Beckwith Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Beckwith Park clear sky chart from 2005-11-05 to 2018-02-22.

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%
15306
14%
48936
8%
15276
35%
15276
16%
34808

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
14%
780
8%
2716
2%
776
21%
776
7%
2157
January16th to endNight
18%
832
11%
2844
6%
832
26%
832
10%
2151
February1st to 15thNight
15%
762
11%
2482
3%
761
25%
761
10%
1907
February16th to endNight
19%
659
14%
2043
6%
659
30%
659
13%
1530
March1st to 15thNight
19%
720
14%
2088
6%
720
27%
720
15%
1546
March16th to endNight
29%
768
20%
2042
9%
768
37%
768
21%
1418
April1st to 15thNight
22%
718
16%
1796
6%
718
27%
718
18%
1327
April16th to endNight
27%
653
18%
1733
7%
653
33%
653
21%
1220
May1st to 15thNight
32%
360
18%
1440
15%
360
43%
360
16%
946
May16th to endNight
32%
375
14%
1497
9%
374
45%
374
19%
931
June1st to 15thNight
33%
360
10%
1440
8%
360
42%
360
14%
967
June16th to endNight
38%
360
9%
1440
10%
360
45%
360
18%
922
July1st to 15thNight
50%
340
15%
1360
21%
340
56%
340
27%
759
July16th to endNight
56%
376
14%
1418
16%
354
61%
354
27%
811
August1st to 15thNight
48%
461
15%
1532
10%
459
54%
459
25%
966
August16th to endNight
51%
705
21%
1851
10%
705
56%
705
37%
1128
September1st to 15thNight
43%
720
16%
1800
7%
720
47%
720
31%
1230
September16th to endNight
49%
717
24%
1960
15%
717
54%
717
31%
1236
October1st to 15thNight
33%
720
17%
2160
11%
720
40%
720
21%
1476
October16th to endNight
23%
768
12%
2388
5%
768
33%
768
13%
1794
November1st to 15thNight
26%
760
17%
2534
12%
760
35%
760
16%
1780
November16th to endNight
19%
780
11%
2730
6%
780
27%
780
10%
2097
December1st to 15thNight
16%
780
7%
2730
3%
780
21%
780
7%
2184
December16th to endNight
12%
832
10%
2912
4%
832
20%
832
7%
2325

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%9%36%6%34446%32%
49322
Night
17%10%36%5%24446%33%
49105
Cloud CoverDay
19%8%36%5%34446%33%
49331
Night
18%9%36%5%24445%34%
49111
TransparencyDay
51%6%11%19%10%1
49009
Night
52%5%11%19%10%1
48936
SeeingDay
23%13%29%20%9%3
5907
Night
23%12%29%23%9%
15308

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%14%6%10%7%45%33321%
1552
16th to endDay
13%15%5%10%8%35%445%21%
1730
February1st to 15thDay
14%14%5%11%8%35%435%23%
1710
16th to endDay
19%13%47%6%34345%25%
1577
March1st to 15thDay
18%11%49%7%45%34427%
1859
16th to endDay
15%9%36%5%3234440%
2181
April1st to 15thDay
22%10%36%423435%33%
2152
16th to endDay
21%7%25%5%24336%37%
2235
May1st to 15thDay
19%8%36%5%2445%6%33%
2511
16th to endDay
16%6%36%5%25%45%7%36%
2618
June1st to 15thDay
21%7%35%5%25%5%47%31%
2520
16th to endDay
16%6%35%6%35%5%6%8%31%
2520
July1st to 15thDay
12%5%245%35%5%7%8%38%
2520
16th to endDay
11%5%25%5%35%5%7%9%37%
2654
August1st to 15thDay
11%7%35%6%445%5%7%37%
2418
16th to endDay
12%5%25%5%445%5%8%40%
2339
September1st to 15thDay
16%5%145%3345%7%41%
2160
16th to endDay
14%424433447%45%
1996
October1st to 15thDay
21%8%25%5%3445%6%33%
1800
16th to endDay
25%10%37%7%24435%25%
1835
November1st to 15thDay
16%8%37%6%26%5%46%32%
1651
16th to endDay
20%13%48%6%34445%24%
1560
December1st to 15thDay
22%15%5%8%6%44445%19%
1560
16th to endDay
23%13%5%7%6%35%44421%
1664
January1st to 15thNight
18%14%5%10%8%44335%20%
2716
16th to endNight
14%15%6%8%7%3445%5%25%
2844
February1st to 15thNight
13%15%5%10%7%34445%24%
2480
16th to endNight
16%12%48%7%25%346%28%
2043
March1st to 15thNight
18%11%48%5%34335%30%
2075
16th to endNight
15%8%46%5%2434441%
2042
April1st to 15thNight
21%9%35%5%23245%34%
1796
16th to endNight
17%8%26%5%24336%37%
1733
May1st to 15thNight
21%7%35%5%23445%36%
1440
16th to endNight
15%6%25%425%5%5%7%38%
1495
June1st to 15thNight
19%7%35%6%2445%7%33%
1440
16th to endNight
15%6%25%5%35%5%5%7%37%
1440
July1st to 15thNight
10%325%5%2446%7%47%
1440
16th to endNight
9%4234345%6%9%46%
1514
August1st to 15thNight
9%6%25%5%25%5%6%8%42%
1542
16th to endNight
9%42342445%7%51%
1851
September1st to 15thNight
15%5%25%5%23445%44%
1800
16th to endNight
15%423323436%49%
1960
October1st to 15thNight
19%7%35%423347%36%
2160
16th to endNight
25%9%36%5%3335%5%28%
2388
November1st to 15thNight
20%10%35%424445%33%
2534
16th to endNight
21%12%47%6%34345%25%
2730
December1st to 15thNight
20%16%5%8%6%2444421%
2730
16th to endNight
23%15%5%8%7%3433321%
2912

