Powersville
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Powersville clear sky chart from 2005-11-06 to 2024-01-12.

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
37%
24565
14%
74663
8%
24505
43%
24505
15%
56307

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 10thNight
25%
950
11%
2601
3%
946
31%
946
13%
2054
January11th to 20thNight
20%
906
11%
2354
3%
906
26%
906
11%
1952
January21st to endNight
21%
990
9%
2574
2%
990
26%
990
12%
2124
February1st to 10thNight
22%
900
10%
2340
3%
900
27%
900
13%
1902
February11th to 20thNight
24%
878
13%
2274
4%
875
30%
875
15%
1781
February21st to endNight
20%
625
14%
1809
4%
625
29%
625
14%
1403
March1st to 10thNight
26%
540
17%
1980
8%
540
36%
540
13%
1418
March11th to 20thNight
28%
540
12%
1980
7%
540
35%
540
10%
1515
March21st to endNight
20%
594
5%
2178
2%
594
24%
594
6%
1818
April1st to 10thNight
25%
540
12%
1806
6%
540
34%
540
14%
1297
April11th to 20thNight
26%
533
16%
1775
8%
533
37%
533
12%
1337
April21st to endNight
28%
540
15%
1724
7%
540
40%
540
13%
1308
May1st to 10thNight
36%
540
11%
1620
6%
540
43%
540
14%
1248
May11th to 20thNight
40%
531
15%
1494
10%
531
44%
531
15%
1154
May21st to endNight
48%
584
14%
1551
7%
582
53%
582
17%
1192
June1st to 10thNight
60%
540
12%
1440
7%
540
63%
540
20%
1055
June11th to 20thNight
56%
540
17%
1440
9%
540
59%
540
22%
1048
June21st to endNight
55%
540
16%
1440
8%
540
57%
540
22%
1047
July1st to 10thNight
72%
525
14%
1400
10%
525
72%
525
24%
993
July11th to 20thNight
67%
522
16%
1464
12%
522
70%
522
23%
1019
July21st to endNight
68%
591
15%
1673
15%
558
70%
558
20%
1196
August1st to 10thNight
68%
537
14%
1601
15%
534
70%
534
21%
1115
August11th to 20thNight
70%
534
20%
1600
21%
534
73%
534
22%
1104
August21st to endNight
72%
594
20%
1966
22%
594
76%
594
24%
1258
September1st to 10thNight
60%
540
20%
1800
19%
540
65%
540
20%
1207
September11th to 20thNight
58%
540
21%
1840
21%
540
62%
540
17%
1297
September21st to endNight
54%
598
18%
2038
14%
598
59%
598
20%
1366
October1st to 10thNight
45%
720
19%
2160
14%
720
48%
720
23%
1459
October11th to 20thNight
31%
720
14%
2160
6%
720
38%
720
15%
1623
October21st to endNight
29%
792
14%
2376
5%
792
37%
792
14%
1805
November1st to 10thNight
37%
740
17%
2294
8%
740
46%
740
18%
1601
November11th to 20thNight
27%
912
17%
2622
6%
912
37%
912
15%
1978
November21st to endNight
26%
950
12%
2660
5%
950
32%
950
13%
2075
December1st to 10thNight
25%
950
10%
2660
3%
950
32%
950
13%
2106
December11th to 20thNight
24%
949
14%
3135
4%
948
29%
948
10%
2352
December21st to endNight
19%
1040
6%
4834
3%
1026
26%
1026
5%
4100

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
13%8%36%5%3445%7%40%
74669
Night
12%7%36%5%3445%7%44%
75052
TransparencyDay
29%36%8%17%9%1
74381
Night
28%35%8%17%10%2
74860
SeeingDay
15%10%29%27%15%4
14595
Night
15%10%33%30%11%1
24572

