Firemen's Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Firemen's 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
31%
15180
12%
47879
8%
15142
36%
15142
14%
35093

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
10%
717
6%
2470
3%
716
14%
716
4%
2108
January16th to endNight
12%
768
6%
2496
2%
768
17%
768
4%
2163
February1st to 15thNight
13%
704
5%
2287
2%
701
18%
701
6%
1930
February16th to endNight
18%
631
7%
2006
3%
631
23%
631
8%
1648
March1st to 15thNight
20%
720
11%
1980
6%
720
25%
720
11%
1576
March16th to endNight
29%
768
19%
2112
9%
768
37%
768
18%
1513
April1st to 15thNight
24%
718
13%
1811
5%
718
28%
718
18%
1369
April16th to endNight
35%
587
20%
1667
7%
587
44%
587
23%
1126
May1st to 15thNight
37%
492
15%
1572
9%
492
45%
492
17%
1061
May16th to endNight
39%
374
17%
1497
13%
374
52%
374
17%
890
June1st to 15thNight
38%
360
13%
1440
11%
360
49%
360
16%
909
June16th to endNight
45%
360
12%
1440
13%
360
52%
360
18%
865
July1st to 15thNight
53%
340
17%
1360
22%
340
58%
340
27%
712
July16th to endNight
52%
492
15%
1525
15%
461
60%
461
27%
917
August1st to 15thNight
60%
539
15%
1609
13%
536
63%
536
27%
1003
August16th to endNight
59%
641
23%
1787
14%
641
63%
641
35%
1081
September1st to 15thNight
54%
720
20%
1800
11%
720
57%
720
31%
1204
September16th to endNight
54%
717
22%
2010
17%
717
56%
717
28%
1297
October1st to 15thNight
38%
720
16%
2160
15%
720
42%
720
19%
1512
October16th to endNight
22%
768
11%
2304
7%
768
28%
768
12%
1779
November1st to 15thNight
31%
760
16%
2554
15%
760
36%
760
16%
1781
November16th to endNight
19%
780
11%
2730
5%
780
26%
780
8%
2087
December1st to 15thNight
13%
736
4%
2574
2%
736
15%
736
5%
2200
December16th to endNight
9%
768
3%
2688
1%
768
12%
768
3%
2362

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
14%8%36%6%35%45%7%33%
48613
Night
16%9%47%5%3445%6%31%
48059
Cloud CoverDay
14%8%36%6%3445%7%33%
48623
Night
16%9%47%6%3445%6%31%
48063
TransparencyDay
49%7%12%19%10%
48312
Night
53%7%10%17%10%
47879
SeeingDay
17%14%21%23%16%7%
5640
Night
18%21%21%24%12%1
15184

