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Talmage Observatory at Starfield
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Talmage Observatory at Starfield clear sky chart from 2005-11-05 to 2019-09-17.

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
29%
17304
19%
54707
9%
17272
41%
17272
21%
35532

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
19%
840
21%
2926
7%
836
37%
836
17%
1844
January16th to endNight
16%
896
18%
3136
4%
896
33%
896
15%
2019
February1st to 15thNight
15%
824
19%
2608
4%
821
32%
821
16%
1755
February16th to endNight
20%
735
20%
2205
7%
735
37%
735
18%
1468
March1st to 15thNight
18%
840
18%
2494
7%
840
31%
840
17%
1734
March16th to endNight
24%
896
22%
2402
7%
896
36%
896
25%
1570
April1st to 15thNight
22%
838
19%
2096
5%
838
31%
838
21%
1473
April16th to endNight
24%
643
17%
1889
6%
643
33%
643
20%
1285
May1st to 15thNight
27%
630
15%
1890
8%
630
34%
630
19%
1307
May16th to endNight
31%
487
11%
1801
9%
486
37%
486
14%
1250
June1st to 15thNight
34%
420
12%
1680
10%
420
45%
420
15%
1147
June16th to endNight
43%
420
10%
1680
12%
420
49%
420
20%
1051
July1st to 15thNight
54%
400
14%
1600
20%
400
58%
400
23%
943
July16th to endNight
57%
440
15%
1674
18%
418
62%
418
25%
975
August1st to 15thNight
50%
584
17%
1815
13%
582
54%
582
27%
1140
August16th to endNight
51%
781
22%
2119
12%
781
55%
781
33%
1329
September1st to 15thNight
45%
840
20%
2190
10%
840
50%
840
33%
1398
September16th to endNight
46%
782
27%
2159
16%
782
54%
782
34%
1293
October1st to 15thNight
35%
780
21%
2187
10%
780
45%
780
25%
1436
October16th to endNight
24%
832
19%
2704
8%
832
38%
832
20%
1720
November1st to 15thNight
28%
820
22%
2667
10%
820
44%
820
21%
1693
November16th to endNight
26%
840
21%
2730
9%
840
40%
840
20%
1731
December1st to 15thNight
19%
840
19%
2919
6%
840
35%
840
17%
1897
December16th to endNight
17%
896
18%
3136
5%
896
33%
896
15%
2074

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%6%25%42445%6%39%
55985
Night
17%6%25%424446%40%
54877
Cloud CoverDay
17%6%2442445%6%40%
55995
Night
17%6%25%424446%40%
54882
TransparencyDay
44%412%22%14%1
55673
Night
44%411%23%14%2
54707
SeeingDay
22%15%31%19%7%2
8413
Night
21%12%30%25%8%
17304

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
16%7%2442435%6%42%
1672
16th to endDay
15%7%25%435%446%40%
1792
February1st to 15thDay
17%8%36%43446%6%36%
1907
16th to endDay
13%10%35%6%24445%38%
1840
March1st to 15thDay
20%9%35%5%23346%34%
2115
16th to endDay
15%8%35%32335%5%43%
2524
April1st to 15thDay
18%8%25%424346%39%
2512
16th to endDay
20%6%25%424346%38%
2674
May1st to 15thDay
25%7%25%5%24446%31%
2722
16th to endDay
19%6%35%4345%5%7%34%
3029
June1st to 15thDay
24%7%25%43445%6%33%
2940
16th to endDay
18%6%25%5%35%5%5%7%34%
2940
July1st to 15thDay
12%424435%5%6%9%39%
2940
16th to endDay
13%5%25%5%35%6%6%7%38%
3102
August1st to 15thDay
13%5%245%345%6%9%38%
2701
16th to endDay
11%414425%5%6%8%44%
2784
September1st to 15thDay
14%5%15%424447%45%
2430
16th to endDay
14%5%13323345%53%
2156
October1st to 15thDay
20%7%25%42434441%
2103
16th to endDay
18%6%2443435%5%43%
1872
November1st to 15thDay
21%5%23322347%43%
1851
16th to endDay
21%6%14323345%42%
1890
December1st to 15thDay
18%6%345%23445%40%
1697
16th to endDay
22%9%345%2224437%
1792
January1st to 15thNight
15%7%25%33445%6%40%
2926
16th to endNight
14%9%36%5%3445%5%38%
3136
February1st to 15thNight
14%9%35%5%35%5%46%36%
2607
16th to endNight
15%9%25%5%34335%40%
2205
March1st to 15thNight
19%8%25%5%24445%36%
2481
16th to endNight
16%6%24423345%45%
2402
April1st to 15thNight
19%7%34424446%38%
2096
16th to endNight
22%7%25%423345%39%
1889
May1st to 15thNight
20%6%35%5%3445%7%33%
1890
16th to endNight
20%6%25%6%36%45%7%31%
1799
June1st to 15thNight
24%7%15%425%35%6%33%
1680
16th to endNight
18%6%245%235%5%7%38%
1680
July1st to 15thNight
12%4245%36%45%9%41%
1680
16th to endNight
12%414425%5%8%9%41%
1770
August1st to 15thNight
12%5%144345%6%9%41%
1825
16th to endNight
13%32433445%7%46%
2119
September1st to 15thNight
13%414423446%48%
2190
16th to endNight
15%313323346%52%
2159
October1st to 15thNight
18%5%24424445%42%
2187
16th to endNight
20%6%14423446%41%
2704
November1st to 15thNight
19%5%24424435%43%
2667
16th to endNight
18%6%24423346%42%
2730
December1st to 15thNight
19%7%35%423345%38%
2919
16th to endNight
20%7%25%423445%37%
3136