By Month

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 10thDay
11%12%49%5%46%5%46%32%
1559
11th to 20thDay
13%12%6%10%7%46%345%29%
1629
21st to endDay
14%12%6%10%7%445%45%28%
1782
February1st to 10thDay
15%10%49%7%45%446%30%
1620
11th to 20thDay
13%10%48%7%445%5%6%34%
1574
21st to endDay
16%10%37%5%345%5%7%36%
1458
March1st to 10thDay
13%11%49%6%3435%5%37%
1980
11th to 20thDay
13%11%5%8%6%3445%7%35%
1980
21st to endDay
22%12%5%7%6%35%445%27%
2178
April1st to 10thDay
17%8%46%5%2445%7%38%
2153
11th to 20thDay
16%9%26%4345%6%6%38%
2134
21st to endDay
22%7%36%6%34446%36%
2232
May1st to 10thDay
17%8%37%5%35%46%8%33%
2340
11th to 20thDay
18%8%36%6%35%5%5%7%35%
2400
21st to endDay
15%7%47%6%35%5%5%7%36%
2725
June1st to 10thDay
8%426%5%35%6%8%9%44%
2520
11th to 20thDay
8%4245%45%5%6%9%48%
2520
21st to endDay
10%425%6%35%6%6%8%44%
2520
July1st to 10thDay
7%424435%5%7%10%48%
2520
11th to 20thDay
7%4245%35%46%9%50%
2445
21st to endDay
8%425%4345%7%11%48%
2546
August1st to 10thDay
8%5%26%5%46%6%8%9%42%
2328
11th to 20thDay
10%5%245%445%7%9%46%
2301
21st to endDay
10%4245%35%45%8%52%
2389
September1st to 10thDay
14%5%2343335%6%53%
2160
11th to 20thDay
10%424425%5%6%8%51%
2116
21st to endDay
11%42443345%6%53%
1903
October1st to 10thDay
14%6%35%5%33348%47%
1800
11th to 20thDay
16%8%2433335%5%48%
1800
21st to endDay
15%8%45%42445%6%43%
1980
November1st to 10thDay
9%6%25%4245%5%7%50%
1782
11th to 20thDay
13%7%37%6%2335%7%45%
1554
21st to endDay
17%11%445%3335%6%41%
1520
December1st to 10thDay
12%11%48%6%35%446%37%
1520
11th to 20thDay
11%9%48%6%445%5%7%36%
1918
21st to endDay
19%14%9%12%6%35%445%20%
2783
January1st to 10thNight
9%10%48%5%345%46%41%
2601
11th to 20thNight
11%11%6%10%7%45%45%6%33%
2354
21st to endNight
11%12%5%9%7%34447%34%
2574
February1st to 10thNight
14%11%5%9%6%45%45%6%34%
2340
11th to 20thNight
12%10%46%6%3445%6%41%
2273
21st to endNight
15%8%5%6%5%25%44441%
1809
March1st to 10thNight
12%7%38%5%24345%48%
1980
11th to 20thNight
16%9%36%4335%5%7%38%
1980
21st to endNight
23%10%47%7%45%45%6%26%
2178
April1st to 10thNight
12%7%26%5%3445%8%46%
1806
11th to 20thNight
15%9%35%6%335%5%5%42%
1775
21st to endNight
18%8%26%43435%6%41%
1724
May1st to 10thNight
14%6%46%5%445%6%8%39%
1620
11th to 20thNight
14%7%25%5%35%448%44%
1493
21st to endNight
10%5%246%45%5%7%8%44%
1551
June1st to 10thNight
6%4143345%8%10%52%
1440
11th to 20thNight
7%42444446%10%52%
1440
21st to endNight
7%3244345%6%11%50%
1440
July1st to 10thNight
6%322325%6%5%9%57%
1440
11th to 20thNight
4213325%46%9%60%
1512
21st to endNight
6%32443446%9%55%
1772
August1st to 10thNight
5%3246%346%8%11%50%
1611
11th to 20thNight
8%3244345%6%8%55%
1600
21st to endNight
6%32333446%7%60%
1966
September1st to 10thNight
11%42342345%6%56%
1800
11th to 20thNight
10%5%1442445%6%54%
1840
21st to endNight
8%5%235%2345%6%57%
2038
October1st to 10thNight
13%5%345%23446%51%
2160
11th to 20thNight
13%6%25%423346%52%
2160
21st to endNight
17%7%35%424335%47%
2376
November1st to 10thNight
7%5%2432346%7%57%
2294
11th to 20thNight
12%6%36%42435%7%49%
2622
21st to endNight
16%10%36%424345%44%
2660
December1st to 10thNight
11%10%48%5%34447%40%
2660
11th to 20thNight
12%9%48%6%24445%42%
3279
21st to endNight
19%15%9%11%6%3443424%
4884

