Argyle
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Argyle clear sky chart from 2005-11-06 to 2024-01-10.

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
21%
23527
8%
74489
4%
23471
26%
23471
7%
62311

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
10%
830
3%
2786
1%
827
12%
827
3%
2523
January11th to 20thNight
12%
720
4%
2340
1%
720
15%
720
3%
2117
January21st to endNight
11%
792
5%
2574
1%
792
15%
792
3%
2325
February1st to 10thNight
8%
720
4%
2340
1%
720
12%
720
4%
2098
February11th to 20thNight
11%
703
5%
2276
1%
700
16%
700
3%
2053
February21st to endNight
16%
592
8%
1812
3%
592
22%
592
8%
1501
March1st to 10thNight
13%
720
8%
2023
3%
720
19%
720
6%
1730
March11th to 20thNight
19%
720
9%
1980
3%
720
24%
720
9%
1653
March21st to endNight
19%
792
14%
2178
3%
792
29%
792
11%
1739
April1st to 10thNight
15%
630
9%
1890
3%
630
21%
630
8%
1573
April11th to 20thNight
17%
534
13%
1621
3%
534
27%
534
10%
1283
April21st to endNight
23%
540
11%
1620
4%
540
29%
540
10%
1306
May1st to 10thNight
21%
540
9%
1620
3%
540
27%
540
9%
1337
May11th to 20thNight
23%
532
12%
1521
6%
532
29%
532
10%
1245
May21st to endNight
27%
583
8%
1551
5%
582
30%
582
10%
1299
June1st to 10thNight
24%
518
7%
1418
4%
518
28%
518
9%
1208
June11th to 20thNight
30%
360
9%
1260
6%
360
35%
360
8%
1031
June21st to endNight
30%
360
4%
1260
5%
360
31%
360
5%
1093
July1st to 10thNight
29%
350
5%
1225
5%
350
32%
350
7%
1022
July11th to 20thNight
31%
445
5%
1390
5%
445
32%
445
7%
1208
July21st to endNight
29%
590
7%
1672
6%
558
31%
558
9%
1425
August1st to 10thNight
34%
538
7%
1600
4%
534
36%
534
10%
1317
August11th to 20thNight
31%
532
10%
1596
7%
532
33%
532
9%
1326
August21st to endNight
36%
594
11%
1818
6%
594
39%
594
11%
1460
September1st to 10thNight
39%
550
13%
1810
8%
550
44%
550
12%
1383
September11th to 20thNight
34%
720
15%
1980
8%
720
40%
720
14%
1540
September21st to endNight
33%
720
12%
1980
7%
720
37%
720
11%
1597
October1st to 10thNight
33%
720
13%
2142
6%
720
39%
720
13%
1647
October11th to 20thNight
28%
720
13%
2160
5%
720
36%
720
12%
1681
October21st to endNight
22%
792
10%
2403
4%
792
27%
792
9%
1955
November1st to 10thNight
27%
751
10%
2430
5%
751
32%
751
10%
1923
November11th to 20thNight
19%
850
10%
2660
6%
850
24%
850
7%
2215
November21st to endNight
17%
850
6%
2660
3%
850
21%
850
5%
2271
December1st to 10thNight
14%
850
3%
2660
0%
850
17%
850
4%
2385
December11th to 20thNight
11%
849
6%
3236
1%
849
15%
849
3%
2835
December21st to endNight
14%
920
3%
4997
1%
907
17%
907
2%
4007

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
22%10%47%6%3445%6%29%
74867
Night
22%11%48%6%34446%26%
74775
TransparencyDay
38%35%7%12%6%1
74573
Night
41%35%7%12%5%
74604
SeeingDay
30%17%30%16%6%1
15602
Night
30%15%27%21%7%1
23543

