Augusta
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Augusta 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%
15533
16%
49190
7%
15501
37%
15501
19%
33162

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
20%
780
18%
2716
6%
776
35%
776
17%
1739
January16th to endNight
16%
832
15%
2912
4%
832
31%
832
14%
1940
February1st to 15thNight
18%
764
14%
2453
5%
761
30%
761
13%
1729
February16th to endNight
18%
683
18%
2049
5%
683
34%
683
18%
1411
March1st to 15thNight
15%
764
14%
2249
4%
764
28%
764
15%
1649
March16th to endNight
24%
768
19%
2087
6%
768
34%
768
21%
1403
April1st to 15thNight
20%
703
16%
1781
4%
703
28%
703
18%
1305
April16th to endNight
25%
540
15%
1620
5%
540
33%
540
18%
1132
May1st to 15thNight
28%
540
12%
1620
7%
540
34%
540
17%
1166
May16th to endNight
26%
423
11%
1545
8%
422
34%
422
12%
1118
June1st to 15thNight
28%
360
9%
1317
6%
360
36%
360
12%
972
June16th to endNight
38%
360
9%
1327
9%
360
44%
360
19%
887
July1st to 15thNight
44%
340
10%
1360
12%
340
49%
340
19%
863
July16th to endNight
45%
376
11%
1418
13%
354
50%
354
20%
896
August1st to 15thNight
44%
521
12%
1592
8%
519
47%
519
22%
1063
August16th to endNight
46%
621
20%
1767
12%
621
50%
621
32%
1097
September1st to 15thNight
40%
720
18%
1896
8%
720
46%
720
32%
1220
September16th to endNight
41%
717
27%
1980
15%
717
51%
717
34%
1183
October1st to 15thNight
35%
720
20%
2045
10%
720
45%
720
25%
1349
October16th to endNight
22%
768
16%
2476
7%
768
33%
768
18%
1669
November1st to 15thNight
30%
760
20%
2472
10%
760
42%
760
20%
1615
November16th to endNight
26%
794
20%
2597
8%
794
40%
794
17%
1690
December1st to 15thNight
17%
825
15%
2902
4%
825
32%
825
14%
2015
December16th to endNight
16%
854
17%
3009
4%
854
32%
854
14%
2051

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
18%7%25%434446%37%
49435
Night
18%7%34424446%38%
49360
TransparencyDay
46%6%11%20%13%1
49123
Night
46%5%11%21%12%1
49190
SeeingDay
23%13%30%19%8%2
6633
Night
22%12%32%24%7%
15533

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%7%35%425%446%38%
1552
16th to endDay
16%8%3442445%5%39%
1664
February1st to 15thDay
16%10%46%5%35%345%34%
1737
16th to endDay
14%10%47%5%25%45%5%34%
1710
March1st to 15thDay
19%9%36%5%43346%33%
1938
16th to endDay
17%8%34423345%43%
2136
April1st to 15thDay
19%7%35%424436%37%
2167
16th to endDay
20%5%25%43445%6%37%
2340
May1st to 15thDay
26%8%245%33436%30%
2332
16th to endDay
22%5%25%42446%7%33%
2579
June1st to 15thDay
27%7%3442345%7%29%
2640
16th to endDay
21%6%245%35%447%32%
2627
July1st to 15thDay
13%6%24435%5%7%8%37%
2520
16th to endDay
14%5%26%5%35%6%6%7%35%
2654
August1st to 15thDay
14%5%25%5%36%45%8%37%
2346
16th to endDay
13%32432445%8%47%
2432
September1st to 15thDay
15%42443445%5%46%
2064
16th to endDay
14%413322247%52%
1980
October1st to 15thDay
19%6%15%5%23435%42%
1914
16th to endDay
20%6%25%5%33335%40%
1746
November1st to 15thDay
20%6%25%324446%39%
1716
16th to endDay
21%6%24413335%43%
1690
December1st to 15thDay
23%8%24424346%35%
1388
16th to endDay
22%11%25%43333433%
1563
January1st to 15thNight
15%8%3443445%6%39%
2716
16th to endNight
15%9%36%4245%45%36%
2912
February1st to 15thNight
15%7%36%7%45%5%46%32%
2452
16th to endNight
16%10%35%434346%38%
2049
March1st to 15thNight
20%10%35%6%25%43433%
2236
16th to endNight
16%7%34423445%42%
2087
April1st to 15thNight
20%8%4443444436%
1781
16th to endNight
22%7%245%2345%436%
1620
May1st to 15thNight
21%7%445%35%45%8%31%
1620
16th to endNight
24%8%35%5%2445%7%28%
1543
June1st to 15thNight
25%7%36%5%34446%27%
1317
16th to endNight
21%6%143145%6%8%36%
1327
July1st to 15thNight
15%6%345%35%5%5%9%35%
1440
16th to endNight
15%4335%25%47%10%36%
1514
August1st to 15thNight
13%6%25%435%5%5%7%39%
1602
16th to endNight
12%42442346%7%48%
1767
September1st to 15thNight
15%5%23314336%49%
1896
16th to endNight
13%414324337%52%
1980
October1st to 15thNight
18%6%2432345%6%43%
2045
16th to endNight
22%6%24434346%38%
2476
November1st to 15thNight
18%6%25%324347%41%
2472
16th to endNight
17%6%34434446%41%
2597
December1st to 15thNight
22%9%25%5%24335%35%
2902
16th to endNight
22%9%34323445%35%
3009