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%10%7%45%33321%
1552
16th to endDay
13%16%5%9%8%45%345%22%
1730
February1st to 15thDay
15%13%5%12%7%4444423%
1710
16th to endDay
20%12%5%7%7%35%34425%
1577
March1st to 15thDay
22%9%47%7%3423329%
1869
16th to endDay
19%9%25%42333441%
2180
April1st to 15thDay
22%11%35%42343434%
2152
16th to endDay
21%7%35%423336%37%
2235
May1st to 15thDay
24%8%26%423445%33%
2511
16th to endDay
22%6%25%425%446%35%
2618
June1st to 15thDay
21%6%345%24446%34%
2520
16th to endDay
16%6%25%5%345%5%7%36%
2520
July1st to 15thDay
13%4245%35%5%7%8%38%
2520
16th to endDay
12%5%25%5%36%5%6%9%36%
2654
August1st to 15thDay
18%5%246%34446%38%
2418
16th to endDay
17%425%424447%41%
2339
September1st to 15thDay
17%4245%33447%42%
2160
16th to endDay
14%5%24433446%46%
1996
October1st to 15thDay
21%8%25%424446%33%
1800
16th to endDay
25%10%38%6%2343425%
1835
November1st to 15thDay
17%8%36%6%35%446%34%
1651
16th to endDay
21%11%5%7%6%24345%26%
1560
December1st to 15thDay
22%15%49%6%3445%418%
1560
16th to endDay
24%14%5%7%5%3434322%
1664
January1st to 15thNight
19%14%5%10%8%34335%20%
2716
16th to endNight
14%15%5%9%7%3445%6%25%
2844
February1st to 15thNight
15%14%5%10%7%3444424%
2473
16th to endNight
17%11%48%6%34345%28%
2043
March1st to 15thNight
23%9%37%5%2333432%
2088
16th to endNight
18%7%45%42323442%
2042
April1st to 15thNight
21%9%35%5%23325%35%
1796
16th to endNight
19%7%26%424436%38%
1733
May1st to 15thNight
24%6%24413346%36%
1440
16th to endNight
18%6%245%24447%39%
1495
June1st to 15thNight
18%7%35%5%2435%6%35%
1440
16th to endNight
16%5%25%5%245%5%7%39%
1440
July1st to 15thNight
10%325%42445%8%47%
1440
16th to endNight
9%414335%5%6%10%45%
1514
August1st to 15thNight
14%425%5%345%5%7%42%
1542
16th to endNight
13%323323446%51%
1851
September1st to 15thNight
16%5%25%5%23345%45%
1800
16th to endNight
15%423323436%49%
1960
October1st to 15thNight
19%8%25%424347%37%
2160
16th to endNight
26%9%36%5%3345%5%28%
2388
November1st to 15thNight
20%9%35%324345%37%
2534
16th to endNight
21%11%46%6%34345%29%
2730
December1st to 15thNight
21%15%5%8%7%2443421%
2730
16th to endNight
24%15%5%7%7%3433320%
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
68%38%11%6%1
1553
16th to endDay
63%410%11%7%
1730
February1st to 15thDay
63%5%8%16%4
1712
16th to endDay
60%5%10%13%9%1
1577
March1st to 15thDay
61%410%14%7%
1869
16th to endDay
46%39%19%14%5%
2181
April1st to 15thDay
54%37%18%14%2
2152
16th to endDay
49%47%19%16%3
2235
May1st to 15thDay
50%5%9%18%14%2
2511
16th to endDay
46%6%11%21%11%1
2622
June1st to 15thDay
52%6%10%20%9%
2520
16th to endDay
48%8%11%19%11%
2520
July1st to 15thDay
37%7%13%28%12%
2371
16th to endDay
43%9%14%23%9%
2487
August1st to 15thDay
45%8%13%21%10%
2404
16th to endDay
38%6%15%27%11%
2339
September1st to 15thDay
41%6%11%28%11%
2160
16th to endDay
38%6%11%32%10%
1996
October1st to 15thDay
51%5%12%21%9%
1800
16th to endDay
60%5%11%15%5%
1835
November1st to 15thDay
51%6%13%18%8%
1651
16th to endDay
61%6%11%13%6%1
1560
