 to 2017-12-04.

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
27%
15248
11%
47687
7%
15217
32%
15217
14%
35545

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%
883
5%
2670
2%
880
16%
880
7%
2277
January16th to endNight
22%
768
10%
2535
6%
768
27%
768
10%
2016
February1st to 15thNight
16%
702
7%
2287
4%
701
20%
701
9%
1832
February16th to endNight
19%
631
9%
2051
5%
631
24%
631
9%
1625
March1st to 15thNight
18%
720
12%
1984
5%
720
24%
720
13%
1549
March16th to endNight
30%
768
18%
2112
9%
768
37%
768
22%
1471
April1st to 15thNight
23%
712
14%
1800
5%
712
28%
712
19%
1358
April16th to endNight
30%
540
17%
1620
8%
540
37%
540
20%
1129
May1st to 15thNight
33%
431
16%
1511
12%
431
41%
431
19%
992
May16th to endNight
33%
374
13%
1497
10%
374
44%
374
19%
927
June1st to 15thNight
36%
360
9%
1318
8%
360
42%
360
18%
894
June16th to endNight
40%
360
9%
1260
8%
360
46%
360
19%
837
July1st to 15thNight
46%
340
15%
1190
16%
340
50%
340
29%
684
July16th to endNight
48%
407
13%
1424
14%
383
52%
383
23%
878
August1st to 15thNight
46%
539
13%
1609
10%
536
49%
536
23%
1075
August16th to endNight
45%
603
17%
1749
9%
603
50%
603
27%
1130
September1st to 15thNight
41%
720
14%
1800
7%
720
44%
720
31%
1205
September16th to endNight
42%
717
19%
2007
12%
717
47%
717
28%
1313
October1st to 15thNight
28%
720
15%
2160
10%
720
35%
720
18%
1551
October16th to endNight
17%
768
9%
2313
5%
768
23%
768
9%
1898
November1st to 15thNight
21%
760
12%
2657
9%
760
28%
760
12%
1984
November16th to endNight
17%
780
7%
2730
4%
780
21%
780
7%
2261
December1st to 15thNight
12%
736
5%
2574
2%
736
17%
736
5%
2223
December16th to endNight
12%
909
6%
2829
3%
909
16%
909
6%
2436

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
19%10%47%5%34446%29%
48809
Night
17%12%48%6%34345%28%
47849
Cloud CoverDay
19%11%47%5%34446%29%
48819
Night
17%12%5%8%6%34345%28%
47854
TransparencyDay
56%5%10%18%9%
48489
Night
57%410%17%8%
47687
SeeingDay
24%13%28%21%9%3
6010
Night
24%12%29%23%9%1
15253

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
17%17%8%12%7%3334417%
1265
16th to endDay
12%16%5%13%8%45%435%19%
1686
February1st to 15thDay
9%19%7%12%9%35%43419%
1575
16th to endDay
15%17%6%11%8%3433322%
1422
March1st to 15thDay
16%14%5%8%5%4434427%
1964
16th to endDay
14%8%47%6%34345%36%
2112
April1st to 15thDay
22%12%45%42335%5%29%
2159
16th to endDay
21%9%46%323236%37%
2340
May1st to 15thDay
22%9%35%434446%30%
2439
16th to endDay
19%6%245%25%447%37%
2618
June1st to 15thDay
21%6%36%6%25%5%5%7%29%
2639
16th to endDay
19%6%35%6%35%46%7%32%
2700
July1st to 15thDay
15%5%245%35%5%6%6%39%
2700
16th to endDay
15%6%35%5%3446%9%35%
2645
August1st to 15thDay
18%6%25%6%25%5%5%7%33%
2340
16th to endDay
16%5%26%6%4445%9%34%
2440
September1st to 15thDay
19%8%4442335%7%35%
2160
16th to endDay
21%7%35%5%23345%37%
1951
October1st to 15thDay
20%12%36%6%23245%32%
1800
16th to endDay
31%16%45%6%2333419%
1908
November1st to 15thDay
21%15%48%5%23345%23%
1529
16th to endDay
24%18%9%9%6%3323415%
1560
December1st to 15thDay
19%21%7%13%6%35%43410%
1468
16th to endDay
19%22%9%11%6%3423412%
1389
January1st to 15thNight
18%17%7%12%9%4433415%
2670
16th to endNight
13%17%7%9%7%36%44420%
2535
February1st to 15thNight
12%16%8%11%9%45%44419%
2285
16th to endNight
15%16%7%10%7%45%33421%
2051
March1st to 15thNight
16%15%5%9%6%3433426%
1972
16th to endNight
13%11%46%5%23336%39%
2112
April1st to 15thNight
22%12%5%5%423345%31%
1800
16th to endNight
20%10%25%6%3334435%
1620
May1st to 15thNight
18%7%25%6%2345%7%35%
1511
16th to endNight
15%6%16%42346%7%39%
1495
June1st to 15thNight
16%6%45%6%35%5%45%35%
1318
16th to endNight
14%6%27%5%4446%9%35%
1260
July1st to 15thNight
13%42432446%8%45%
1260
16th to endNight
11%5%2443446%9%41%
1521
August1st to 15thNight
15%6%25%43445%5%40%
1620
16th to endNight
14%425%4335%6%7%42%
1749
September1st to 15thNight
18%424423336%45%
1800
16th to endNight
15%7%26%433346%43%
2007
October1st to 15thNight
20%10%26%5%33446%32%
2160
16th to endNight
27%16%37%5%3333321%
2313
November1st to 15thNight
20%14%47%5%34345%26%
2657
16th to endNight
24%15%6%10%7%2433418%
2730
December1st to 15thNight
19%21%9%11%6%2433214%
2574
16th to endNight
21%19%8%12%7%3333314%
2829