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
44%6%12%20%14%1
1553
16th to endDay
44%5%12%23%12%1
1664
February1st to 15thDay
52%410%19%11%1
1740
16th to endDay
50%412%17%12%3
1710
March1st to 15thDay
52%411%17%12%2
1948
16th to endDay
43%49%19%18%4
2136
April1st to 15thDay
48%48%18%16%3
2167
16th to endDay
46%6%10%19%13%3
2340
May1st to 15thDay
54%5%7%17%12%2
2332
16th to endDay
48%7%12%18%11%1
2583
June1st to 15thDay
54%6%11%18%8%1
2640
16th to endDay
50%7%10%17%12%
2627
July1st to 15thDay
41%8%15%23%10%
2371
16th to endDay
43%8%15%21%10%
2487
August1st to 15thDay
44%7%15%23%8%
2332
16th to endDay
34%7%14%24%17%1
2432
September1st to 15thDay
38%6%10%25%18%1
2064
16th to endDay
32%410%29%21%1
1980
October1st to 15thDay
44%410%24%14%1
1914
16th to endDay
47%411%24%11%
1746
November1st to 15thDay
44%6%13%20%13%1
1716
16th to endDay
43%414%20%15%1
1690
December1st to 15thDay
49%5%12%21%10%
1388
16th to endDay
54%48%16%14%1
1563
January1st to 15thNight
44%5%13%23%11%1
2716
16th to endNight
48%5%11%19%13%2
2912
February1st to 15thNight
51%5%12%17%11%1
2453
16th to endNight
48%410%20%13%2
2049
March1st to 15thNight
54%48%18%10%2
2249
16th to endNight
42%5%10%18%18%4
2087
April1st to 15thNight
50%5%7%17%16%2
1781
16th to endNight
48%6%10%18%12%3
1620
May1st to 15thNight
51%6%10%16%13%2
1620
16th to endNight
55%7%10%15%10%
1545
June1st to 15thNight
57%6%11%15%7%1
1317
16th to endNight
44%9%14%19%11%1
1327
July1st to 15thNight
43%8%15%22%10%
1360
16th to endNight
41%9%17%22%9%
1418
August1st to 15thNight
41%9%16%22%10%
1592
16th to endNight
33%8%16%27%14%
1767
September1st to 15thNight
36%5%12%28%15%1
1896
16th to endNight
32%411%32%17%1
1980
October1st to 15thNight
41%6%11%25%14%1
2045
16th to endNight
47%5%12%22%11%
2476
November1st to 15thNight
44%5%12%22%13%1
2472
16th to endNight
43%5%12%21%14%1
2597
December1st to 15thNight
52%49%21%12%
2902
16th to endNight
49%5%11%19%12%1
3009

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
25%23%27%17%5%
90
16th to endDay
25%27%34%11%2
96
February1st to 15thDay
30%16%31%19%2
275
16th to endDay
21%21%33%19%4
291
March1st to 15thDay
30%20%32%13%3
312
16th to endDay
21%26%29%12%6%3
288
April1st to 15thDay
28%15%34%13%6%2
270
16th to endDay
26%19%30%14%5%3
270
May1st to 15thDay
37%11%27%15%5%1
288
16th to endDay
23%12%39%16%5%
331
June1st to 15thDay
28%11%27%20%10%
435
16th to endDay
21%10%31%25%8%1
422
July1st to 15thDay
14%8%39%22%11%3
305
16th to endDay
15%7%35%24%12%3
326
August1st to 15thDay
15%7%30%27%15%2
313
16th to endDay
16%8%24%27%17%5%
332
September1st to 15thDay
19%6%29%24%13%4
315
16th to endDay
17%10%27%19%14%10%
314
October1st to 15thDay
22%11%25%22%13%5%
298
16th to endDay
28%13%31%19%7%
288
November1st to 15thDay
26%12%28%21%8%2
280
16th to endDay
28%16%25%21%8%1
285
December1st to 15thDay
25%15%40%13%5%
113
16th to endDay
41%23%26%8%
96
January1st to 15thNight
22%17%36%21%2
780
16th to endNight
23%17%37%19%3
832
February1st to 15thNight
20%18%36%22%2
764
16th to endNight
22%15%38%19%4
683
March1st to 15thNight
27%15%36%15%3
764
16th to endNight
21%17%32%22%5%
768
April1st to 15thNight
25%17%34%18%4
703
16th to endNight
25%15%31%22%4
540
May1st to 15thNight
25%10%33%25%5%
540
16th to endNight
26%9%30%26%6%
423
June1st to 15thNight
27%7%29%27%7%
360
16th to endNight
22%230%34%10%
360
July1st to 15thNight
17%426%35%15%
340
16th to endNight
15%226%41%12%
376
August1st to 15thNight
16%328%35%14%
521
16th to endNight
15%426%34%16%1
621
September1st to 15thNight
16%5%33%28%14%1
720
16th to endNight
16%7%30%26%17%2
717
October1st to 15thNight
22%8%27%27%12%1
720
16th to endNight
26%14%33%18%6%
768
November1st to 15thNight
23%10%30%25%8%1
760
16th to endNight
22%16%31%21%7%
794
December1st to 15thNight
28%12%35%18%4
825
16th to endNight
29%16%33%18%2
854
Page generated at 2018-03-12 13:28:10. Version ac04

Copyright 2018 A. Danko


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