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
16%7%2442345%5%43%
1672
16th to endDay
15%7%25%415%45%6%40%
1792
February1st to 15thDay
17%7%36%42445%7%36%
1907
16th to endDay
14%10%35%5%2445%5%38%
1840
March1st to 15thDay
21%8%25%424446%34%
2125
16th to endDay
15%8%25%324346%42%
2524
April1st to 15thDay
18%7%25%433446%39%
2512
16th to endDay
20%7%25%434445%39%
2674
May1st to 15thDay
24%6%25%5%34446%32%
2722
16th to endDay
19%5%25%43445%7%35%
3029
June1st to 15thDay
25%5%245%2445%7%33%
2940
16th to endDay
17%6%25%5%345%5%7%35%
2940
July1st to 15thDay
12%424435%6%7%8%40%
2940
16th to endDay
12%425%5%35%6%6%8%39%
3102
August1st to 15thDay
12%4245%35%5%6%9%39%
2701
16th to endDay
10%4144345%6%9%45%
2784
September1st to 15thDay
13%5%24433446%46%
2430
16th to endDay
14%5%13313345%52%
2156
October1st to 15thDay
21%5%2442334442%
2103
16th to endDay
18%5%2443435%5%43%
1872
November1st to 15thDay
21%5%23323346%43%
1851
16th to endDay
21%6%24323345%43%
1890
December1st to 15thDay
19%5%25%424345%41%
1697
16th to endDay
23%9%34323235%36%
1792
January1st to 15thNight
15%7%3442445%6%40%
2926
16th to endNight
15%9%35%5%2445%5%38%
3136
February1st to 15thNight
15%9%35%5%35%445%37%
2600
16th to endNight
16%9%25%5%24435%40%
2205
March1st to 15thNight
20%8%25%5%25%445%36%
2494
16th to endNight
16%6%25%423345%45%
2401
April1st to 15thNight
19%7%34424447%37%
2096
16th to endNight
22%6%25%423345%39%
1889
May1st to 15thNight
20%6%26%5%345%5%7%33%
1890
16th to endNight
20%6%26%5%35%5%5%7%30%
1799
June1st to 15thNight
24%6%244245%46%32%
1680
16th to endNight
18%6%2442346%7%38%
1680
July1st to 15thNight
12%425%5%35%46%7%40%
1680
16th to endNight
12%4145%25%5%7%8%40%
1770
August1st to 15thNight
13%5%245%345%6%8%42%
1825
16th to endNight
14%41442445%8%46%
2119
September1st to 15thNight
14%424433447%47%
2190
16th to endNight
14%414323346%52%
2159
October1st to 15thNight
17%5%25%423346%42%
2187
16th to endNight
20%415%423445%42%
2704
November1st to 15thNight
19%5%24423435%43%
2667
16th to endNight
19%5%24423346%43%
2730
December1st to 15thNight
20%7%25%423446%39%
2919
16th to endNight
20%7%25%433445%38%
3136