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%16%6%10%9%345%5%5%14%
1467
16th to endDay
14%16%6%12%11%5%5%5%4413%
1728
February1st to 15thDay
16%17%6%11%8%46%45%5%15%
1575
16th to endDay
16%13%5%11%10%4435%5%18%
1465
March1st to 15thDay
16%11%5%10%8%35%445%23%
1969
16th to endDay
15%10%36%5%25%446%35%
2112
April1st to 15thDay
20%8%36%5%2425%6%32%
2136
16th to endDay
17%7%245%34346%40%
2304
May1st to 15thDay
15%6%26%5%3445%7%37%
2379
16th to endDay
10%5%25%435%47%8%41%
2618
June1st to 15thDay
13%6%25%5%2445%7%40%
2520
16th to endDay
12%4245%345%6%10%40%
2520
July1st to 15thDay
7%5%245%346%6%9%45%
2520
16th to endDay
10%425%5%45%5%7%9%37%
2535
August1st to 15thDay
8%415%435%5%7%10%41%
2340
16th to endDay
10%5%15%4345%5%9%44%
2402
September1st to 15thDay
14%6%24435%45%7%40%
2160
16th to endDay
12%6%344345%6%7%40%
1949
October1st to 15thDay
18%7%36%5%35%35%6%33%
1800
16th to endDay
24%10%38%5%245%45%25%
1920
November1st to 15thDay
12%10%47%6%35%5%47%31%
1630
16th to endDay
19%11%47%6%35%446%25%
1560
December1st to 15thDay
17%16%7%9%8%24346%18%
1468
16th to endDay
20%17%8%10%8%25%445%12%
1536
January1st to 15thNight
19%16%7%11%7%3433317%
2470
16th to endNight
15%15%7%11%8%45%44415%
2496
February1st to 15thNight
16%15%6%11%6%45%43420%
2285
16th to endNight
15%12%7%11%8%345%46%19%
2006
March1st to 15thNight
20%10%48%7%35%445%25%
1968
16th to endNight
16%8%47%42434438%
2112
April1st to 15thNight
20%9%35%6%3444432%
1811
16th to endNight
13%6%245%25%5%46%42%
1667
May1st to 15thNight
17%6%25%5%245%6%8%34%
1572
16th to endNight
11%5%25%5%25%5%6%7%42%
1495
June1st to 15thNight
12%6%25%5%35%6%5%7%38%
1440
16th to endNight
10%425%5%5%5%5%6%7%42%
1440
July1st to 15thNight
6%315%5%1445%8%52%
1440
16th to endNight
8%315%5%36%47%9%45%
1630
August1st to 15thNight
7%4145%45%5%7%7%46%
1620
16th to endNight
8%425%42446%7%51%
1787
September1st to 15thNight
15%5%2442345%6%45%
1800
16th to endNight
13%5%25%42335%7%46%
2010
October1st to 15thNight
20%6%35%5%23346%37%
2160
16th to endNight
24%9%27%4245%47%26%
2304
November1st to 15thNight
16%8%36%5%35%447%35%
2554
16th to endNight
20%11%5%7%5%35%446%25%
2730
December1st to 15thNight
22%16%6%9%6%3335%6%16%
2574
16th to endNight
20%15%8%10%7%35%45%5%13%
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
18%15%6%10%10%35%445%14%
1467
16th to endDay
14%16%5%12%11%5%5%44413%
1728
February1st to 15thDay
16%17%6%11%7%35%45%415%
1575
16th to endDay
17%14%5%11%9%4435%5%18%
1465
March1st to 15thDay
17%11%5%10%8%35%445%23%
1980
16th to endDay
16%9%36%5%24447%35%
2111
April1st to 15thDay
20%8%45%434346%33%
2136
16th to endDay
17%6%25%5%24346%40%
2304
May1st to 15thDay
15%6%26%5%245%5%7%37%
2379
16th to endDay
10%5%25%5%25%46%8%42%
2618
June1st to 15thDay
14%6%25%5%2445%7%40%
2520
16th to endDay
12%4235%345%6%10%41%
2520
July1st to 15thDay
7%5%245%35%5%7%8%45%
2520
16th to endDay
11%4345%35%5%7%9%37%
2535
August1st to 15thDay
8%4245%35%5%7%10%41%
2340
16th to endDay
10%425%4345%6%9%43%
2402
September1st to 15thDay
14%6%245%3445%7%40%
2160
16th to endDay
12%6%345%345%6%7%40%
1949
October1st to 15thDay
19%8%27%5%35%446%33%
1800
16th to endDay
24%11%38%6%245%4425%
1920
November1st to 15thDay
12%10%48%6%35%45%7%31%
1630
16th to endDay
20%12%47%6%35%445%25%
1560
December1st to 15thDay
18%17%7%9%7%33445%19%
1468
16th to endDay
20%18%8%10%7%35%44412%
1536
January1st to 15thNight
20%16%7%11%7%3433317%
2470
16th to endNight
15%16%7%11%9%45%44416%
2496
February1st to 15thNight
16%16%6%11%6%45%43419%
2278
16th to endNight
15%13%7%11%8%34346%19%
2006
March1st to 15thNight
20%10%5%8%7%45%345%24%
1980
16th to endNight
16%9%47%42444437%
2112
April1st to 15thNight
21%9%35%6%3444432%
1811
16th to endNight
13%6%245%25%5%46%42%
1667
May1st to 15thNight
16%6%35%5%345%6%8%34%
1571
16th to endNight
11%5%24435%45%8%43%
1495
June1st to 15thNight
12%6%346%35%5%5%8%37%
1440
16th to endNight
10%415%5%45%5%6%7%42%
1440
July1st to 15thNight
6%325%6%145%47%52%
1440
16th to endNight
8%3145%35%5%6%8%45%
1630
August1st to 15thNight
8%325%436%5%7%7%46%
1620
16th to endNight
8%42442346%7%51%
1787
September1st to 15thNight
15%42432435%6%45%
1800
16th to endNight
13%5%245%2435%7%45%
2010
October1st to 15thNight