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 10thDay
34%38%7%13%6%1
1560
11th to 20thDay
36%40%7%12%5%
1629
21st to endDay
41%35%9%10%4
1782
February1st to 10thDay
34%36%9%13%6%2
1620
11th to 20thDay
33%36%7%16%7%1
1583
21st to endDay
32%35%9%18%5%
1458
March1st to 10thDay
33%35%7%17%8%
1980
11th to 20thDay
35%35%9%14%5%1
1980
21st to endDay
39%35%9%11%41
2178
April1st to 10thDay
29%36%7%20%8%
2153
11th to 20thDay
32%34%6%18%9%1
2134
21st to endDay
34%35%9%15%7%
2232
May1st to 10thDay
34%37%8%15%6%1
2340
11th to 20thDay
32%37%8%16%8%
2404
21st to endDay
33%37%7%15%8%1
2725
June1st to 10thDay
26%37%12%19%6%
2520
11th to 20thDay
22%36%10%17%14%1
2520
21st to endDay
26%36%9%17%11%2
2520
July1st to 10thDay
21%37%12%19%9%2
2451
11th to 20thDay
22%37%9%18%12%2
2370
21st to endDay
21%37%9%23%10%1
2405
August1st to 10thDay
23%37%11%17%10%1
2314
11th to 20thDay
21%35%10%20%13%1
2301
21st to endDay
17%35%7%20%15%5%
2389
September1st to 10thDay
23%34%5%18%15%5%
2160
11th to 20thDay
22%35%7%21%13%1
2116
21st to endDay
20%36%6%22%15%2
1903
October1st to 10thDay
21%35%6%21%15%2
1800
11th to 20thDay
30%35%6%17%11%2
1800
21st to endDay
29%36%7%16%11%2
1980
November1st to 10thDay
20%39%9%18%12%2
1782
11th to 20thDay
27%38%8%17%10%1
1554
21st to endDay
28%38%10%15%8%
1520
December1st to 10thDay
31%38%10%15%7%
1520
11th to 20thDay
33%30%11%23%3
1915
21st to endDay
56%24%6%11%3
2783
January1st to 10thNight
29%39%7%17%8%1
2601
11th to 20thNight
31%40%8%13%7%
2354
21st to endNight
36%36%10%12%5%1
2574
February1st to 10thNight
34%35%6%14%9%2
2340
11th to 20thNight
29%36%7%17%9%2
2274
21st to endNight
31%34%7%17%10%2
1809
March1st to 10thNight
26%35%7%20%11%1
1980
11th to 20thNight
32%35%8%16%8%1
1980
21st to endNight
42%36%8%9%5%1
2178
April1st to 10thNight
25%35%8%18%12%2
1806
11th to 20thNight
31%34%418%10%3
1775
21st to endNight
30%35%9%17%9%
1724
May1st to 10thNight
29%36%8%17%8%2
1620
11th to 20thNight
28%36%8%15%11%1
1494
21st to endNight
25%38%9%18%8%2
1552
June1st to 10thNight
21%37%14%19%9%1
1440
11th to 20thNight
20%36%10%17%14%3
1440
21st to endNight
21%35%10%15%15%3
1440
July1st to 10thNight
17%37%10%23%10%3
1400
11th to 20thNight
17%36%9%22%14%2
1464
21st to endNight
20%37%7%21%13%1
1673
August1st to 10thNight
18%36%13%20%11%2
1601
11th to 20thNight
19%34%9%22%15%1
1600
21st to endNight
14%35%7%20%18%7%
1966
September1st to 10thNight
18%35%420%18%6%
1800
11th to 20thNight
24%35%7%19%14%2
1840
21st to endNight
17%35%6%22%17%3
2038
October1st to 10thNight
17%35%8%19%18%4
2160
11th to 20thNight
27%35%6%16%12%3
2160
21st to endNight
29%35%6%16%13%1
2376
November1st to 10thNight
15%40%12%17%13%4
2294
11th to 20thNight
24%38%6%20%9%2
2622
21st to endNight
28%38%6%17%10%2
2660
December1st to 10thNight
30%38%9%17%6%1
2660
11th to 20thNight
33%31%7%21%8%
3281
21st to endNight
55%24%5%12%4
4884