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
41%5%9%24%16%2
1673
16th to endDay
43%312%23%14%1
1792
February1st to 15thDay
46%413%22%11%1
1910
16th to endDay
47%310%20%15%2
1840
March1st to 15thDay
51%311%17%12%2
2125
16th to endDay
43%27%20%18%6%
2524
April1st to 15thDay
46%39%20%15%4
2512
16th to endDay
47%39%19%16%2
2674
May1st to 15thDay
53%48%17%14%1
2722
16th to endDay
46%6%13%19%11%2
3033
June1st to 15thDay
50%5%11%20%11%1
2940
16th to endDay
46%5%12%21%13%
2940
July1st to 15thDay
36%7%14%24%16%
2791
16th to endDay
40%5%16%22%13%1
2935
August1st to 15thDay
40%6%17%24%9%
2687
16th to endDay
34%415%27%16%1
2784
September1st to 15thDay
37%5%11%25%17%1
2430
16th to endDay
34%39%27%22%2
2156
October1st to 15thDay
45%38%25%14%2
2103
16th to endDay
42%310%26%15%1
1872
November1st to 15thDay
41%312%25%14%1
1851
16th to endDay
44%313%19%17%1
1890
December1st to 15thDay
45%313%21%15%
1697
16th to endDay
50%310%19%13%1
1792
January1st to 15thNight
42%5%11%23%13%2
2926
16th to endNight
46%311%20%14%2
3136
February1st to 15thNight
48%311%20%14%1
2608
16th to endNight
46%310%22%13%3
2205
March1st to 15thNight
50%38%21%13%2
2494
16th to endNight
41%29%17%22%5%
2402
April1st to 15thNight
46%47%20%18%2
2096
16th to endNight
48%39%19%14%4
1889
May1st to 15thNight
48%5%9%19%13%2
1890
16th to endNight
52%6%12%17%10%1
1801
June1st to 15thNight
51%5%10%20%10%1
1680
16th to endNight
44%5%13%22%13%1
1680
July1st to 15thNight
38%6%14%25%14%
1600
16th to endNight
36%6%16%28%11%
1674
August1st to 15thNight
38%6%14%24%14%
1815
16th to endNight
35%5%11%27%19%
2119
September1st to 15thNight
35%5%11%28%17%1
2190
16th to endNight
33%47%32%20%2
2159
October1st to 15thNight
42%411%24%14%3
2187
16th to endNight
43%310%27%12%1
2704
November1st to 15thNight
42%410%23%16%2
2667
16th to endNight
43%313%23%14%1
2730
December1st to 15thNight
47%312%23%13%
2919
16th to endNight
48%310%21%14%1
3136

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
22%28%31%13%3
120
16th to endDay
25%25%39%10%
128
February1st to 15thDay
28%18%35%14%2
321
16th to endDay
21%25%30%17%4
343
March1st to 15thDay
28%21%33%12%4
390
16th to endDay
20%24%32%13%5%2
416
April1st to 15thDay
30%21%27%11%7%1
390
16th to endDay
28%17%30%13%7%2
379
May1st to 15thDay
32%17%29%13%5%2
408
16th to endDay
22%18%32%18%5%1
459
June1st to 15thDay
22%16%36%18%5%
435
16th to endDay
21%12%40%16%6%1
435
July1st to 15thDay
12%7%36%29%10%3
425
16th to endDay
15%5%34%29%11%3
454
August1st to 15thDay
16%8%30%24%15%3
418
16th to endDay
14%5%31%29%12%6%
460
September1st to 15thDay
17%9%29%26%11%5%
435
16th to endDay
17%9%31%21%8%10%
378
October1st to 15thDay
25%11%22%26%12%2
363
16th to endDay
23%18%32%18%6%
336
November1st to 15thDay
27%14%27%21%6%1
325
16th to endDay
28%16%24%21%6%1
330
December1st to 15thDay
15%24%38%15%5%
137
16th to endDay
32%25%31%10%
128
January1st to 15thNight
20%19%37%19%3
840
16th to endNight
23%19%34%19%3
896
February1st to 15thNight
20%19%40%17%2
824
16th to endNight
22%17%33%22%4
735
March1st to 15thNight
25%15%37%18%2
840
16th to endNight
21%15%33%21%6%
896
April1st to 15thNight
24%16%31%23%3
838
16th to endNight
25%13%31%22%7%
643
May1st to 15thNight
23%9%32%26%7%1
630
16th to endNight
24%8%29%28%8%1
487
June1st to 15thNight
27%6%25%29%9%
420
16th to endNight
22%125%35%14%
420
July1st to 15thNight
15%120%43%18%1
400
16th to endNight
13%218%44%18%2
440
August1st to 15thNight
14%323%40%16%
584
16th to endNight
15%322%35%19%2
781
September1st to 15thNight
15%426%34%18%1
840
16th to endNight
17%426%27%19%4
782
October1st to 15thNight
20%8%27%26%15%1
780
16th to endNight
24%14%31%22%6%
832
November1st to 15thNight
22%13%30%23%7%1
820
16th to endNight
21%17%29%24%6%
840
December1st to 15thNight
24%14%36%20%4
840
16th to endNight
25%16%34%19%2
896
Page generated at 2019-09-17 21:12:19. Version ac04

Copyright 2019 A. Danko


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