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 10thDay
20%18%6%13%9%45%44413%
1360
11th to 20thDay
26%15%6%9%9%46%445%13%
1620
21st to endDay
16%10%6%14%12%45%5%5%6%16%
1782
February1st to 10thDay
21%14%7%11%11%45%5%5%413%
1620
11th to 20thDay
18%13%7%12%11%5%5%445%17%
1573
21st to endDay
13%12%7%11%9%35%5%5%6%24%
1440
March1st to 10thDay
18%11%6%10%9%44445%25%
1932
11th to 20thDay
19%9%5%9%7%3435%6%31%
1980
21st to endDay
20%9%5%7%6%33447%32%
2178
April1st to 10thDay
25%12%36%5%35%44429%
2070
11th to 20thDay
21%8%45%5%2345%6%37%
2284
21st to endDay
25%9%35%424446%35%
2340
May1st to 10thDay
26%10%47%6%34435%30%
2340
11th to 20thDay
21%8%3443445%6%38%
2371
21st to endDay
24%9%35%5%3445%6%32%
2724
June1st to 10thDay
29%7%34434346%32%
2556
11th to 20thDay
23%6%45%5%34446%36%
2700
21st to endDay
27%9%36%5%345%5%7%27%
2700
July1st to 10thDay
23%8%35%4345%6%7%31%
2700
11th to 20thDay
23%9%36%6%45%5%6%8%26%
2501
21st to endDay
24%9%46%5%35%6%5%7%26%
2548
August1st to 10thDay
20%8%25%5%35%6%6%7%32%
2327
11th to 20thDay
23%8%35%5%25%5%6%6%31%
2304
21st to endDay
19%7%244345%5%7%40%
2538
September1st to 10thDay
16%6%25%5%3345%7%44%
2147
11th to 20thDay
18%7%26%5%34346%44%
1980
21st to endDay
20%7%26%433346%42%
1980
October1st to 10thDay
20%7%35%42445%7%39%
1818
11th to 20thDay
20%8%25%5%35%47%6%34%
1800
21st to endDay
21%10%47%7%34446%30%
1949
November1st to 10thDay
23%8%37%5%3345%5%34%
1648
11th to 20thDay
21%13%6%9%7%34447%23%
1520
21st to endDay
21%15%6%9%7%35%446%19%
1520
December1st to 10thDay
25%16%7%10%6%45%435%16%
1520
11th to 20thDay
29%15%6%8%7%45%445%14%
1906
21st to endDay
24%12%7%10%7%3445%5%19%
2591
January1st to 10thNight
21%18%7%14%8%44345%13%
2786
11th to 20thNight
22%15%6%11%8%5%5%5%46%14%
2340
21st to endNight
15%15%7%15%10%5%6%45%5%13%
2574
February1st to 10thNight
21%13%8%14%11%45%43415%
2340
11th to 20thNight
20%12%6%11%10%46%5%4417%
2273
21st to endNight
14%12%6%10%8%45%5%5%6%25%
1812
March1st to 10thNight
19%9%5%11%8%46%445%25%
2014
11th to 20thNight
20%9%5%7%7%45%5%5%6%27%
1979
21st to endNight
18%10%37%5%34446%34%
2178
April1st to 10thNight
24%12%36%6%33446%29%
1890
11th to 20thNight
23%10%36%434347%33%
1621
21st to endNight
26%8%25%5%25%45%8%31%
1620
May1st to 10thNight
24%10%45%5%35%45%7%30%
1620
11th to 20thNight
26%9%25%5%335%5%7%30%
1520
21st to endNight
24%10%36%6%34446%30%
1550
June1st to 10thNight
28%9%46%5%245%5%7%26%
1418
11th to 20thNight
20%10%46%6%35%446%33%
1260
21st to endNight
30%12%36%5%34346%26%
1260
July1st to 10thNight
25%11%37%6%3446%8%24%
1260
11th to 20thNight
27%12%47%6%35%45%5%21%
1433
21st to endNight
27%13%46%6%34446%24%
1770
August1st to 10thNight
22%11%36%5%23447%33%
1612
11th to 20thNight
25%13%37%424347%28%
1596
21st to endNight
20%8%35%42445%6%37%
1818
September1st to 10thNight
19%7%25%43446%6%40%
1810
11th to 20thNight
21%7%35%334346%41%
1980
21st to endNight
22%8%35%5%23446%38%
1980
October1st to 10thNight
21%7%25%5%3445%6%39%
2142
11th to 20thNight
18%8%36%5%3446%7%39%
2160
21st to endNight
25%9%46%5%3445%6%32%
2403
November1st to 10thNight
19%8%47%5%3445%6%34%
2430
11th to 20thNight
20%12%5%8%7%445%5%6%24%
2660
21st to endNight
20%14%5%8%6%4445%6%23%
2660
December1st to 10thNight
27%14%5%9%6%45%45%5%15%
2660
11th to 20thNight
26%14%5%10%7%34445%16%
3293
21st to endNight
24%14%5%9%6%34345%22%
5053