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 10thDay
18%19%31%24%6%1
270
11th to 20thDay
23%14%42%19%3
243
21st to endDay
20%14%44%19%3
264
February1st to 10thDay
20%20%39%18%3
240
11th to 20thDay
20%20%36%15%8%1
240
21st to endDay
22%15%45%14%4
198
March1st to 10thDay
20%19%43%16%3
240
11th to 20thDay
23%13%38%20%6%
240
21st to endDay
38%17%27%14%4
264
April1st to 10thDay
23%16%34%20%6%1
413
11th to 20thDay
21%15%32%23%8%1
412
21st to endDay
21%17%34%20%7%1
492
May1st to 10thDay
21%14%33%22%9%2
603
11th to 20thDay
22%11%29%25%10%2
625
21st to endDay
19%9%25%27%17%4
679
June1st to 10thDay
7%5%20%35%26%8%
630
11th to 20thDay
8%425%38%20%4
630
21st to endDay
10%9%32%30%16%3
630
July1st to 10thDay
7%217%32%28%13%
621
11th to 20thDay
8%424%35%23%6%
618
21st to endDay
6%320%42%25%4
684
August1st to 10thDay
7%319%41%24%6%
626
11th to 20thDay
11%417%35%27%6%
615
21st to endDay
10%217%36%27%8%
508
September1st to 10thDay
15%5%22%27%25%6%
450
11th to 20thDay
8%325%33%23%7%
406
21st to endDay
11%9%29%26%21%4
270
October1st to 10thDay
20%7%31%24%12%6%
270
11th to 20thDay
13%25%34%18%9%1
270
21st to endDay
23%17%29%20%9%2
297
November1st to 10thDay
14%12%45%21%6%2
270
11th to 20thDay
18%15%35%23%7%2
270
21st to endDay
24%11%35%23%6%
270
December1st to 10thDay
10%17%42%19%9%3
270
11th to 20thDay
17%17%37%22%6%1
270
21st to endDay
23%24%34%18%2
297
January1st to 10thNight
14%14%41%24%7%
950
11th to 20thNight
15%15%41%22%6%1
906
21st to endNight
17%14%41%26%4
990
February1st to 10thNight
20%13%39%25%3
900
11th to 20thNight
16%14%39%26%4
879
21st to endNight
20%15%41%20%41
625
March1st to 10thNight
16%12%41%23%6%
540
11th to 20thNight
19%13%34%27%6%
540
21st to endNight
27%11%37%21%5%
594
April1st to 10thNight
15%15%42%24%4
540
11th to 20thNight
21%12%37%24%5%
533
21st to endNight
20%9%40%23%7%1
540
May1st to 10thNight
16%9%34%34%6%1
540
11th to 20thNight
15%8%32%32%13%
531
21st to endNight
12%5%29%36%17%1
584
June1st to 10thNight
8%324%41%22%2
540
11th to 20thNight
8%426%43%17%1
540
21st to endNight
7%429%43%17%
540
July1st to 10thNight
6%215%40%33%3
525
11th to 20thNight
5%121%46%25%2
522
21st to endNight
7%116%47%28%
591
August1st to 10thNight
4217%50%25%3
537
11th to 20thNight
8%214%43%30%3
534
21st to endNight
7%213%43%31%3
594
September1st to 10thNight
12%418%37%26%3
540
11th to 20thNight
12%421%37%23%3
540
21st to endNight
10%5%26%37%20%2
598
October1st to 10thNight
15%6%30%31%16%2
720
11th to 20thNight
16%10%40%26%8%
720
21st to endNight
19%12%36%26%7%
792
November1st to 10thNight
9%11%39%31%9%1
740
11th to 20thNight
14%15%41%23%7%
912
21st to endNight
20%13%36%24%6%
950
December1st to 10thNight
17%13%40%25%5%1
950
11th to 20thNight
19%10%38%27%6%
950
21st to endNight
20%17%38%23%3
1045
Page generated at 2024-01-08 21:31:24. Version ac07

Copyright 2024 Attilla Danko


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