Palgrave Conservation Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Palgrave Conservation Area clear sky chart from 2005-11-05 to 2018-03-11.

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%
15512
14%
48893
7%
15474
35%
15474
16%
34540

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%
779
8%
2671
2%
776
18%
776
6%
2150
January16th to endNight
15%
832
9%
2704
3%
832
22%
832
8%
2145
February1st to 15thNight
10%
761
11%
2482
1%
761
21%
761
8%
1931
February16th to endNight
15%
683
12%
2181
3%
683
25%
683
10%
1638
March1st to 15thNight
16%
764
13%
2101
4%
764
23%
764
12%
1577
March16th to endNight
23%
768
20%
2112
8%
768
34%
768
21%
1443
April1st to 15thNight
19%
718
14%
1828
4%
718
25%
718
19%
1330
April16th to endNight
29%
545
19%
1625
8%
545
38%
545
23%
1071
May1st to 15thNight
38%
501
17%
1581
10%
501
46%
501
24%
1045
May16th to endNight
38%
374
17%
1497
12%
374
52%
374
26%
831
June1st to 15thNight
38%
360
13%
1440
9%
360
50%
360
19%
864
June16th to endNight
45%
360
15%
1266
13%
360
53%
360
27%
730
July1st to 15thNight
54%
340
17%
1267
19%
340
62%
340
32%
659
July16th to endNight
50%
499
16%
1531
12%
467
56%
467
31%
890
August1st to 15thNight
53%
539
16%
1609
9%
536
58%
536
34%
931
August16th to endNight
50%
612
23%
1758
12%
612
57%
612
33%
1054
September1st to 15thNight
47%
720
20%
1824
9%
720
53%
720
34%
1159
September16th to endNight
49%
717
23%
1995
15%
717
54%
717
33%
1238
October1st to 15thNight
30%
720
16%
2160
11%
720
37%
720
20%
1494
October16th to endNight
18%
768
12%
2304
5%
768
27%
768
12%
1753
November1st to 15thNight
26%
760
16%
2585
13%
760
33%
760
15%
1818
November16th to endNight
19%
780
10%
2730
5%
780
27%
780
9%
2093
December1st to 15thNight
12%
780
5%
2730
2%
780
16%
780
6%
2241
December16th to endNight
8%
832
6%
2912
1%
832
14%
832
4%
2455

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%9%47%6%35%45%7%30%
49725
Night
14%9%47%6%35%45%6%33%
49071
Cloud CoverDay
14%9%47%6%35%45%7%30%
49735
Night
14%8%46%6%35%45%6%34%
49075
TransparencyDay
52%6%12%18%9%
49421
Night
49%7%12%19%10%1
48893
SeeingDay
18%17%29%19%9%4
6092
Night
18%17%31%22%9%1
15517