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
48%39%6%6%2
1361
11th to 20thDay
46%41%6%7%
1620
21st to endDay
44%36%6%12%2
1782
February1st to 10thDay
49%35%7%6%3
1620
11th to 20thDay
49%36%6%7%2
1581
21st to endDay
44%35%8%10%31
1440
March1st to 10thDay
43%35%8%10%5%1
1936
11th to 20thDay
35%35%8%14%7%1
1980
21st to endDay
36%34%7%15%8%1
2178
April1st to 10thDay
38%35%6%11%10%1
2070
11th to 20thDay
34%34%417%10%1
2284
21st to endDay
34%34%7%14%9%1
2340
May1st to 10thDay
41%35%412%6%1
2340
11th to 20thDay
33%35%6%14%10%1
2375
21st to endDay
33%37%8%12%9%1
2724
June1st to 10thDay
39%35%6%15%5%1
2556
11th to 20thDay
36%35%6%13%8%2
2700
21st to endDay
42%37%8%9%3
2700
July1st to 10thDay
36%38%9%10%5%1
2625
11th to 20thDay
38%37%7%12%5%1
2421
21st to endDay
36%38%6%15%5%
2406
August1st to 10thDay
37%36%7%13%7%
2314
11th to 20thDay
37%35%7%13%8%
2304
21st to endDay
32%35%6%16%9%1
2538
September1st to 10thDay
28%36%7%14%13%1
2147
11th to 20thDay
29%35%7%16%11%2
1980
21st to endDay
33%35%415%12%2
1980
October1st to 10thDay
30%35%8%19%8%
1818
11th to 20thDay
35%35%7%18%5%
1800
21st to endDay
36%36%6%13%8%1
1949
November1st to 10thDay
33%40%7%13%7%
1648
11th to 20thDay
39%39%7%12%4
1520
21st to endDay
43%40%8%8%1
1520
December1st to 10thDay
46%38%5%9%2
1520
11th to 20thDay
54%31%7%7%1
1905
21st to endDay
51%23%15%8%3
2591
January1st to 10thNight
48%38%6%5%1
2786
11th to 20thNight
45%41%6%6%1
2340
21st to endNight
48%37%5%7%2
2574
February1st to 10thNight
50%35%7%7%2
2340
11th to 20thNight
50%36%5%7%3
2276
21st to endNight
39%35%9%13%3
1812
March1st to 10thNight
42%35%7%10%5%1
2023
11th to 20thNight
39%35%9%10%6%1
1980
21st to endNight
33%35%5%17%9%1
2178
April1st to 10thNight
40%35%6%11%7%1
1890
11th to 20thNight
35%34%5%15%10%1
1621
21st to endNight
36%35%6%15%8%
1620
May1st to 10thNight
39%35%6%14%7%
1620
11th to 20thNight
36%35%5%15%8%1
1521
21st to endNight
37%37%6%14%5%1
1551
June1st to 10thNight
41%35%6%14%31
1418
11th to 20thNight
40%35%7%11%6%1
1260
21st to endNight
46%35%6%8%4
1260
July1st to 10thNight
39%38%10%9%4
1225
11th to 20thNight
43%37%5%10%31
1390
21st to endNight
40%37%5%12%5%1
1672
August1st to 10thNight
38%35%7%15%5%
1600
11th to 20thNight
41%34%413%8%
1596
21st to endNight
35%35%5%16%8%
1818
September1st to 10thNight
32%35%5%17%10%1
1810
11th to 20thNight
30%35%418%13%1
1980
21st to endNight
35%35%412%13%2
1980
October1st to 10thNight
30%35%8%16%10%
2142
11th to 20thNight
32%35%8%18%7%
2160
21st to endNight
37%35%6%12%8%1
2403
November1st to 10thNight
30%40%9%15%7%
2430
11th to 20thNight
37%39%7%11%5%
2660
21st to endNight
40%40%9%10%2
2660
December1st to 10thNight
46%39%7%6%1
2660
11th to 20thNight
50%32%6%10%3
3295
21st to endNight
53%23%9%12%2
5053