20%6%35%5%23336%37%
2160
16th to endNight
24%9%36%5%345%5%6%26%
2304
November1st to 15thNight
16%8%36%5%35%347%35%
2554
16th to endNight
20%11%5%7%435%5%5%6%25%
2730
December1st to 15thNight
22%16%7%8%6%34345%16%
2574
16th to endNight
21%15%7%10%8%35%45%413%
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
70%8%8%10%2
1468
16th to endDay
75%7%8%6%1
1728
February1st to 15thDay
71%9%7%10%1
1577
16th to endDay
67%6%9%11%3
1465
March1st to 15thDay
62%6%11%14%4
1980
16th to endDay
49%7%10%22%9%1
2112
April1st to 15thDay
52%5%12%18%11%
2136
16th to endDay
45%410%20%16%2
2304
May1st to 15thDay
43%7%11%23%13%
2379
16th to endDay
37%7%14%24%13%1
2622
June1st to 15thDay
41%7%13%23%12%1
2520
16th to endDay
36%7%16%24%14%
2520
July1st to 15thDay
31%8%12%24%21%1
2371
16th to endDay
39%9%14%22%11%1
2378
August1st to 15thDay
33%10%17%22%14%1
2327
16th to endDay
34%7%12%30%13%1
2402
September1st to 15thDay
41%6%13%24%12%1
2160
16th to endDay
39%8%13%24%13%
1949
October1st to 15thDay
51%6%9%19%11%
1800
16th to endDay
60%7%14%12%4
1920
November1st to 15thDay
52%7%14%16%7%1
1630
16th to endDay
60%6%13%12%6%
1560
December1st to 15thDay
68%9%12%8%1
1468
16th to endDay
74%7%9%7%1
1536
January1st to 15thNight
72%6%8%8%3
2470
16th to endNight
72%8%9%7%2
2496
February1st to 15thNight
69%8%9%10%2
2287
16th to endNight
65%8%10%10%5%
2006
March1st to 15thNight
62%5%10%16%4
1980
16th to endNight
49%6%7%21%13%1
2112
April1st to 15thNight
55%49%18%12%
1811
16th to endNight
41%7%9%22%16%3
1667
May1st to 15thNight
45%6%10%21%13%1
1572
16th to endNight
38%7%12%24%15%2
1497
June1st to 15thNight
42%7%10%21%16%1
1440
16th to endNight
38%8%13%21%17%1
1440
July1st to 15thNight
30%5%11%25%22%3
1360
16th to endNight
33%8%14%22%16%3
1525
August1st to 15thNight
33%9%16%25%13%
1609
16th to endNight
30%6%11%32%16%1
1787
September1st to 15thNight
38%6%13%24%15%1
1800
16th to endNight
37%6%10%26%16%
2010
October1st to 15thNight
48%6%9%19%14%
2160
16th to endNight
57%8%12%14%6%
2304
November1st to 15thNight
49%7%12%18%11%
2554
16th to endNight
59%7%12%15%4
2730
December1st to 15thNight
70%9%11%6%2
2574
16th to endNight
75%8%9%6%1
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
21%21%31%12%10%3
66
16th to endDay
31%17%29%16%5%
96
February1st to 15thDay
21%22%41%14%1
90
16th to endDay
25%14%35%19%5%
108
March1st to 15thDay
23%21%25%21%7%
270
16th to endDay
22%18%25%25%5%3
288
April1st to 15thDay
21%20%26%22%7%2
270
16th to endDay
21%15%24%21%11%6%
270
May1st to 15thDay
21%13%20%22%16%5%
288
16th to endDay
13%14%27%23%15%5%
331
June1st to 15thDay
15%13%19%32%16%2
315
16th to endDay
16%13%21%24%20%3
315
July1st to 15thDay
10%10%13%28%25%12%
305
16th to endDay
12%11%17%26%21%9%
326
August1st to 15thDay
10%6%14%28%24%14%
313
16th to endDay
12%9%10%24%24%18%
332
September1st to 15thDay
10%7%15%23%26%16%
315
16th to endDay
13%9%15%17%24%19%
314
October1st to 15thDay
21%12%19%19%18%8%
315
16th to endDay
30%16%25%19%8%
336
November1st to 15thDay
17%15%23%29%9%3
156
16th to endDay
22%17%31%14%14%
90
December1st to 15thDay
16%25%31%17%8%
67
16th to endDay
23%31%35%9%
64
January1st to 15thNight
23%32%25%14%4
720
16th to endNight
21%27%27%18%4
768
February1st to 15thNight
19%29%27%19%3
704
16th to endNight
20%25%25%23%4
631
March1st to 15thNight
23%24%25%19%6%
720
16th to endNight
18%22%24%24%8%1
768
April1st to 15thNight
21%23%25%24%5%
718
16th to endNight
13%22%24%26%12%1
587
May1st to 15thNight
18%20%16%28%13%2
492
16th to endNight
12%20%21%29%16%
375
June1st to 15thNight
15%17%24%28%13%1
360
16th to endNight
10%19%17%38%12%
360
July1st to 15thNight
8%13%16%37%22%1
340
16th to endNight
8%17%15%37%19%1
492
August1st to 15thNight
10%11%10%34%27%5%
539
16th to endNight
9%9%14%31%29%4
641
September1st to 15thNight
13%11%14%29%25%5%
720
16th to endNight
14%11%14%25%24%9%
717
October1st to 15thNight
21%14%18%25%18%2
720
16th to endNight
29%17%25%21%5%
768
November1st to 15thNight
18%19%25%21%13%1
760
16th to endNight
24%27%23%16%7%
780
December1st to 15thNight
29%29%21%16%3
736
16th to endNight
24%29%27%14%3
768
Page generated at 2017-12-05 10:18:57. Version ac04

Copyright 2017 A. Danko


Firemen's Park Clear Sky Chart |Charts Home