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
17%17%8%13%6%2434416%
1265
16th to endDay
12%17%6%12%9%45%435%18%
1686
February1st to 15thDay
9%19%7%13%9%35%435%18%
1575
16th to endDay
15%18%7%10%9%3433420%
1422
March1st to 15thDay
17%14%5%8%6%4434427%
1975
16th to endDay
14%9%5%7%6%33345%36%
2111
April1st to 15thDay
22%13%45%423345%29%
2159
16th to endDay
20%10%36%313336%37%
2340
May1st to 15thDay
22%9%35%5%2445%6%30%
2439
16th to endDay
19%6%25%5%34447%36%
2618
June1st to 15thDay
21%7%36%6%35%35%6%29%
2639
16th to endDay
20%6%25%6%35%45%7%31%
2700
July1st to 15thDay
17%4245%345%5%7%38%
2700
16th to endDay
16%6%35%5%245%6%9%34%
2645
August1st to 15thDay
18%6%25%6%346%5%6%33%
2340
16th to endDay
17%6%26%5%3445%9%33%
2440
September1st to 15thDay
20%8%25%423446%35%
2160
16th to endDay
21%7%36%423435%37%
1951
October1st to 15thDay
21%12%36%5%33245%32%
1800
16th to endDay
31%16%46%5%2233419%
1908
November1st to 15thDay
21%15%5%7%5%23346%22%
1529
16th to endDay
23%18%9%10%6%2223415%
1560
December1st to 15thDay
19%21%8%12%7%35%34310%
1468
16th to endDay
19%21%10%11%6%3332313%
1389
January1st to 15thNight
18%17%7%12%9%4433414%
2670
16th to endNight
13%16%7%10%8%45%445%19%
2535
February1st to 15thNight
12%15%9%11%9%35%445%19%
2278
16th to endNight
15%16%7%11%7%35%43420%
2051
March1st to 15thNight
17%15%5%9%6%3432426%
1984
16th to endNight
13%12%46%6%23335%38%
2112
April1st to 15thNight
21%12%45%42443432%
1800
16th to endNight
20%9%26%5%2334435%
1620
May1st to 15thNight
18%8%26%42445%8%34%
1511
16th to endNight
16%6%26%43345%8%38%
1495
June1st to 15thNight
16%7%36%435%5%5%6%35%
1318
16th to endNight
15%5%27%5%35%5%5%8%35%
1260
July1st to 15thNight
12%43432447%8%44%
1260
16th to endNight
13%434425%5%6%9%40%
1521
August1st to 15thNight
15%6%15%5%35%45%6%40%
1620
16th to endNight
13%5%15%5%2446%7%42%
1749
September1st to 15thNight
18%4245%13345%45%
1800
16th to endNight
17%6%25%423345%44%
2007
October1st to 15thNight
21%9%36%42335%5%32%
2160
16th to endNight
28%16%36%6%2333320%
2313
November1st to 15thNight
20%14%5%7%5%23345%26%
2657
16th to endNight
23%16%6%10%6%3333418%
2730
December1st to 15thNight
19%21%9%11%7%2432314%
2574
16th to endNight
20%19%8%12%7%3433314%
2829