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
14%16%6%11%8%45%5%5%417%
1594
16th to endDay
11%17%7%12%9%45%45%6%15%
1872
February1st to 15thDay
13%16%7%11%8%46%44416%
1710
16th to endDay
17%14%5%9%5%3445%423%
1578
March1st to 15thDay
13%12%6%8%8%35%345%27%
2083
16th to endDay
13%12%5%6%5%4444434%
2112
April1st to 15thDay
18%12%45%5%2335%7%30%
2125
16th to endDay
18%9%36%422346%38%
2340
May1st to 15thDay
16%7%26%5%35%447%35%
2370
16th to endDay
12%5%26%5%35%5%6%7%39%
2618
June1st to 15thDay
16%6%344245%6%9%35%
2520
16th to endDay
13%425%5%35%5%6%9%36%
2690
July1st to 15thDay
9%425%6%36%6%5%9%39%
2610
16th to endDay
11%6%35%6%36%6%6%9%34%
2530
August1st to 15thDay
9%6%26%7%35%5%7%8%36%
2340
16th to endDay
12%5%25%6%36%5%6%8%35%
2432
September1st to 15thDay
15%6%35%6%34437%37%
2133
16th to endDay
14%5%36%7%3435%8%37%
1965
October1st to 15thDay
20%8%47%6%35%345%31%
1800
16th to endDay
26%12%5%7%6%23445%21%
1920
November1st to 15thDay
12%12%48%6%25%5%5%8%27%
1599
16th to endDay
15%14%7%9%7%345%5%6%19%
1560
December1st to 15thDay
15%17%8%11%8%45%346%15%
1560
16th to endDay
19%15%8%9%6%45%5%5%5%14%
1664
January1st to 15thNight
16%15%6%10%6%45%5%4420%
2671
16th to endNight
11%11%6%10%9%47%6%5%6%19%
2704
February1st to 15thNight
13%12%5%8%9%45%447%23%
2480
16th to endNight
11%12%5%9%8%45%45%6%26%
2181
March1st to 15thNight
15%9%5%9%6%34435%30%
2089
16th to endNight
12%8%46%6%24435%42%
2112
April1st to 15thNight
17%8%35%5%25%446%34%
1828
16th to endNight
12%9%35%5%2435%5%41%
1625
May1st to 15thNight
15%425%5%3445%8%39%
1581
16th to endNight
11%424424346%50%
1495
June1st to 15thNight
12%4245%36%5%5%8%41%
1440
16th to endNight
10%325%4245%5%8%47%
1266
July1st to 15thNight
6%223434445%57%
1344
16th to endNight
7%423435%5%6%7%48%
1637
August1st to 15thNight
5%4144245%7%8%49%
1620
16th to endNight
8%5%1442445%6%51%
1758
September1st to 15thNight
12%41432446%6%49%
1824
16th to endNight
12%42442345%7%48%
1995
October1st to 15thNight
18%6%35%5%3345%6%37%
2160
16th to endNight
20%9%47%6%245%5%6%26%
2304
November1st to 15thNight
16%9%36%6%25%45%6%32%
2585
16th to endNight
16%11%48%6%35%5%5%7%24%
2730
December1st to 15thNight
18%14%5%8%6%45%6%5%6%17%
2730
16th to endNight
18%14%8%12%8%45%445%14%
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
15%16%5%10%8%35%46%5%17%
1594
16th to endDay
11%16%8%11%9%45%45%6%15%
1872
February1st to 15thDay
14%16%7%10%9%47%44417%
1710
16th to endDay
17%14%5%9%5%35%45%424%
1578
March1st to 15thDay
14%11%5%8%8%45%35%427%
2094
16th to endDay
13%12%47%6%34345%34%
2111
April1st to 15thDay
18%12%46%5%2435%7%29%
2125
16th to endDay
18%8%35%423345%38%
2340
May1st to 15thDay
16%6%36%5%35%447%35%
2370
16th to endDay
11%5%35%6%445%5%8%39%
2618
June1st to 15thDay
15%6%245%2447%9%35%
2520
16th to endDay
13%425%5%35%5%6%10%35%
2690
July1st to 15thDay
9%435%6%36%6%5%9%39%
2610
16th to endDay
10%6%36%6%46%6%7%8%33%
2530
August1st to 15thDay
8%6%26%7%45%6%6%9%36%
2340
16th to endDay
12%5%25%6%46%6%7%9%34%
2432
September1st to 15thDay
14%6%26%5%35%45%7%37%
2133
16th to endDay
14%6%36%6%34447%37%
1965
October1st to 15thDay
20%8%37%6%34445%31%
1800
16th to endDay
26%12%37%6%34445%21%
1920
November1st to 15thDay
13%12%47%6%36%45%8%27%
1599
16th to endDay
16%14%7%9%6%45%45%7%18%
1560
December1st to 15thDay
15%17%7%13%8%45%335%16%
1560
16th to endDay
19%14%7%10%6%45%5%5%5%14%
1664
January1st to 15thNight
18%14%5%10%6%45%445%20%
2671
16th to endNight
11%12%6%9%9%46%5%5%6%20%
2704
February1st to 15thNight
12%13%5%8%9%46%45%5%24%
2473
16th to endNight
11%13%49%8%45%5%5%6%25%
2181
March1st to 15thNight
16%9%48%7%34445%31%
2101
16th to endNight
13%8%35%5%24345%41%
2112
April1st to 15thNight
18%9%35%5%34446%34%
1828
16th to endNight
12%8%45%5%24346%41%
1625
May1st to 15thNight
14%4345%345%5%8%39%
1580
16th to endNight
11%325%32435%7%49%
1495
June1st to 15thNight
11%425%5%46%5%5%8%41%
1440
16th to endNight
9%425%4246%5%8%47%
1266
July1st to 15thNight
5%324424447%56%
1344
16th to endNight
7%423435%5%5%8%49%
1637
August1st to 15thNight
6%4144345%7%8%50%
1620
16th to endNight
8%4245%2445%6%52%
1758
September1st to 15thNight
11%3144235%5%7%48%
1824
16th to endNight
12%42442335%8%48%
1995