December1st to 15thDay
67%6%10%11%3
1560
16th to endDay
65%6%10%11%5%
1664
January1st to 15thNight
66%49%12%5%
2716
16th to endNight
60%5%9%16%8%
2844
February1st to 15thNight
62%411%16%5%
2482
16th to endNight
57%49%18%9%
2043
March1st to 15thNight
56%410%19%8%
2088
16th to endNight
47%49%19%15%3
2042
April1st to 15thNight
53%36%19%15%1
1796
16th to endNight
47%5%6%19%18%3
1733
May1st to 15thNight
49%5%6%19%14%4
1440
16th to endNight
43%6%12%20%15%2
1497
June1st to 15thNight
50%6%11%20%10%1
1440
16th to endNight
43%7%12%20%14%
1440
July1st to 15thNight
33%6%13%29%15%1
1360
16th to endNight
33%7%16%25%16%
1418
August1st to 15thNight
37%9%15%23%13%
1532
16th to endNight
31%6%16%32%12%
1851
September1st to 15thNight
41%5%10%30%11%1
1800
16th to endNight
36%5%11%33%11%
1960
October1st to 15thNight
47%5%10%23%13%
2160
16th to endNight
57%5%13%17%6%
2388
November1st to 15thNight
52%5%13%17%10%1
2534
16th to endNight
61%5%10%16%4
2730
December1st to 15thNight
65%6%11%12%4
2730
16th to endNight
67%49%12%5%
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
26%24%25%17%5%
90
16th to endDay
34%19%34%8%1
112
February1st to 15thDay
31%28%31%8%
135
16th to endDay
34%22%27%12%3
198
March1st to 15thDay
26%16%29%22%4
270
16th to endDay
22%19%30%15%8%2
288
April1st to 15thDay
28%20%28%14%6%1
270
16th to endDay
27%17%23%18%6%5%
270
May1st to 15thDay
30%12%27%18%5%4
288
16th to endDay
21%16%33%18%9%1
331
June1st to 15thDay
28%11%29%20%8%1
315
16th to endDay
20%10%33%22%11%1
315
July1st to 15thDay
16%433%27%14%4
305
16th to endDay
13%5%32%27%15%4
326
August1st to 15thDay
15%6%29%31%11%7%
313
16th to endDay
11%6%28%28%14%11%
332
September1st to 15thDay
19%8%24%20%16%11%
315
16th to endDay
14%9%28%17%20%10%
314
October1st to 15thDay
25%12%26%21%10%3
315
16th to endDay
31%15%28%18%5%
314
November1st to 15thDay
23%16%26%22%8%1
215
16th to endDay
33%21%30%12%3
90
December1st to 15thDay
25%25%31%13%4
90
16th to endDay
37%28%27%7%
96
January1st to 15thNight
28%19%30%16%4
780
16th to endNight
23%15%34%21%4
832
February1st to 15thNight
22%20%35%18%3
764
16th to endNight
23%16%36%17%5%
659
March1st to 15thNight
27%14%32%22%2
720
16th to endNight
20%16%27%24%8%1
768
April1st to 15thNight
27%15%29%22%4
718
16th to endNight
24%14%30%20%8%
653
May1st to 15thNight
25%7%28%27%8%1
360
16th to endNight
19%5%37%25%11%
375
June1st to 15thNight
25%7%26%32%8%
360
16th to endNight
18%5%31%30%13%
360
July1st to 15thNight
10%5%27%41%13%1
340
16th to endNight
9%129%42%16%1
376
August1st to 15thNight
12%426%33%21%1
461
16th to endNight
11%427%32%22%1
705
September1st to 15thNight
20%327%26%18%2
720
16th to endNight
18%8%21%24%24%2
717
October1st to 15thNight
23%10%26%24%13%1
720
16th to endNight
29%15%25%23%6%
768
November1st to 15thNight
29%9%29%20%10%
760
16th to endNight
31%16%25%18%7%
780
December1st to 15thNight
30%18%29%18%2
780
16th to endNight
33%15%30%17%2
832
Page generated at 2018-02-23 11:21:32. Version ac04

Copyright 2018 A. Danko


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