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
41%22%28%7%2
179
11th to 20thDay
34%21%29%12%3
340
21st to endDay
25%26%34%13%2
374
February1st to 10thDay
37%19%32%10%1
340
11th to 20thDay
35%29%23%11%2
336
21st to endDay
31%23%31%13%2
328
March1st to 10thDay
32%22%33%10%3
420
11th to 20thDay
35%23%27%9%5%
420
21st to endDay
30%24%28%12%5%1
462
April1st to 10thDay
40%24%24%9%3
420
11th to 20thDay
32%21%33%10%3
412
21st to endDay
35%17%29%12%5%1
420
May1st to 10thDay
33%23%28%12%31
423
11th to 20thDay
26%22%29%18%5%1
517
21st to endDay
31%14%29%19%6%1
680
June1st to 10thDay
32%14%27%20%6%1
630
11th to 20thDay
24%14%33%21%8%1
630
21st to endDay
35%11%28%19%6%1
630
July1st to 10thDay
28%8%30%22%10%2
620
11th to 20thDay
26%8%33%24%8%2
540
21st to endDay
25%10%36%21%8%1
488
August1st to 10thDay
21%10%34%26%8%2
446
11th to 20thDay
26%12%34%17%10%3
439
21st to endDay
26%12%28%20%11%3
495
September1st to 10thDay
18%13%34%25%8%2
450
11th to 20thDay
25%12%31%20%7%4
450
21st to endDay
23%14%32%20%7%4
450
October1st to 10thDay
26%12%28%21%10%2
369
11th to 20thDay
25%17%29%19%7%3
360
21st to endDay
30%19%29%15%6%1
396
November1st to 10thDay
28%18%29%16%7%1
365
11th to 20thDay
36%20%26%13%5%1
370
21st to endDay
34%21%30%12%21
370
December1st to 10thDay
36%20%30%11%2
370
11th to 20thDay
42%26%21%10%1
370
21st to endDay
42%24%21%10%31
293
January1st to 10thNight
33%21%29%13%3
830
11th to 20thNight
36%16%29%16%3
720
21st to endNight
27%23%31%16%3
792
February1st to 10thNight
34%18%30%17%1
720
11th to 20thNight
34%23%25%14%3
703
21st to endNight
24%20%34%17%5%
592
March1st to 10thNight
28%20%32%16%4
720
11th to 20thNight
28%18%27%20%6%1
720
21st to endNight
27%17%31%18%6%1
792
April1st to 10thNight
35%17%30%17%3
630
11th to 20thNight
29%17%33%17%4
534
21st to endNight
32%14%26%20%7%
540
May1st to 10thNight
29%14%32%21%41
540
11th to 20thNight
29%11%33%22%5%
532
21st to endNight
28%10%30%27%5%1
583
June1st to 10thNight
33%8%30%23%7%
518
11th to 20thNight
24%7%30%31%8%1
360
21st to endNight
33%5%24%28%9%
360
July1st to 10thNight
28%5%25%30%11%
350
11th to 20thNight
25%6%27%30%11%1
445
21st to endNight
26%8%25%32%8%
590
August1st to 10thNight
24%6%26%32%11%1
538
11th to 20thNight
29%8%22%29%11%
532
21st to endNight
23%5%26%31%14%2
594
September1st to 10thNight
22%8%26%31%12%1
550
11th to 20thNight
25%9%25%23%15%2
720
21st to endNight
27%9%25%24%12%2
720
October1st to 10thNight
27%10%26%25%12%1
720
11th to 20thNight
25%14%27%23%9%2
720
21st to endNight
32%15%26%22%6%
792
November1st to 10thNight
28%12%27%23%9%1
751
11th to 20thNight
31%18%26%19%6%
850
21st to endNight
32%20%24%18%6%
850
December1st to 10thNight
36%17%28%15%3
850
11th to 20thNight
37%23%25%13%2
850
21st to endNight
36%21%22%18%3
935
Page generated at 2024-01-07 11:06:51. Version ac07

Copyright 2024 Attilla Danko


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