October1st to 15thNight
18%6%35%5%3435%6%38%
2160
16th to endNight
19%10%46%6%35%5%6%6%26%
2304
November1st to 15thNight
16%9%27%5%35%45%6%32%
2585
16th to endNight
17%10%48%6%35%5%5%7%24%
2730
December1st to 15thNight
18%14%5%8%7%36%5%5%6%18%
2730
16th to endNight
19%14%8%11%8%45%445%15%
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%7%9%10%4
1595
16th to endDay
68%7%9%10%3
1872
February1st to 15thDay
68%7%7%13%2
1712
16th to endDay
61%6%9%13%7%1
1578
March1st to 15thDay
59%6%10%14%9%
2094
16th to endDay
52%5%8%17%13%1
2112
April1st to 15thDay
54%410%19%11%
2125
16th to endDay
46%411%20%14%1
2340
May1st to 15thDay
48%6%9%21%12%
2370
16th to endDay
41%6%14%21%13%1
2622
June1st to 15thDay
43%7%14%22%12%
2520
16th to endDay
42%7%15%22%12%
2690
July1st to 15thDay
39%7%12%22%15%1
2458
16th to endDay
45%7%13%21%10%1
2373
August1st to 15thDay
43%6%16%19%12%1
2327
16th to endDay
43%6%15%23%9%1
2432
September1st to 15thDay
45%6%13%22%10%1
2133
16th to endDay
45%5%11%26%9%
1965
October1st to 15thDay
54%5%9%19%9%1
1800
16th to endDay
64%6%13%10%4
1920
November1st to 15thDay
53%8%13%16%7%
1599
16th to endDay
62%8%12%11%3
1560
December1st to 15thDay
71%6%11%8%2
1560
16th to endDay
69%7%10%9%2
1664
January1st to 15thNight
65%7%9%10%6%
2671
16th to endNight
61%9%12%12%3
2704
February1st to 15thNight
59%8%9%16%5%
2482
16th to endNight
56%7%12%15%7%
2181
March1st to 15thNight
55%5%10%18%8%
2101
16th to endNight
45%410%21%15%2
2112
April1st to 15thNight
50%411%18%14%
1828
16th to endNight
43%5%10%20%17%2
1625
May1st to 15thNight
42%6%10%23%15%1
1581
16th to endNight
34%5%14%27%14%2
1497
June1st to 15thNight
39%6%11%23%16%1
1440
16th to endNight
33%7%13%28%16%
1266
July1st to 15thNight
27%6%10%29%22%2
1267
16th to endNight
32%7%14%27%15%2
1531
August1st to 15thNight
29%7%19%28%14%1
1609
16th to endNight
32%6%11%30%17%1
1758
September1st to 15thNight
32%7%15%29%14%
1824
16th to endNight
34%5%13%32%12%
1995
October1st to 15thNight
46%6%10%21%13%1
2160
16th to endNight
54%9%12%16%6%
2304
November1st to 15thNight
50%7%12%19%9%1
2585
16th to endNight
58%8%14%14%3
2730
December1st to 15thNight
64%10%12%10%2
2730
16th to endNight
70%7%9%8%3
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
17%40%30%10%3
100
16th to endDay
31%27%31%8%1
144
February1st to 15thDay
28%42%22%5%
135
16th to endDay
31%41%24%2
120
March1st to 15thDay
20%28%28%17%4
310
16th to endDay
23%17%33%15%8%1
288
April1st to 15thDay
24%22%29%14%8%1
270
16th to endDay
22%21%27%14%9%4
270
May1st to 15thDay
22%13%30%18%9%5%
288
16th to endDay
14%17%31%22%11%2
331
June1st to 15thDay
20%13%31%21%11%
315
16th to endDay
14%14%36%24%8%2
485
July1st to 15thDay
11%9%31%28%11%6%
392
16th to endDay
10%8%32%28%13%6%
326
August1st to 15thDay
9%6%29%27%16%10%
313
16th to endDay
15%8%22%25%17%12%
332
September1st to 15thDay
10%8%28%23%14%13%
315
16th to endDay
15%8%21%23%20%10%
314
October1st to 15thDay
20%15%29%18%10%5%
315
16th to endDay
28%24%27%15%2
336
November1st to 15thDay
20%23%28%23%31
117
16th to endDay
20%26%42%7%3
90
December1st to 15thDay
24%32%32%10%1
90
16th to endDay
30%38%25%5%1
96
January1st to 15thNight
25%27%31%10%3
780
16th to endNight
17%22%36%19%4
832
February1st to 15thNight
20%28%34%13%2
764
16th to endNight
20%23%37%16%2
683
March1st to 15thNight
22%25%32%17%2
764
16th to endNight
18%19%35%18%8%
768
April1st to 15thNight
23%19%34%18%3
718
16th to endNight
16%14%34%24%8%
545
May1st to 15thNight
16%9%28%30%12%2
501
16th to endNight
11%8%37%27%14%
375
June1st to 15thNight
13%10%31%33%10%
360
16th to endNight
11%433%34%15%
360
July1st to 15thNight
5%5%29%40%17%1
340
16th to endNight
9%5%30%35%16%1
499
August1st to 15thNight
7%327%37%21%2
539
16th to endNight
11%427%29%23%2
612
September1st to 15thNight
13%9%25%25%19%6%
720
16th to endNight
15%7%23%29%19%5%
717
October1st to 15thNight
21%11%31%21%12%1
720
16th to endNight
24%21%31%18%4
768
November1st to 15thNight
21%18%29%21%8%1
760
16th to endNight
23%24%28%18%5%
780
December1st to 15thNight
27%26%28%14%2
780
16th to endNight
27%24%32%13%2
832
Page generated at 2018-03-12 13:28:13. Version ac04

Copyright 2018 A. Danko


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