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
71%38%10%5%
1266
16th to endDay
67%5%7%12%6%
1686
February1st to 15thDay
69%39%12%5%
1577
16th to endDay
67%27%13%8%
1422
March1st to 15thDay
60%311%15%7%
1975
16th to endDay
49%38%19%15%3
2112
April1st to 15thDay
56%48%17%11%1
2159
16th to endDay
50%37%21%14%2
2340
May1st to 15thDay
54%48%17%12%1
2439
16th to endDay
46%6%11%21%12%1
2622
June1st to 15thDay
52%6%10%20%9%
2639
16th to endDay
50%6%11%19%10%1
2700
July1st to 15thDay
41%7%11%27%11%1
2541
16th to endDay
46%7%10%23%11%
2479
August1st to 15thDay
48%7%12%21%9%
2327
16th to endDay
47%5%13%25%7%
2440
September1st to 15thDay
49%5%12%23%9%
2160
16th to endDay
49%412%27%6%
1951
October1st to 15thDay
55%5%11%18%9%
1800
16th to endDay
69%410%10%5%
1908
November1st to 15thDay
62%5%12%12%6%
1529
16th to endDay
74%38%9%3
1560
December1st to 15thDay
78%5%7%7%1
1468
16th to endDay
77%3410%2
1389
January1st to 15thNight
74%38%8%4
2670
16th to endNight
66%48%14%6%
2535
February1st to 15thNight
67%410%12%4
2287
16th to endNight
66%38%14%6%
2051
March1st to 15thNight
62%310%15%7%
1984
16th to endNight
48%48%20%15%2
2112
April1st to 15thNight
55%36%19%12%1
1800
16th to endNight
51%27%19%16%2
1620
May1st to 15thNight
48%310%20%15%1
1511
16th to endNight
43%5%12%22%13%2
1497
June1st to 15thNight
48%6%9%22%10%1
1318
16th to endNight
46%6%12%22%11%1
1260
July1st to 15thNight
33%6%14%29%13%2
1190
16th to endNight
40%6%15%26%11%
1424
August1st to 15thNight
43%7%16%22%10%
1609
16th to endNight
38%7%17%26%9%
1749
September1st to 15thNight
41%417%26%9%
1800
16th to endNight
42%414%31%7%
2007
October1st to 15thNight
52%5%11%20%10%
2160
16th to endNight
68%5%9%12%5%
2313
November1st to 15thNight
59%5%12%16%5%
2657
16th to endNight
70%410%9%3
2730
December1st to 15thNight
76%47%9%2
2574
16th to endNight
76%37%7%5%
2829

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%28%30%13%3
60
16th to endDay
33%12%26%19%6%1
89
February1st to 15thDay
32%20%35%12%
90
16th to endDay
33%27%28%9%1
81
March1st to 15thDay
23%20%34%16%4
265
16th to endDay
21%17%30%18%9%2
288
April1st to 15thDay
28%11%31%18%8%1
270
16th to endDay
28%15%26%15%9%4
270
May1st to 15thDay
33%11%19%20%11%3
288
16th to endDay
23%14%30%18%11%1
331
June1st to 15thDay
25%13%28%23%7%1
434
16th to endDay
21%11%34%22%8%2
495
July1st to 15thDay
15%12%30%28%10%2
475
16th to endDay
18%8%29%26%12%3
349
August1st to 15thDay
24%323%28%12%7%
313
16th to endDay
20%8%25%23%13%7%
332
September1st to 15thDay
21%7%24%23%13%9%
315
16th to endDay
23%7%25%25%12%5%
314
October1st to 15thDay
25%12%31%20%8%
315
16th to endDay
34%17%28%14%31
324
November1st to 15thDay
26%24%32%12%4
91
16th to endDay
37%15%38%7%
90
December1st to 15thDay
25%23%29%19%1
67
16th to endDay
31%29%32%6%
64
January1st to 15thNight
28%16%31%18%4
885
16th to endNight
23%12%32%22%7%1
768
February1st to 15thNight
19%18%34%21%5%
704
16th to endNight
23%15%34%22%4
631
March1st to 15thNight
26%20%27%20%4
720
16th to endNight
18%14%29%25%9%1
768
April1st to 15thNight
28%15%29%20%5%
712
16th to endNight
25%13%27%22%10%
540
May1st to 15thNight
24%6%31%26%10%1
431
16th to endNight
18%10%33%27%10%
375
June1st to 15thNight
17%8%29%32%12%
360
16th to endNight
15%6%30%34%12%
360
July1st to 15thNight
14%230%37%14%
340
16th to endNight
14%426%36%17%
407
August1st to 15thNight
19%223%32%18%3
539
16th to endNight
16%5%27%29%18%2
603
September1st to 15thNight
20%428%24%17%3
720
16th to endNight
18%7%26%27%18%2
717
October1st to 15thNight
25%10%30%22%8%1
720
16th to endNight
37%13%25%17%4
768
November1st to 15thNight
27%14%29%18%8%
760
16th to endNight
32%15%27%18%5%
780
December1st to 15thNight
30%18%30%16%4
736
16th to endNight
31%15%29%19%31
909
Page generated at 2017-12-05 10:19:04. Version ac04

Copyright 2017 A. Danko


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